Compare commits
7 Commits
2016_editi
...
master
| Author | SHA1 | Date |
|---|---|---|
 Elf M. Sternberg
|
82af8f6a44 | |
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Elf M. Sternberg
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fc2c77b56d | |
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Elf M. Sternberg
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863f977ad0 | |
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Elf M. Sternberg
|
d0af7f22e6 | |
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Elf M. Sternberg
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1c417adc6e | |
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Elf M. Sternberg
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1f6c1e0b46 | |
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Elf M. Sternberg
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1667a0e94d |
|
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@ -4,3 +4,10 @@
|
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.#*
|
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.DS_Store
|
||||
*~
|
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node_modules/*
|
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bower_components/*
|
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npm-debug.log
|
||||
docs/*.html
|
||||
docs/*.tex
|
||||
htdocs/lib
|
||||
package.yml
|
||||
|
|
|
|||
101
Makefile
101
Makefile
|
|
@ -1,58 +1,75 @@
|
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.SUFFIXES: .nw .js .pdf .html .tex
|
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.PHONY: setup store serve
|
||||
|
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NOTANGLE= notangle
|
||||
NOWEAVE= noweave
|
||||
ECHO= /bin/echo
|
||||
ECHO= echo
|
||||
|
||||
all: index.html store.js
|
||||
LIBS:= htdocs/lib/underscore.js htdocs/lib/jquery.js htdocs/lib/backbone.js
|
||||
|
||||
.nw.html:
|
||||
$(NOWEAVE) -filter l2h -delay -x -index -autodefs c -html $*.nw > $*.html
|
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all: htdocs/index.html htdocs/store.js htdocs/data/items.json
|
||||
@if [ ! -e "./htdocs/lib" ]; then \
|
||||
echo "Please do 'make setup' before continuing"; \
|
||||
exit 1; \
|
||||
fi
|
||||
|
||||
.nw.tex:
|
||||
$(NOWEAVE) -x -delay $*.nw > $*.tex #$
|
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serve: all
|
||||
./bin/autoreload
|
||||
|
||||
.tex.pdf:
|
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xelatex $*.tex; \
|
||||
while grep -s 'Rerun to get cross-references right' $*.log; \
|
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store: all
|
||||
|
||||
htdocs/lib:
|
||||
mkdir -p htdocs/lib
|
||||
|
||||
htdocs/lib/underscore.js: htdocs/lib
|
||||
cp bower_components/underscore/underscore.js htdocs/lib
|
||||
|
||||
htdocs/lib/jquery.js: htdocs/lib
|
||||
cp bower_components/jquery/dist/jquery.js htdocs/lib
|
||||
|
||||
htdocs/lib/backbone.js:
|
||||
cp bower_components/backbone/backbone.js htdocs/lib
|
||||
|
||||
install:
|
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npm install
|
||||
./node_modules/bower/bin/bower install jquery underscore backbone
|
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|
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setup: install $(LIBS)
|
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|
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docs:
|
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mkdir -p docs
|
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|
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htdocs/index.html: src/backbonestore.nw
|
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$(NOTANGLE) -c -Rindex.html src/backbonestore.nw > htdocs/index.html
|
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|
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htdocs/store.js: src/backbonestore.nw
|
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$(NOTANGLE) -c -Rstore.js src/backbonestore.nw > htdocs/store.js
|
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|
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docs/backbonestore.tex: docs src/backbonestore.nw
|
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${NOWEAVE} -x -delay src/backbonestore.nw > docs/backbonestore.tex
|
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|
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docs/backbonestore.pdf: docs/backbonestore.tex
|
||||
xelatex docs/backbonestore.tex; \
|
||||
while grep -s 'Rerun to get cross-references right' ./backbonestore.log; \
|
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do \
|
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xelatex *$.tex; \
|
||||
xelatex docs/backbonestore.tex; \
|
||||
done
|
||||
mv backbonestore.pdf docs
|
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rm -f ./backbonestore.log ./backbonestore.aux ./backbonestore.out
|
||||
|
||||
.nw.js:
|
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@ $(ECHO) $(NOTANGLE) -c -R$@ $<
|
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@ - $(NOTANGLE) -c -R$@ $< > $*.nw-js-tmp
|
||||
@ if [ -s "$*.nw-js-tmp" ]; then \
|
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mv $*.nw-js-tmp $@; \
|
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else \
|
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echo "$@ not found in $<"; \
|
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rm $*.nw-js-tmp; \
|
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fi
|
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pdf: docs/backbonestore.pdf
|
||||
|
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store.js: backbonestore.nw
|
||||
@ $(ECHO) $(NOTANGLE) -c -R$@ $<
|
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@ - $(NOTANGLE) -c -R$@ $< > $*.nw-html-tmp
|
||||
@ if [ -s "$*.nw-html-tmp" ]; then \
|
||||
mv $*.nw-html-tmp $@; \
|
||||
else \
|
||||
echo "$@ not found in $<"; \
|
||||
rm $*.nw-tmp; \
|
||||
fi
|
||||
|
||||
index.html: backbonestore.nw
|
||||
@ $(ECHO) $(NOTANGLE) -c -R$@ $<
|
||||
@ - $(NOTANGLE) -c -R$@ $< > $*.nw-html-tmp
|
||||
@ if [ -s "$*.nw-html-tmp" ]; then \
|
||||
mv $*.nw-html-tmp $@; \
|
||||
else \
|
||||
echo "$@ not found in $<"; \
|
||||
rm $*.nw-tmp; \
|
||||
fi
|
||||
docs/backbonestore.html: docs src/backbonestore.nw
|
||||
$(NOWEAVE) -filter l2h -delay -x -autodefs c -html src/backbonestore.nw > docs/backbonestore.html
|
||||
|
||||
html: docs/backbonestore.html
|
||||
|
||||
clean:
|
||||
- rm -f *.tex *.dvi *.aux *.toc *.log *.out *.html *.js
|
||||
- rm -f htdocs/*.js htdocs/*.html docs/*.tex docs/*.dvi docs/*.aux docs/*.toc docs/*.log docs/*.out
|
||||
|
||||
distclean: clean
|
||||
- rm -fr ./htdocs/lib
|
||||
|
||||
realclean: distclean
|
||||
- rm -fr docs
|
||||
|
||||
realclean: clean
|
||||
- rm -f *.pdf
|
||||
|
||||
|
|
|
|||
35
README
35
README
|
|
@ -1,35 +0,0 @@
|
|||
The Backbone Store is a simple demonstration application, a Backbone.js
|
||||
version of the Sammy.js tutorial.
|
||||
|
||||
## Installation
|
||||
|
||||
The Backbone store must be installed under a webserver in order to
|
||||
operate correctly. Chrome, especially, will not initialize the
|
||||
application from the filesystem. Just unpack it in a target directory
|
||||
of your choosing and then browse to that directory.
|
||||
|
||||
## Branches
|
||||
|
||||
There are two major development branches for The Backbone Store.
|
||||
|
||||
Branch 'master' uses HTML, CSS, and Javascript.
|
||||
|
||||
Branch 'modern' uses HAML, Stylus, and Coffee.
|
||||
|
||||
## Copyright
|
||||
|
||||
Store.js is entirely my own work, and is Copyright (c) 2010 Elf
|
||||
M. Sternberg. Included libraries are covered by their respective
|
||||
copyright holders, and are used with permission of the licenses
|
||||
included. Store.js is intended for educational purposes only, rather
|
||||
than to be working code, and is hereby licensed under the Creative
|
||||
Commons Attribution Non-Commercial Share Alike (by-nc-sa) licence.
|
||||
|
||||
The images contained herein are derivative works of photographs
|
||||
licensed under Creative Commons licences for non-commercial purposes.
|
||||
|
||||
## Contribution
|
||||
|
||||
Please look in backbonestore.nw for the base code. Backbonestore.nw
|
||||
is produced using the Noweb Literate Programming toolkit by Norman
|
||||
Ramsey (http://www.cs.tufts.edu/~nr/noweb/).
|
||||
|
|
@ -0,0 +1,66 @@
|
|||
# About
|
||||
|
||||
The Backbone Store is a tutorial and demonstration application for
|
||||
BackboneJS, a javascript framework for managing data-driven websites.
|
||||
|
||||
## Installation
|
||||
|
||||
After checking out the source code, type
|
||||
|
||||
$ make setup all serve
|
||||
|
||||
This will automatically run the NPM and Bower install scripts, placing
|
||||
the correct libraries into the target tree, build the actual application
|
||||
from the original source material, and start a local server.
|
||||
|
||||
## Requirements
|
||||
|
||||
The build tool relies upon GNU Make and node-js. It also uses the NoWeb
|
||||
Literate Programming documentation tools, and building the documentation
|
||||
from source requires Xelatex be installed as well.
|
||||
|
||||
The command 'make serve' probably only works under a fairly modern
|
||||
Linux, as it is dependent upon the kernel's inotify facility.
|
||||
|
||||
## Branches
|
||||
|
||||
There are two major development branches for The Backbone Store.
|
||||
|
||||
Branch 'master' uses HTML, CSS, and Javascript.
|
||||
|
||||
Branch 'modern' uses HAML, Stylus, and Coffee.
|
||||
|
||||
## Changelog
|
||||
|
||||
### Changes from 2.0
|
||||
|
||||
Version 3.0 has the following notable changes:
|
||||
* Replace __super__ with prototype
|
||||
* Replace Backbone-generated internal IDs with supplied IDs
|
||||
* Updates the use of Deferred
|
||||
* Updates to the current Underscore Template mechanism
|
||||
|
||||
### Changes from 1.0
|
||||
|
||||
Version 2.0 has the following notable changes:
|
||||
* Use of jQuery animations
|
||||
* Better Styling
|
||||
* Proper event management. Version 1.0 was just doin' it WRONG.
|
||||
|
||||
## Copyright
|
||||
|
||||
Store.js is entirely my own work, and is Copyright (c) 2010 Elf
|
||||
M. Sternberg. Included libraries are covered by their respective
|
||||
copyright holders, and are used with permission of the licenses
|
||||
included. Store.js is intended for educational purposes only, rather
|
||||
than to be working code, and is hereby licensed under the Creative
|
||||
Commons Attribution Non-Commercial Share Alike (by-nc-sa) licence.
|
||||
|
||||
The images contained herein are derivative works of photographs
|
||||
licensed under Creative Commons licences for non-commercial purposes.
|
||||
|
||||
## Contribution
|
||||
|
||||
Please look in backbonestore.nw for the base code. Backbonestore.nw
|
||||
is produced using the Noweb Literate Programming toolkit by Norman
|
||||
Ramsey (http://www.cs.tufts.edu/~nr/noweb/).
|
||||
1154
backbone.js
1154
backbone.js
File diff suppressed because it is too large
Load Diff
751
backbonestore.nw
751
backbonestore.nw
|
|
@ -1,751 +0,0 @@
|
|||
% -*- Mode: noweb; noweb-code-mode: javascript-mode ; noweb-doc-mode: latex-mode -*-
|
||||
\documentclass{article}
|
||||
\usepackage{noweb}
|
||||
\usepackage[T1]{fontenc}
|
||||
\usepackage{hyperref}
|
||||
\begin{document}
|
||||
|
||||
% Generate code and documentation with:
|
||||
%
|
||||
% noweave -filter l2h -delay -x -html backbonestore.nw | htmltoc > backbonestore.html
|
||||
% notangle -Rstore.js backbonestore.nw > store.js
|
||||
% notangle -Rindex.html backbonestore.nw > index.html
|
||||
|
||||
\section{Introduction}
|
||||
|
||||
This is version 2.0 of \textbf{The Backbone Store}, a brief tutorial
|
||||
on using [[backbone.js]].
|
||||
|
||||
\nwanchorto{http://documentcloud.github.com/backbone/}{Backbone.js} is
|
||||
a popular Model-View-Controller (MVC) library that provides a
|
||||
framework for creating data-rich, single-page web applications. It
|
||||
provides (1) a two-layer scheme for separating data from presentation,
|
||||
(2) a means of automatically synchronizing data with a server in a
|
||||
RESTful manner, and (3) a mechanism for making some views bookmarkable
|
||||
and navigable.
|
||||
|
||||
There are a number of other good tutorials for Backbone (See:
|
||||
\nwanchorto{http://www.plexical.com/blog/2010/11/18/backbone-js-tutorial/}{Meta
|
||||
Cloud},
|
||||
\nwanchorto{http://andyet.net/blog/2010/oct/29/building-a-single-page-app-with-backbonejs-undersc/?utm_source=twitterfeed&utm_medium=twitter}{\&Yet's
|
||||
Tutorial},
|
||||
\nwanchorto{http://bennolan.com/2010/11/24/backbone-jquery-demo.html}{Backbone
|
||||
Mobile} (which is written in
|
||||
\nwanchorto{http://jashkenas.github.com/coffee-script/}{Coffee}), and
|
||||
\nwanchorto{http://joshbohde.com/2010/11/25/backbonejs-and-django/}{Backbone
|
||||
and Django}. However, a couple of months ago I was attempting to
|
||||
learn Sammy.js, a library very similar to Backbone, and they had a
|
||||
nifty tutorial called
|
||||
\nwanchorto{http://code.quirkey.com/sammy/tutorials/json_store_part1.html}{The
|
||||
JsonStore}.
|
||||
|
||||
In the spirit of The JSON Store, I present The Backbone Store.
|
||||
|
||||
\subsection{Literate Program}
|
||||
|
||||
A note: this article was written with the
|
||||
\nwanchorto{http://en.wikipedia.org/wiki/Literate_programming}{Literate
|
||||
Programming} toolkit
|
||||
\nwanchorto{http://www.cs.tufts.edu/~nr/noweb/}{Noweb}. Where you see
|
||||
something that looks like \\<\\<this\\>\\>, it's a placeholder for code
|
||||
described elsewhere in the document. Placeholders with an equal sign
|
||||
at the end of them indicate the place where that code is defined. The
|
||||
link (U->) indicates that the code you're seeing is used later in the
|
||||
document, and (<-U) indicates it was used earlier but is being defined
|
||||
here.
|
||||
|
||||
\subsection{Revision}
|
||||
|
||||
This is version 2.0 of \textit{The Backbone Store}. It includes
|
||||
changes to the store based upon a better understanding of what
|
||||
Backbone.js can do. This version uses jQuery 1.6.2 and Backbone
|
||||
0.5.2.
|
||||
|
||||
\subsection{The Store}
|
||||
|
||||
To demonstrate the basics of Backbone, I'm going to create a simple
|
||||
one-page application, a store for record albums, with two unique
|
||||
views: a list of all products and a product detail view. I will also
|
||||
put a shopping cart widget on the page that shows the user how many
|
||||
products he or she has dropped into the cart. I'll use jQuery's
|
||||
[[fadeIn()]] and [[fadeOut()]] features to transition between the
|
||||
catalog and the product detail pages.
|
||||
|
||||
\subsection{Models, Collections, and Controllers}
|
||||
|
||||
Backbone's data layer provides two classes, [[Model]] and
|
||||
[[Collection]]. To use the Model, you inherit from it, modify the
|
||||
subclasss as needed, and then create new objects from the subclass by
|
||||
constructing the model with a JSON object. You modify the object by
|
||||
calling [[get()]] or [[set()]] on named attributes, rather than on the
|
||||
Model object directly; this allows Model to notify other interested
|
||||
objects that the object has been changed. And Model comes with
|
||||
[[fetch()]] and [[save()]] methods that will automatically pull or
|
||||
push a JSON representatino of the model to a server, if the Model has
|
||||
[[url]] as one of its attributes.
|
||||
|
||||
Collections are just that: lists of objects of a specific model. You
|
||||
extend the Collection class in a child class, and as you do you inform
|
||||
the Collection of what Model it represents, what URL you use to
|
||||
push/pull the full list of objects, and on what field the list should
|
||||
be sorted by default. If you attempt to add a raw JSON object to a
|
||||
collection, it constructs a corresponding Model object out of the JSON
|
||||
and manipulates that.
|
||||
|
||||
I will be getting the data from a simplified JSON file that comes in
|
||||
the download; it contains six record albums that the store sells.
|
||||
(Unlike the JSON store, these albums do not exist; the covers were
|
||||
generated during a round of
|
||||
\nwanchorto{http://elfs.livejournal.com/756709.html}{The Album Cover
|
||||
Game}, a meme one popular with graphic designers.)
|
||||
|
||||
For our purposes, then, we have a [[Product]] and a
|
||||
[[ProductCollection]]. A popular convention in Backbone is to use
|
||||
concrete names for models, and Name\textbf{Collection} for the
|
||||
collection.
|
||||
|
||||
Models are duck-typed by default; they do not care what you put into
|
||||
them. So all I need to say is that a [[Product]] is-a [[Model]]. The
|
||||
Collection is straightforward as well; I tell it what model it
|
||||
represents, override the [[initialize()]] method (which is empty in
|
||||
the Backbone default) to inform this Collection that it has a url, and
|
||||
create the comparator function for default sorting.
|
||||
|
||||
<<product models>>=
|
||||
var Product = Backbone.Model.extend({})
|
||||
|
||||
var ProductCollection = Backbone.Collection.extend({
|
||||
model: Product,
|
||||
|
||||
initialize: function(models, options) {
|
||||
this.url = options.url;
|
||||
},
|
||||
|
||||
comparator: function(item) {
|
||||
return item.get('title');
|
||||
}
|
||||
});
|
||||
@
|
||||
|
||||
|
||||
|
||||
For the shopping cart, our cart will hold [[Item]]s, and the cart
|
||||
itself will be an [[ItemCollection]]. Shoppings carts are a little
|
||||
odd; the convention is that an [[Item]] is not a single instance of a
|
||||
product, but a reference to the products and a quantity.
|
||||
|
||||
One thing we will be doing is changing the quantity, so I have
|
||||
provided a convenience function for the Item that allows you to do
|
||||
that. Now, no client classes such as Views need to know how the
|
||||
quantity is updated.
|
||||
|
||||
Also, it would be nice to know the total price of the Item.
|
||||
|
||||
<<cart models>>=
|
||||
var Item = Backbone.Model.extend({
|
||||
update: function(amount) {
|
||||
this.set({'quantity': amount}, {silent: true});
|
||||
this.collection.trigger('change', this);
|
||||
},
|
||||
price: function() {
|
||||
console.log(this.get('product').get('title'), this.get('quantity'));
|
||||
return this.get('product').get('price') * this.get('quantity');
|
||||
}
|
||||
});
|
||||
|
||||
@
|
||||
|
||||
The [[ItemCollection]] is a little trickier. It is entirely
|
||||
client-side; it has no synchronization with the backend at all. But
|
||||
it does have a model.
|
||||
|
||||
The [[ItemCollection]] must be able to find an Item in the cart to
|
||||
update when a view needs it. If the Item is not in the Collection, it
|
||||
must create one. The method [[getOrCreateItemForProduct]] does this.
|
||||
It uses the [[detect()]] method, a method [[Collection]] inherits from
|
||||
Backbone's one dependency, Underscore.js; [[detect()]] returns the
|
||||
first [[Item]] in the [[ItemCollection]] for which the function
|
||||
returns [[true]]. Also, when I have to create a new Item, I want to
|
||||
add it to the collection, and I pass the parameter [[silent]], which
|
||||
prevents the Collection from notifying event subscribers that the
|
||||
collection has changed. Since this is an Item with zero objects in
|
||||
it, this is not a change to what the collection represents, and I
|
||||
don't want Views to react without having to.
|
||||
|
||||
Finally, I add two methods that return the total count of objects in
|
||||
the collection (not [[Items]], but actual [[Products]]), and the total
|
||||
cost of those items in the cart. The Underscore method [[reduce()]]
|
||||
does this by taking a function for adding progressive items, and a
|
||||
starting value.
|
||||
|
||||
<<cart models>>=
|
||||
var ItemCollection = Backbone.Collection.extend({
|
||||
model: Item,
|
||||
|
||||
getOrCreateItemForProduct: function(product) {
|
||||
var i,
|
||||
pid = product.get('id'),
|
||||
o = this.detect(function(obj) {
|
||||
return (obj.get('product').get('id') == pid);
|
||||
});
|
||||
if (o) {
|
||||
return o;
|
||||
}
|
||||
i = new Item({'product': product, 'quantity': 0})
|
||||
this.add(i, {silent: true})
|
||||
return i;
|
||||
},
|
||||
|
||||
getTotalCount: function() {
|
||||
return this.reduce(function(memo, obj) {
|
||||
return obj.get('quantity') + memo; }, 0);
|
||||
},
|
||||
|
||||
getTotalCost: function() {
|
||||
return this.reduce(function(memo, obj) {
|
||||
return obj.price() + memo; }, 0);
|
||||
}
|
||||
});
|
||||
|
||||
@
|
||||
|
||||
\subsection {Views}
|
||||
|
||||
Backbone Views are simple policy objects. They have a root DOM
|
||||
element, the contents of which they manipulate and to which they
|
||||
listen for events, and a model or collection they represent within
|
||||
that element. Views are not rigid; it's just Javascript and the DOM,
|
||||
and you can hook external events as needed.
|
||||
|
||||
More importantly, a View is sensitive to events \textit{within its
|
||||
model or collection}, and can respond to changes automatically.
|
||||
This way, if you have a rich data ecosystem, when changes to one data
|
||||
item results in a cascade of changes throughout your datasets, the
|
||||
views will receive ``change'' events and can update themselves
|
||||
accordingly.
|
||||
|
||||
I will show how this works with the shopping cart widget.
|
||||
|
||||
To achieve the [[fadeIn/fadeOut]] animations and enforce consistency,
|
||||
I'm going to do some basic object-oriented programming. I'm going to
|
||||
create a base class that contains knowledge about the main area into
|
||||
which all views are rendered, and that manages these transitions.
|
||||
|
||||
With this technique, you can do lots of navigation-related tricks: you
|
||||
can highlight where the user is in breadcrumb-style navigation; you
|
||||
can change the class and highlight an entry on a nav bar; you can add
|
||||
and remove tabs from the top of the viewport as needed.
|
||||
|
||||
<<base view>>=
|
||||
var _BaseView = Backbone.View.extend({
|
||||
parent: $('#main'),
|
||||
className: 'viewport',
|
||||
|
||||
@
|
||||
|
||||
The above says that I am creating a class called \texttt{BaseView} and
|
||||
defining two fields. The first, 'parent', will be used by all child
|
||||
views to identify into which DOM object the View's root element will
|
||||
be rendered. The second defines a common class we will use for the
|
||||
purpose of identifying these views to jQuery. Backbone automatically
|
||||
creates a new [[DIV]] object with the class 'viewport' when a view
|
||||
constructor is called. It will be our job to attach that [[DIV]] to
|
||||
the DOM. In the HTML, you will see the [[DIV\#main]] object where most
|
||||
of the work will be rendered.
|
||||
|
||||
<<base view>>=
|
||||
initialize: function() {
|
||||
this.el = $(this.el);
|
||||
this.el.hide();
|
||||
this.parent.append(this.el);
|
||||
return this;
|
||||
},
|
||||
|
||||
@
|
||||
%$
|
||||
|
||||
The method above ensures that the element is rendered, but not
|
||||
visible, and contained within the [[DIV\#main]]. Note also that
|
||||
the element is not a sacrosanct object; the Backbone.View is more a
|
||||
collection of standards than a mechanism of enforcement, and so
|
||||
defining it from a raw DOM object to a jQuery object will not break
|
||||
anything.
|
||||
|
||||
Next, we will define the hide and show functions:
|
||||
|
||||
<<base view>>=
|
||||
hide: function() {
|
||||
if (this.el.is(":visible") === false) {
|
||||
return null;
|
||||
}
|
||||
promise = $.Deferred(_.bind(function(dfd) {
|
||||
this.el.fadeOut('fast', dfd.resolve)}, this));
|
||||
return promise.promise();
|
||||
},
|
||||
|
||||
show: function() {
|
||||
if (this.el.is(':visible')) {
|
||||
return;
|
||||
}
|
||||
promise = $.Deferred(_.bind(function(dfd) {
|
||||
this.el.fadeIn('fast', dfd.resolve) }, this))
|
||||
return promise.promise();
|
||||
}
|
||||
});
|
||||
|
||||
@
|
||||
|
||||
\textbf{Deferred} is a new feature of jQuery. It is a different
|
||||
mechanism for invoking callbacks by attaching attributes and behavior
|
||||
to the callback function. By using this, we can say thing like
|
||||
``\textit{When} everything is hidden (when every deferred returned
|
||||
from \textbf{hide} has been resolved), \textit{then} show the
|
||||
appropriate viewport.'' Deferreds are incredibly powerful, and this
|
||||
is a small taste of what can be done with them.
|
||||
|
||||
Before we move on, let's take a look at the HTML we're going to use
|
||||
for our one-page application:
|
||||
|
||||
<<index.html>>=
|
||||
<!DOCTYPE html>
|
||||
<html xmlns="http://www.w3.org/1999/xhtml">
|
||||
<head>
|
||||
<title>
|
||||
The Backbone Store
|
||||
</title>
|
||||
<link rel="stylesheet" href="jsonstore.css" type="text/css">
|
||||
<<product list template>>
|
||||
<<product detail template>>
|
||||
<<cart template>>
|
||||
</head>
|
||||
<body>
|
||||
<div id="container">
|
||||
<div id="header">
|
||||
<h1>
|
||||
The Backbone Store
|
||||
</h1>
|
||||
|
||||
<div class="cart-info">
|
||||
</div>
|
||||
</div>
|
||||
|
||||
<div id="main"> </div>
|
||||
</div>
|
||||
<script src="jquery-1.6.2.min.js" type="text/javascript"></script>
|
||||
<script src="underscore.js" type="text/javascript"></script>
|
||||
<script src="backbone.js" type="text/javascript"></script>
|
||||
<script src="store.js" type="text/javascript"></script>
|
||||
</body>
|
||||
</html>
|
||||
@
|
||||
|
||||
It's not much to look at, but already you can see where that
|
||||
[[DIV\#main]] goes, as well as where we are putting our templates.
|
||||
The [[DIV\#main]] will host a number of viewports, only one of
|
||||
which will be visible at any given time.
|
||||
|
||||
Our first view is going to be the product list view, named, well,
|
||||
guess. Or just look down a few lines.
|
||||
|
||||
This gives us a chance to discuss one of the big confusions new
|
||||
Backbone users frequently have: \textit{What is \texttt{render()}
|
||||
for?}. Render is not there to show or hide the view.
|
||||
\texttt{Render()} is there to \textit{change the view when the
|
||||
underlying data changes}. It renders the data into a view. In our
|
||||
functionality, we use the parent class's \texttt{show()} and
|
||||
\texttt{hide()} methods to actually show the view.
|
||||
|
||||
That call to [[\_super\_]] is a Backbone idiom for calling a method on
|
||||
the parent object. It is, as far as anyone knows, the only way to
|
||||
invoke a superclass method if it has been redefined in a subclass.
|
||||
It is rather ugly, but useful.
|
||||
|
||||
<<product list view>>=
|
||||
var ProductListView = _BaseView.extend({
|
||||
id: 'productlistview',
|
||||
template: $("#store_index_template").html(),
|
||||
|
||||
initialize: function(options) {
|
||||
this.constructor.__super__.initialize.apply(this, [options])
|
||||
this.collection.bind('reset', _.bind(this.render, this));
|
||||
},
|
||||
|
||||
render: function() {
|
||||
this.el.html(_.template(this.template,
|
||||
{'products': this.collection.toJSON()}))
|
||||
return this;
|
||||
}
|
||||
});
|
||||
|
||||
@
|
||||
%$
|
||||
|
||||
That \texttt{\_.template()} method is provided by undescore.js, and is
|
||||
a full-featured, javascript-based templating method. It's not the
|
||||
fastest or the most feature-complete, but it is more than adequate for
|
||||
our purposes and it means we don't have to import another library. It
|
||||
vaguely resembles ERB from Rails, so if you are familiar with that,
|
||||
you should understand this fairly easily.
|
||||
|
||||
And here is the HTML:
|
||||
|
||||
<<product list template>>=
|
||||
<script id="store_index_template" type="text/x-underscore-tmplate">
|
||||
<h1>Product Catalog</h1>
|
||||
<ul>
|
||||
<% for(i=0,l=products.length;i<l;++i) { p = products[i]; %>
|
||||
<li class="item">
|
||||
<div class="item-image">
|
||||
<a href="#item/<%= p.id %>">
|
||||
<img alt="<%= p.title %>" src="<%= p.image %>" />
|
||||
</a>
|
||||
</div>
|
||||
<div class="item-artist"><%= p.artist %></div>
|
||||
<div class="item-title"><%= p.title %></div>
|
||||
<div class="item-price">$<%= p.price %></div>
|
||||
</li>
|
||||
<% } %>
|
||||
</ul>
|
||||
</script>
|
||||
@
|
||||
%$
|
||||
|
||||
|
||||
One of the most complicated objects in our ecosystem is the product
|
||||
view. It actually does something! The prefix ought to be familiar,
|
||||
but note that we are again using [[\#main]] as our target; we will be
|
||||
showing and hiding the various [[DIV]] objects in [[\#main]] again and
|
||||
again.
|
||||
|
||||
The only trickiness here is twofold: the (rather hideous) means by
|
||||
which one calls the method of a parnt class from a child class via
|
||||
Backbone's class heirarchy (this is most definitely \textbf{not}
|
||||
Javascript standard), and keeping track of the itemcollection object,
|
||||
so we can add and change items as needed.
|
||||
|
||||
<<product detail view>>=
|
||||
var ProductView = _BaseView.extend({
|
||||
id: 'productitemview',
|
||||
template: $("#store_item_template").html(),
|
||||
initialize: function(options) {
|
||||
this.constructor.__super__.initialize.apply(this, [options])
|
||||
this.itemcollection = options.itemcollection;
|
||||
this.item = this.itemcollection.getOrCreateItemForProduct(this.model);
|
||||
return this;
|
||||
},
|
||||
|
||||
@
|
||||
%$
|
||||
|
||||
There are certain events in which we're interested: keypresses and
|
||||
clicks on the update button and the quantity form. (Okay, ``UQ''
|
||||
isn't the best for ``update quantity''. I admit that.) Note the
|
||||
peculiar syntax of ``EVENT SELECTOR'': ``methodByName'' for each
|
||||
event.
|
||||
|
||||
Backbone tells us that the only events it can track by itself are
|
||||
those that jQuery's ``delegate'' understands. As of 1.5, that seems
|
||||
to be just about all of them.
|
||||
|
||||
<<product detail view>>=
|
||||
events: {
|
||||
"keypress .uqf" : "updateOnEnter",
|
||||
"click .uq" : "update",
|
||||
},
|
||||
|
||||
@
|
||||
|
||||
And now we will deal with the update. This code ought to be fairly
|
||||
readable: the only specialness is that it's receiving an event, and
|
||||
we're ``silencing'' the call to [[cart.add()]], which means that the
|
||||
cart collection will not publish any events. There are only events
|
||||
when the item has more than zero, and that gets called on
|
||||
[[cart_item.update()]].
|
||||
|
||||
In the original tutorial, this code had a lot of responsibility for
|
||||
managing the shopping cart, looking into it and seeing if it had an
|
||||
item for this product, and there was lots of accessing the model to
|
||||
get its id and so forth. All of that has been put into the shopping
|
||||
cart model, which is where it belongs: \textit{knowledge about items
|
||||
and each item's relationship to its collection belongs in the
|
||||
collection}.
|
||||
|
||||
Look closely at the [[update()]] method. The reference [[this.\$]] is
|
||||
a special Backbone object that limits selectors to objects inside the
|
||||
element of the view. Without it, jQuery would have found the first
|
||||
input field of class 'uqf' in the DOM, not the one for this specific
|
||||
view. [[this.\$('.uqf')]] is shorthand for [[$('uqf', this.el)]], and
|
||||
helps clarify what it is you're looking for.
|
||||
|
||||
%'
|
||||
|
||||
<<product detail view>>=
|
||||
update: function(e) {
|
||||
e.preventDefault();
|
||||
this.item.update(parseInt(this.$('.uqf').val()));
|
||||
},
|
||||
|
||||
updateOnEnter: function(e) {
|
||||
if (e.keyCode == 13) {
|
||||
return this.update(e);
|
||||
}
|
||||
},
|
||||
|
||||
@
|
||||
%$
|
||||
|
||||
The render is straightforward:
|
||||
|
||||
<<product detail view>>=
|
||||
render: function() {
|
||||
this.el.html(_.template(this.template, this.model.toJSON()));
|
||||
return this;
|
||||
}
|
||||
});
|
||||
|
||||
@
|
||||
|
||||
The product detail template is fairly straightforward. There is no
|
||||
[[underscore]] magic because there are no loops.
|
||||
|
||||
<<product detail template>>=
|
||||
<script id="store_item_template" type="text/x-underscore-template">
|
||||
<div class="item-detail">
|
||||
<div class="item-image">
|
||||
<img alt="<%= title %>" src="<%= large_image %>" />
|
||||
</div>
|
||||
</div>
|
||||
<div class="item-info">
|
||||
<div class="item-artist"><%= artist %></div>
|
||||
<div class="item-title"><%= title %></div>
|
||||
<div class="item-price">$<%= price %></div>
|
||||
<form action="#/cart" method="post">
|
||||
<p>
|
||||
<label>Quantity:</label>
|
||||
<input class="uqf" name="quantity" size="2" type="text" value="1" />
|
||||
</p>
|
||||
<p>
|
||||
<input class="uq" type="submit" value="Add to Cart" />
|
||||
</p>
|
||||
</form>
|
||||
<div class="item-link">
|
||||
<a href="<%= url %>">Buy this item on Amazon</a>
|
||||
</div>
|
||||
<div class="back-link">
|
||||
<a href="#">« Back to Items</a>
|
||||
</div>
|
||||
</div>
|
||||
</script>
|
||||
@
|
||||
|
||||
So, let's talk about that shopping cart thing. We've been making the
|
||||
point that when it changes, when you call [[item.update]] within the
|
||||
product detail view, any corresponding subscribing views sholud
|
||||
automatically update.
|
||||
|
||||
<<cart widget>>=
|
||||
var CartWidget = Backbone.View.extend({
|
||||
el: $('.cart-info'),
|
||||
template: $('#store_cart_template').html(),
|
||||
|
||||
initialize: function() {
|
||||
this.collection.bind('change', _.bind(this.render, this));
|
||||
},
|
||||
|
||||
@
|
||||
%$
|
||||
|
||||
And there is the major magic. CartWidget will be initialized with the
|
||||
ItemCollection; when there is any change in the collection, the widget
|
||||
will receive the 'change' event, which will automatically trigger the
|
||||
call to the widget's [[render()]] method.
|
||||
|
||||
The render method will refill that widget's HTML with a re-rendered
|
||||
template with the new count and cost, and then wiggle it a little to
|
||||
show that it did changed:
|
||||
|
||||
<<cart widget>>=
|
||||
render: function() {
|
||||
this.el.html(
|
||||
_.template(this.template, {
|
||||
'count': this.collection.getTotalCount(),
|
||||
'cost': this.collection.getTotalCost()
|
||||
})).animate({paddingTop: '30px'})
|
||||
.animate({paddingTop: '10px'});
|
||||
}
|
||||
});
|
||||
|
||||
@
|
||||
|
||||
And the HTML for the template is dead simple:
|
||||
|
||||
<<cart template>>=
|
||||
<script id="store_cart_template" type="text/x-underscore-template">
|
||||
<p>Items: <%= count %> ($<%= cost %>)</p>
|
||||
</script>
|
||||
|
||||
@
|
||||
%$
|
||||
|
||||
Lastly, there is the [[Router]]. In Backbone, the Router is a
|
||||
specialized View for invoking other views. It listens for one
|
||||
specific event: when the [[window.location.hash]] object, the part of
|
||||
the URL after the hash symbol, changes. When the hash changes, the
|
||||
Router invokes an event handler. The Router, since its purpose is to
|
||||
control the major components of the one-page display, is also a good
|
||||
place to keep all the major components of the sytem. We'll keep track
|
||||
of the [[Views]], the [[ProductCollection]], and the
|
||||
[[ItemCollection]].
|
||||
|
||||
<<router>>=
|
||||
var BackboneStore = Backbone.Router.extend({
|
||||
views: {},
|
||||
products: null,
|
||||
cart: null,
|
||||
|
||||
@
|
||||
|
||||
There are two events we care about: view the list, and view a detail.
|
||||
They are routed like this:
|
||||
|
||||
<<router>>=
|
||||
routes: {
|
||||
"": "index",
|
||||
"item/:id": "product",
|
||||
},
|
||||
|
||||
@
|
||||
|
||||
Like most Backbone objects, the Router has an initialization feature.
|
||||
I create a new, empty shopping cart and corresponding cart widget,
|
||||
which doesn't render because it's empty. I then create a new
|
||||
[[ProductCollection]] and and corresponding [[ProductListView]].
|
||||
These are all processes that happen immediately.
|
||||
|
||||
What does not happen immediately is the [[fetch()]] of data from the
|
||||
back-end server. For that, I use the jQuery deferred again, because
|
||||
[[fetch()]] ultimately returns the results of [[sync()]], which
|
||||
returns the result of an [[ajax()]] call, which is a deferred.
|
||||
|
||||
<<router>>=
|
||||
initialize: function(data) {
|
||||
this.cart = new ItemCollection();
|
||||
new CartWidget({collection: this.cart});
|
||||
|
||||
this.products = new ProductCollection([], {
|
||||
url: 'data/items.json'});
|
||||
this.views = {
|
||||
'_index': new ProductListView({
|
||||
collection: this.products
|
||||
})
|
||||
};
|
||||
$.when(this.products.fetch({reset: true}))
|
||||
.then(function() { window.location.hash = ''; });
|
||||
return this;
|
||||
},
|
||||
|
||||
@
|
||||
%$
|
||||
|
||||
There are two things to route \textit{to}, but we must also route
|
||||
\textit{from}. Remember that our two major views, the product list
|
||||
and the product detail, inherited from [[\_BaseView]], which has the
|
||||
[[hide()]] and [[show()]] methods. We want to hide all the views,
|
||||
then show the one invoked. First, let's hide every view we know
|
||||
about. [[hide()]] returns either a deferred (if the object is being
|
||||
hidden) or null. The [[_.select()]] call at the end means that this
|
||||
method returns only an array of deferreds.
|
||||
|
||||
<<router>>=
|
||||
hideAllViews: function () {
|
||||
return _.select(
|
||||
_.map(this.views, function(v) { return v.hide(); }),
|
||||
function (t) { return t != null });
|
||||
},
|
||||
|
||||
@
|
||||
|
||||
Showing the product list view is basically hiding everything, then
|
||||
showing the index:
|
||||
|
||||
<<router>>=
|
||||
index: function() {
|
||||
var view = this.views['_index'];
|
||||
$.when(this.hideAllViews()).then(
|
||||
function() { return view.show(); });
|
||||
},
|
||||
|
||||
@
|
||||
%$
|
||||
|
||||
On the other hand, showing the product detail page is a bit trickier.
|
||||
In order to avoid re-rendering all the time, I am going to create a
|
||||
view for every product in which the user shows interest, and keep it
|
||||
around, showing it a second time if the user wants to see it a second
|
||||
time.
|
||||
|
||||
Not that we pass it the [[ItemCollection]] instance. It uses this to
|
||||
create a new item, which (if you recall from our discussion of
|
||||
[[getOrCreateItemForProduct()]]) is automagically put into the
|
||||
collection as needed. Which means all we need to do is update this
|
||||
item and the item collection \textit{changes}, which in turn causes
|
||||
the [[CartWidget]] to update automagically as well.
|
||||
|
||||
<<router>>=
|
||||
product: function(id) {
|
||||
var product, v, view;
|
||||
product = this.products.detect(function(p) { return p.get('id') == (id); })
|
||||
view = ((v = this.views)['item.' + id]) || (v['item.' + id] = (
|
||||
new ProductView({model: product,
|
||||
itemcollection: this.cart}).render()));
|
||||
$.when(this.hideAllViews()).then(
|
||||
function() { view.show(); });
|
||||
}
|
||||
});
|
||||
@
|
||||
%$
|
||||
|
||||
Finally, we need to start the program
|
||||
|
||||
<<initialization>>=
|
||||
$(document).ready(function() {
|
||||
new BackboneStore();
|
||||
Backbone.history.start();
|
||||
});
|
||||
@
|
||||
%$
|
||||
|
||||
\section{The Program}
|
||||
|
||||
Here's the entirety of the program:
|
||||
|
||||
<<store.js>>=
|
||||
(function() {
|
||||
|
||||
<<product models>>
|
||||
|
||||
<<cart models>>
|
||||
|
||||
<<base view>>
|
||||
|
||||
<<product list view>>
|
||||
|
||||
<<product detail view>>
|
||||
|
||||
<<cart widget>>
|
||||
|
||||
<<router>>
|
||||
|
||||
<<initialization>>
|
||||
|
||||
}).call(this);
|
||||
@
|
||||
|
||||
And that's it. Put it all together, and you've got yourself a working
|
||||
Backbone Store.
|
||||
|
||||
This code is available at my github at
|
||||
\nwanchorto{https://github.com/elfsternberg/The-Backbone-Store}{The
|
||||
Backbone Store}.
|
||||
|
||||
\end{document}
|
||||
|
|
@ -0,0 +1,26 @@
|
|||
#!/usr/bin/env node
|
||||
var fs = require('fs');
|
||||
var Inotify = require('inotify').Inotify;
|
||||
|
||||
var spawn = require('child_process').spawn;
|
||||
|
||||
var spew = function(data) {
|
||||
return console.log(data.toString('utf8'));
|
||||
};
|
||||
|
||||
var server = spawn('./node_modules/http-server/bin/http-server', ['./htdocs/']);
|
||||
server.stdout.on('data', spew);
|
||||
|
||||
var monitor = new Inotify();
|
||||
|
||||
var reBuild = function() {
|
||||
var maker = spawn('make', ['store']);
|
||||
return maker.stdout.on('data', spew);
|
||||
};
|
||||
|
||||
monitor.addWatch({
|
||||
path: "./src/backbonestore.nw",
|
||||
watch_for: Inotify.IN_CLOSE_WRITE,
|
||||
callback: reBuild
|
||||
});
|
||||
|
||||
Binary file not shown.
|
|
@ -1,6 +1,6 @@
|
|||
[
|
||||
{
|
||||
"id": "unless",
|
||||
"id": "unless-you-have-been-drinking",
|
||||
"title": "Unless You Have Been Drinking",
|
||||
"artist": "Adventures in Odyssey",
|
||||
"image": "images/AdventuresInOdyssey_t.jpg",
|
||||
|
|
@ -9,7 +9,7 @@
|
|||
"url": "http://www.amazon.com/Door-Religious-Knives/dp/B001FGW0UQ/?tag=quirkey-20"
|
||||
},
|
||||
{
|
||||
"id": "utmost",
|
||||
"id": "leave-to-do-my-utmost",
|
||||
"title": "Leave To Do My Utmost",
|
||||
"artist": "American Attorneys",
|
||||
"image": "images/AmericanAttorneys_t.jpg",
|
||||
|
|
@ -18,7 +18,7 @@
|
|||
"url": "http://www.amazon.com/gp/product/B002GNOMJE?ie=UTF8&tag=quirkeycom-20&linkCode=as2&camp=1789&creative=390957&creativeASIN=B002GNOMJE"
|
||||
},
|
||||
{
|
||||
"id": "encircled",
|
||||
"id": "the-dead-sleep-encircled-by-the-living",
|
||||
"title": "The Dead Sleep Encircled by The Living",
|
||||
"artist": "British Civil Light Transport",
|
||||
"image": "images/BritishCivilLightTransport_t.jpg",
|
||||
|
|
@ -27,7 +27,7 @@
|
|||
"url": "http://www.amazon.com/Bitte-Orca-Dirty-Projectors/dp/B0026T4RTI/ref=pd_sim_m_12?tag=quirkey-20"
|
||||
},
|
||||
{
|
||||
"id": "assimilation",
|
||||
"id": "periods-of-mental-assimilation",
|
||||
"title": "Periods of Mental Assimilation",
|
||||
"artist": "Grigory Szondy",
|
||||
"image": "images/PeriodsofMentalAssimilation_t.jpg",
|
||||
|
|
@ -36,7 +36,7 @@
|
|||
"url": "http://www.amazon.com/Pains-Being-Pure-Heart/dp/B001LGXIDS/ref=pd_sim_m_44?tag=quirkey-20"
|
||||
},
|
||||
{
|
||||
"id": "bankruptcy",
|
||||
"id": "keenly-developed-moral-bankruptcy",
|
||||
"title": "Keenly Developed Moral Bankruptcy",
|
||||
"artist": "Stealth Monkey Virus",
|
||||
"image": "images/StealthMonkeyVirus_t.jpg",
|
||||
|
|
@ -45,7 +45,7 @@
|
|||
"url": "http://www.amazon.com/Pains-Being-Pure-Heart/dp/B001LGXIDS/ref=pd_sim_m_44?tag=quirkey-20"
|
||||
},
|
||||
{
|
||||
"id": "sparrow",
|
||||
"id": "my-mistresss-sparrow-is-dead",
|
||||
"title": "My Mistress's Sparrow is Dead",
|
||||
"artist": "Sums of Mongolia",
|
||||
"image": "images/SumsofMagnolia_t.jpg",
|
||||
|
Before Width: | Height: | Size: 52 KiB After Width: | Height: | Size: 52 KiB |
|
Before Width: | Height: | Size: 18 KiB After Width: | Height: | Size: 18 KiB |
|
Before Width: | Height: | Size: 60 KiB After Width: | Height: | Size: 60 KiB |
|
Before Width: | Height: | Size: 21 KiB After Width: | Height: | Size: 21 KiB |
|
Before Width: | Height: | Size: 75 KiB After Width: | Height: | Size: 75 KiB |
|
Before Width: | Height: | Size: 22 KiB After Width: | Height: | Size: 22 KiB |
|
Before Width: | Height: | Size: 77 KiB After Width: | Height: | Size: 77 KiB |
|
Before Width: | Height: | Size: 19 KiB After Width: | Height: | Size: 19 KiB |
|
Before Width: | Height: | Size: 62 KiB After Width: | Height: | Size: 62 KiB |
|
Before Width: | Height: | Size: 18 KiB After Width: | Height: | Size: 18 KiB |
|
Before Width: | Height: | Size: 47 KiB After Width: | Height: | Size: 47 KiB |
|
Before Width: | Height: | Size: 7.1 KiB After Width: | Height: | Size: 7.1 KiB |
|
Before Width: | Height: | Size: 56 KiB After Width: | Height: | Size: 56 KiB |
|
Before Width: | Height: | Size: 18 KiB After Width: | Height: | Size: 18 KiB |
|
|
@ -0,0 +1,75 @@
|
|||
<!DOCTYPE html>
|
||||
<html xmlns="http://www.w3.org/1999/xhtml">
|
||||
<head>
|
||||
<title>The Backbone Store</title>
|
||||
<link charset="utf-8" href="jsonstore.css" rel="stylesheet" type="text/css">
|
||||
<script id="store_index_template" type="text/x-underscore-tmplate">
|
||||
<h1>Product Catalog</h1>
|
||||
<ul>
|
||||
<% for(i=0,l=products.length;i<l;++i) { p = products[i]; %>
|
||||
<li class="item">
|
||||
<div class="item-image">
|
||||
<a href="#item/<%= p.id %>">
|
||||
<img alt="<%= p.title %>" src="<%= p.image %>">
|
||||
</a>
|
||||
</div>
|
||||
<div class="item-artist"><%= p.artist %></div>
|
||||
<div class="item-title"><%= p.title %></div>
|
||||
<div class="item-price">$<%= p.price %></div>
|
||||
</li>
|
||||
<% } %>
|
||||
</ul>
|
||||
</script>
|
||||
|
||||
<script id="store_item_template" type="text/x-underscore-template">
|
||||
<div class="item-detail">
|
||||
<div class="item-image">
|
||||
<img alt="<%= title %>" src="<%= large_image %>">
|
||||
</div>
|
||||
<div class="item-info">
|
||||
<div class="item-artist"><%= artist %></div>
|
||||
<div class="item-title"><%= title %></div>
|
||||
<div class="item-price">$<%= price %></div>
|
||||
<div class="item-form"></div>
|
||||
<form action="#/cart" method="post">
|
||||
<p>
|
||||
<label>Quantity:</label>
|
||||
<input class="uqf" name="quantity" size="2" type="text" value="1">
|
||||
</p>
|
||||
<p>
|
||||
<input class="uq" type="submit" value="Add to Cart">
|
||||
</p>
|
||||
</form>
|
||||
<div class="item-link">
|
||||
<a href="<%= url %>">Buy this item on Amazon</a>
|
||||
</div>
|
||||
<div class="back-link">
|
||||
<a href="#">« Back to Items</a>
|
||||
</div>
|
||||
</div>
|
||||
</div>
|
||||
</script>
|
||||
|
||||
<script id="store_cart_template" type="text/x-underscore-template">
|
||||
<p>Items: <%= count %> ($<%= cost %>)</p>
|
||||
</script>
|
||||
|
||||
</head>
|
||||
</head>
|
||||
<body>
|
||||
<div id="container">
|
||||
<div id="header">
|
||||
<h1>
|
||||
The Backbone Store
|
||||
</h1>
|
||||
<div class="cart-info"></div>
|
||||
</div>
|
||||
<div id="main"></div>
|
||||
</div>
|
||||
<script src="lib/jquery.js" type="text/javascript"></script>
|
||||
<script src="lib/underscore.js" type="text/javascript"></script>
|
||||
<script src="lib/backbone.js" type="text/javascript"></script>
|
||||
<script src="store.js" type="text/javascript"></script>
|
||||
</body>
|
||||
</html>
|
||||
|
||||
|
|
@ -0,0 +1,91 @@
|
|||
body {
|
||||
font-family: "Lucida Grande", Lucida, Helvetica, Arial, sans-serif;
|
||||
background: #fff;
|
||||
color: #333;
|
||||
margin: 0px;
|
||||
padding: 0px;
|
||||
}
|
||||
#main {
|
||||
position: relative;
|
||||
}
|
||||
#header {
|
||||
background: #999;
|
||||
background: -webkit-gradient(linear, left top, left bottom, from(#adadad), to(#7a7a7a));
|
||||
background: -moz-linear-gradient(top, #adadad, #7a7a7a);
|
||||
margin: 0px;
|
||||
padding: 20px;
|
||||
border-bottom: 1px solid #ccc;
|
||||
}
|
||||
#header h1 {
|
||||
font-family: Inconsolata, Monaco, Courier, mono;
|
||||
color: #fff;
|
||||
margin: 0px;
|
||||
}
|
||||
#header .cart-info {
|
||||
position: absolute;
|
||||
top: 0px;
|
||||
right: 0px;
|
||||
text-align: right;
|
||||
padding: 10px;
|
||||
background: #555;
|
||||
background: -webkit-gradient(linear, left top, left bottom, from(#777), to(#444));
|
||||
background: -moz-linear-gradient(top, #777, #444);
|
||||
color: #fff;
|
||||
font-size: 12px;
|
||||
font-weight: bold;
|
||||
}
|
||||
img {
|
||||
border: 0;
|
||||
}
|
||||
.productitemview {
|
||||
position: absolute;
|
||||
top: 0;
|
||||
left: 0;
|
||||
}
|
||||
#productlistview {
|
||||
position: absolute;
|
||||
top: 0;
|
||||
left: 0;
|
||||
}
|
||||
#productlistview ul {
|
||||
list-style: none;
|
||||
}
|
||||
.item {
|
||||
float: left;
|
||||
width: 250px;
|
||||
margin-right: 10px;
|
||||
margin-bottom: 10px;
|
||||
padding: 5px;
|
||||
-moz-border-radius-topleft: 5px;
|
||||
-moz-border-radius-topright: 5px;
|
||||
-moz-border-radius-bottomleft: 5px;
|
||||
-moz-border-radius-bottomright: 5px;
|
||||
-webkit-border-bottom-right-radius: 5px;
|
||||
-webkit-border-top-left-radius: 5px;
|
||||
-webkit-border-top-right-radius: 5px;
|
||||
-webkit-border-bottom-left-radius: 5px;
|
||||
border-bottom-right-radius: 5px;
|
||||
border-top-left-radius: 5px;
|
||||
border-top-right-radius: 5px;
|
||||
border-bottom-left-radius: 5px;
|
||||
border: 1px solid #ccc;
|
||||
text-align: center;
|
||||
font-size: 12px;
|
||||
}
|
||||
.item-title {
|
||||
font-weight: bold;
|
||||
}
|
||||
.item-artist {
|
||||
font-weight: bold;
|
||||
font-size: 14px;
|
||||
}
|
||||
.item-detail {
|
||||
margin: 10px 0 0 10px;
|
||||
}
|
||||
.item-detail .item-image {
|
||||
float: left;
|
||||
margin-right: 10px;
|
||||
}
|
||||
.item-detail .item-info {
|
||||
padding: 100px 10px 0px 10px;
|
||||
}
|
||||
|
|
@ -0,0 +1,227 @@
|
|||
var Product = Backbone.Model.extend({});
|
||||
|
||||
var Item = Backbone.Model.extend({
|
||||
update: function(amount) {
|
||||
if (amount === this.get('quantity')) {
|
||||
return this;
|
||||
}
|
||||
this.set({quantity: amount}, {silent: true});
|
||||
this.collection.trigger('update', this);
|
||||
return this;
|
||||
},
|
||||
|
||||
price: function() {
|
||||
return this.get('product').get('price') * this.get('quantity');
|
||||
}
|
||||
});
|
||||
|
||||
|
||||
var ProductCollection = Backbone.Collection.extend({
|
||||
model: Product,
|
||||
initialize: function(models, options) {
|
||||
this.url = options.url;
|
||||
},
|
||||
|
||||
comparator: function(item) {
|
||||
return item.get('title');
|
||||
}
|
||||
});
|
||||
|
||||
|
||||
var ItemCollection = Backbone.Collection.extend({
|
||||
model: Item,
|
||||
|
||||
updateItemForProduct: function(product, amount) {
|
||||
amount = amount != null ? amount : 0;
|
||||
var pid = product.get('id');
|
||||
var item = this.detect(function(obj) {
|
||||
return obj.get('product').get('id') === pid;
|
||||
});
|
||||
if (item) {
|
||||
item.update(amount);
|
||||
return item;
|
||||
}
|
||||
return this.add({
|
||||
product: product,
|
||||
quantity: amount
|
||||
});
|
||||
},
|
||||
|
||||
getTotalCount: function() {
|
||||
var addup = function(memo, obj) {
|
||||
return memo + obj.get('quantity');
|
||||
};
|
||||
return this.reduce(addup, 0);
|
||||
},
|
||||
|
||||
getTotalCost: function() {
|
||||
var addup = function(memo, obj) {
|
||||
return memo + obj.price();
|
||||
};
|
||||
return this.reduce(addup, 0);
|
||||
}
|
||||
});
|
||||
|
||||
|
||||
var BaseView = Backbone.View.extend({
|
||||
parent: $('#main'),
|
||||
className: 'viewport',
|
||||
|
||||
initialize: function(options) {
|
||||
Backbone.View.prototype.initialize.apply(this, arguments);
|
||||
this.$el.hide();
|
||||
this.parent.append(this.el);
|
||||
},
|
||||
|
||||
hide: function() {
|
||||
var dfd = $.Deferred();
|
||||
if (!this.$el.is(':visible')) {
|
||||
return dfd.resolve();
|
||||
}
|
||||
this.$el.fadeOut('fast', function() {
|
||||
return dfd.resolve();
|
||||
});
|
||||
return dfd.promise();
|
||||
},
|
||||
|
||||
show: function() {
|
||||
var dfd = $.Deferred();
|
||||
if (this.$el.is(':visible')) {
|
||||
return dfd.resolve();
|
||||
}
|
||||
this.$el.fadeIn('fast', function() {
|
||||
return dfd.resolve();
|
||||
});
|
||||
return dfd.promise();
|
||||
}
|
||||
});
|
||||
|
||||
|
||||
var ProductListView = BaseView.extend({
|
||||
id: 'productlistview',
|
||||
template: _.template($("#store_index_template").html()),
|
||||
|
||||
initialize: function(options) {
|
||||
BaseView.prototype.initialize.apply(this, arguments);
|
||||
this.collection.bind('reset', this.render.bind(this));
|
||||
},
|
||||
|
||||
render: function() {
|
||||
this.$el.html(this.template({
|
||||
'products': this.collection.toJSON()
|
||||
}));
|
||||
return this;
|
||||
}
|
||||
});
|
||||
|
||||
|
||||
var ProductView = BaseView.extend({
|
||||
className: 'productitemview',
|
||||
template: _.template($("#store_item_template").html()),
|
||||
|
||||
initialize: function(options) {
|
||||
BaseView.prototype.initialize.apply(this, [options]);
|
||||
this.itemcollection = options.itemcollection;
|
||||
},
|
||||
|
||||
events: {
|
||||
"keypress .uqf" : "updateOnEnter",
|
||||
"click .uq" : "update"
|
||||
},
|
||||
|
||||
update: function(e) {
|
||||
e.preventDefault();
|
||||
return this.itemcollection.updateItemForProduct(this.model, parseInt(this.$('.uqf').val()));
|
||||
},
|
||||
|
||||
updateOnEnter: function(e) {
|
||||
if (e.keyCode === 13) {
|
||||
this.update(e);
|
||||
}
|
||||
},
|
||||
|
||||
render: function() {
|
||||
this.$el.html(this.template(this.model.toJSON()));
|
||||
return this;
|
||||
}
|
||||
});
|
||||
|
||||
|
||||
var CartWidget = Backbone.View.extend({
|
||||
el: $('.cart-info'),
|
||||
template: _.template($('#store_cart_template').html()),
|
||||
|
||||
initialize: function() {
|
||||
Backbone.View.prototype.initialize.apply(this, arguments);
|
||||
this.collection.bind('update', this.render.bind(this));
|
||||
},
|
||||
|
||||
render: function() {
|
||||
var tel = this.$el.html(this.template({
|
||||
'count': this.collection.getTotalCount(),
|
||||
'cost': this.collection.getTotalCost()
|
||||
}));
|
||||
tel.animate({ paddingTop: '30px' }).animate({ paddingTop: '10px' });
|
||||
return this;
|
||||
}
|
||||
});
|
||||
|
||||
|
||||
var BackboneStore = Backbone.Router.extend({
|
||||
views: {},
|
||||
products: null,
|
||||
cart: null,
|
||||
|
||||
routes: {
|
||||
"": "index",
|
||||
"item/:id": "product"
|
||||
},
|
||||
|
||||
initialize: function(data) {
|
||||
Backbone.Router.prototype.initialize.apply(this, arguments);
|
||||
this.cart = new ItemCollection();
|
||||
new CartWidget({ collection: this.cart });
|
||||
this.products = new ProductCollection([], { url: 'data/items.json' });
|
||||
this.views = {
|
||||
'_index': new ProductListView({ collection: this.products })
|
||||
};
|
||||
$.when(this.products.fetch({ reset: true })).then(function() {
|
||||
return window.location.hash = '';
|
||||
});
|
||||
},
|
||||
|
||||
hideAllViews: function() {
|
||||
return _.filter(_.map(this.views, function(v) { return v.hide(); }),
|
||||
function(t) { return t !== null; });
|
||||
},
|
||||
|
||||
index: function() {
|
||||
var view = this.views['_index'];
|
||||
return $.when.apply($, this.hideAllViews()).then(function() {
|
||||
return view.show();
|
||||
});
|
||||
},
|
||||
|
||||
product: function(id) {
|
||||
var view = this.views[id];
|
||||
if (!view) {
|
||||
var product = this.products.detect(function(p) {
|
||||
return p.get('id') === id;
|
||||
});
|
||||
view = this.views[id] = new ProductView({
|
||||
model: product,
|
||||
itemcollection: this.cart
|
||||
}).render();
|
||||
}
|
||||
return $.when(this.hideAllViews()).then(function() {
|
||||
return view.show();
|
||||
});
|
||||
}
|
||||
});
|
||||
|
||||
|
||||
$(document).ready(function() {
|
||||
new BackboneStore();
|
||||
return Backbone.history.start();
|
||||
});
|
||||
|
||||
75
index.html
75
index.html
|
|
@ -1,75 +0,0 @@
|
|||
<!DOCTYPE html>
|
||||
<html xmlns="http://www.w3.org/1999/xhtml">
|
||||
<head>
|
||||
<title>
|
||||
The Backbone Store
|
||||
</title>
|
||||
<link rel="stylesheet" href="jsonstore.css" type="text/css">
|
||||
<script id="store_index_template" type="text/x-underscore-tmplate">
|
||||
<h1>Product Catalog</h1>
|
||||
<ul>
|
||||
<% for(i=0,l=products.length;i<l;++i) { p = products[i]; %>
|
||||
<li class="item">
|
||||
<div class="item-image">
|
||||
<a href="#item/<%= p.id %>">
|
||||
<img alt="<%= p.title %>" src="<%= p.image %>" />
|
||||
</a>
|
||||
</div>
|
||||
<div class="item-artist"><%= p.artist %></div>
|
||||
<div class="item-title"><%= p.title %></div>
|
||||
<div class="item-price">$<%= p.price %></div>
|
||||
</li>
|
||||
<% } %>
|
||||
</ul>
|
||||
</script>
|
||||
<script id="store_item_template" type="text/x-underscore-template">
|
||||
<div class="item-detail">
|
||||
<div class="item-image">
|
||||
<img alt="<%= title %>" src="<%= large_image %>" />
|
||||
</div>
|
||||
</div>
|
||||
<div class="item-info">
|
||||
<div class="item-artist"><%= artist %></div>
|
||||
<div class="item-title"><%= title %></div>
|
||||
<div class="item-price">$<%= price %></div>
|
||||
<form action="#/cart" method="post">
|
||||
<p>
|
||||
<label>Quantity:</label>
|
||||
<input class="uqf" name="quantity" size="2" type="text" value="1" />
|
||||
</p>
|
||||
<p>
|
||||
<input class="uq" type="submit" value="Add to Cart" />
|
||||
</p>
|
||||
</form>
|
||||
<div class="item-link">
|
||||
<a href="<%= url %>">Buy this item on Amazon</a>
|
||||
</div>
|
||||
<div class="back-link">
|
||||
<a href="#">« Back to Items</a>
|
||||
</div>
|
||||
</div>
|
||||
</script>
|
||||
<script id="store_cart_template" type="text/x-underscore-template">
|
||||
<p>Items: <%= count %> ($<%= cost %>)</p>
|
||||
</script>
|
||||
|
||||
</head>
|
||||
<body>
|
||||
<div id="container">
|
||||
<div id="header">
|
||||
<h1>
|
||||
The Backbone Store
|
||||
</h1>
|
||||
|
||||
<div class="cart-info">
|
||||
</div>
|
||||
</div>
|
||||
|
||||
<div id="main"> </div>
|
||||
</div>
|
||||
<script src="jquery-1.6.2.min.js" type="text/javascript"></script>
|
||||
<script src="underscore.js" type="text/javascript"></script>
|
||||
<script src="backbone.js" type="text/javascript"></script>
|
||||
<script src="store.js" type="text/javascript"></script>
|
||||
</body>
|
||||
</html>
|
||||
File diff suppressed because one or more lines are too long
|
|
@ -1,63 +0,0 @@
|
|||
/******************************************************
|
||||
* json store *
|
||||
\*****************************************************/
|
||||
body {
|
||||
font-family: "Lucida Grande", Lucida, Helvetica, Arial, sans-serif;
|
||||
background: #FFF;
|
||||
color: #333;
|
||||
margin: 0px;
|
||||
padding: 0px;
|
||||
}
|
||||
|
||||
#header {
|
||||
background: #C97E41;
|
||||
margin: 0px;
|
||||
padding: 20px;
|
||||
}
|
||||
#header h1 {
|
||||
font-family: Inconsolata, Monaco, Courier, mono;
|
||||
color: #FFF;
|
||||
margin: 0px;
|
||||
}
|
||||
#header .cart-info {
|
||||
position: absolute;
|
||||
top: 0px;
|
||||
right: 0px;
|
||||
text-align: right;
|
||||
padding: 10px;
|
||||
background: #714625;
|
||||
color: #FFF;
|
||||
font-size: 12px;
|
||||
font-weight: bold;
|
||||
}
|
||||
img {
|
||||
border: 0;
|
||||
}
|
||||
#productlistview ul {
|
||||
list-style: none;
|
||||
}
|
||||
|
||||
.item {
|
||||
display: border;
|
||||
float:left;
|
||||
width: 250px;
|
||||
margin-right: 10px;
|
||||
margin-bottom: 10px;
|
||||
padding: 10px;
|
||||
border: 1px solid #ccc;
|
||||
text-align:center;
|
||||
font-size: 12px;
|
||||
}
|
||||
.item-title {
|
||||
font-weight: bold;
|
||||
}
|
||||
.item-artist {
|
||||
font-weight: bold;
|
||||
font-size: 14px;
|
||||
}
|
||||
.item-detail .item-image {
|
||||
float:left;
|
||||
}
|
||||
.item-detail .item-info {
|
||||
padding: 100px 10px 0px 10px;
|
||||
}
|
||||
|
|
@ -0,0 +1,33 @@
|
|||
{
|
||||
"name": "the-backbone-store",
|
||||
"version": "3.0.1",
|
||||
"description": "A comprehensive (one hopes) tutorial on a simple development platform for Backbone.",
|
||||
"main": "htdocs/index.html",
|
||||
"dependencies": {
|
||||
"http-server": "^0.9.0"
|
||||
},
|
||||
"devDependencies": {
|
||||
"inotify": "^1.4.0",
|
||||
"bower": "^1.7.0"
|
||||
},
|
||||
"scripts": {
|
||||
"test": "make serve"
|
||||
},
|
||||
"repository": {
|
||||
"type": "git",
|
||||
"url": "git+https://github.com/elfsternberg/The-Backbone-Store.git"
|
||||
},
|
||||
"keywords": [
|
||||
"backbone",
|
||||
"javascript",
|
||||
"makefiles",
|
||||
"node",
|
||||
"tutorial"
|
||||
],
|
||||
"author": "Kenneth M. \"Elf\" Sternberg <elf.sternberg@gmail.com>",
|
||||
"license": "BSD-2-Clause",
|
||||
"bugs": {
|
||||
"url": "https://github.com/elfsternberg/The-Backbone-Store/issues"
|
||||
},
|
||||
"homepage": "https://github.com/elfsternberg/The-Backbone-Store#readme"
|
||||
}
|
||||
|
|
@ -0,0 +1,839 @@
|
|||
% -*- Mode: poly-noweb+javascript -*-
|
||||
\documentclass{article}
|
||||
\usepackage{noweb}
|
||||
\usepackage[T1]{fontenc}
|
||||
\usepackage{hyperref}
|
||||
\usepackage{fontspec, xunicode, xltxtra}
|
||||
\setromanfont{Georgia}
|
||||
\begin{document}
|
||||
|
||||
% Generate code and documentation with:
|
||||
%
|
||||
% noweave -filter l2h -delay -x -html backbonestore.nw | htmltoc > backbonestore.html
|
||||
% notangle -Rstore.js backbonestore.nw > store.js
|
||||
% notangle -Rindex.html backbonestore.nw > index.html
|
||||
|
||||
\section{Introduction}
|
||||
|
||||
This is version 3.0 of \textbf{The Backbone Store}, a brief tutorial on
|
||||
using [[backbone.js]]. The version you are currently reading has been
|
||||
tested with the latest versions of the supporting software as of April,
|
||||
2016.
|
||||
|
||||
\nwanchorto{http://documentcloud.github.com/backbone/}{Backbone.js} is
|
||||
a popular Model-View-Controller (MVC) library that provides a
|
||||
framework for creating data-rich, single-page web applications. It
|
||||
provides (1) a two-layer scheme for separating data from presentation,
|
||||
(2) a means of automatically synchronizing data with a server in a
|
||||
RESTful manner, and (3) a mechanism for making some views bookmarkable
|
||||
and navigable.
|
||||
|
||||
There are a number of other good tutorials for Backbone (See:
|
||||
\nwanchorto{http://www.plexical.com/blog/2010/11/18/backbone-js-tutorial/}{Meta
|
||||
Cloud},
|
||||
\nwanchorto{http://andyet.net/blog/2010/oct/29/building-a-single-page-app-with-backbonejs-undersc/?utm_source=twitterfeed&utm_medium=twitter}{\&Yet's
|
||||
Tutorial},
|
||||
\nwanchorto{http://bennolan.com/2010/11/24/backbone-jquery-demo.html}{Backbone
|
||||
Mobile} (which is written in
|
||||
\nwanchorto{http://jashkenas.github.com/coffee-script/}{Coffee}), and
|
||||
\nwanchorto{http://joshbohde.com/2010/11/25/backbonejs-and-django/}{Backbone
|
||||
and Django}. However, a couple of months ago I was attempting to
|
||||
learn Sammy.js, a library very similar to Backbone, and they had a
|
||||
nifty tutorial called
|
||||
\nwanchorto{http://code.quirkey.com/sammy/tutorials/json_store_part1.html}{The
|
||||
JsonStore}.
|
||||
|
||||
In the spirit of The JSON Store, I present The Backbone Store.
|
||||
|
||||
\subsection{Literate Program}
|
||||
|
||||
A note: this article was written with the
|
||||
\nwanchorto{http://en.wikipedia.org/wiki/Literate_programming}{Literate
|
||||
Programming} toolkit
|
||||
\nwanchorto{http://www.cs.tufts.edu/~nr/noweb/}{Noweb}. Where you see
|
||||
something that looks like $\langle\langle$this$\rangle\rangle$, it's a
|
||||
placeholder for code described elsewhere in the document. Placeholders
|
||||
with an equal sign at the end of them indicate the place where that code
|
||||
is defined. The link (U->) indicates that the code you're seeing is
|
||||
used later in the document, and (<-U) indicates it was used earlier but
|
||||
is being defined here.
|
||||
|
||||
\subsection{Revision}
|
||||
|
||||
This is version 3.0 of \textit{The Backbone Store}. It includes several
|
||||
significant updates, including the use of both NPM and Bower to build
|
||||
the final application.
|
||||
|
||||
\subsection{The Store: What We're Going to Build}
|
||||
|
||||
To demonstrate the basics of Backbone, I'm going to create a simple
|
||||
one-page application, a store for record albums, with two unique views:
|
||||
a list of all products and a product detail view. I will also put a
|
||||
shopping cart widget on the page that shows the user how many products
|
||||
have been has dropped into the cart. I'll use some simple animations to
|
||||
transition between the catalog and the product detail pages.
|
||||
|
||||
\subsection{Models, Collections, and Controllers}
|
||||
|
||||
Backbone's data layer provides two classes, [[Collection]] and
|
||||
[[Model]].
|
||||
|
||||
Every web application has data, often tabular data. Addressing tabular
|
||||
data usually involves three parts: The \textit{table}, \textit{row}, and
|
||||
\textit{column}. In Backbone, these are represented by the
|
||||
[[Collection]], the [[Model]], and the [[attribute]]. The
|
||||
[[Collection]] often has a URL indicating the back-end source of the
|
||||
table; the [[Model]] may have a URL indicating its specific row in the
|
||||
table, as a way of efficiently saving itserlf back to the table.
|
||||
|
||||
To use the Model, you inherit from it using Backbone's own [[.extend()]]
|
||||
class method, adding or replacing methods in the child object as needed.
|
||||
For our purposes, we have two models: [[Product]] represents something
|
||||
we wish to sell, and [[Item]] represents something currently in the
|
||||
customer's shopping cart.
|
||||
|
||||
The Product literally has nothing to modify. It already provides all
|
||||
the methods we need.
|
||||
|
||||
Shopping carts are a little odd; the convention is that [[Item]] is not a
|
||||
single instance of the product, but instead has a reference to the
|
||||
product, and a count of how many the buyer wants. To that end, I am
|
||||
adding two methods that extend Item: [[.update()]], which changes the
|
||||
current quantity, and [[.price()]], which calculates the product's price
|
||||
times the quantity:
|
||||
|
||||
<<models>>=
|
||||
var Product = Backbone.Model.extend({});
|
||||
|
||||
var Item = Backbone.Model.extend({
|
||||
update: function(amount) {
|
||||
if (amount === this.get('quantity')) {
|
||||
return this;
|
||||
}
|
||||
this.set({quantity: amount}, {silent: true});
|
||||
this.collection.trigger('update', this);
|
||||
return this;
|
||||
},
|
||||
|
||||
price: function() {
|
||||
return this.get('product').get('price') * this.get('quantity');
|
||||
}
|
||||
});
|
||||
|
||||
@
|
||||
|
||||
The methods [[.get(item)]] and [[.set(item, value)]] are at the heart of
|
||||
Backbone.Model. They're how you set individual attributes on the object
|
||||
being manipulated. Notice how I can 'get' the product, which is a
|
||||
Backbone.Model, and then 'get' its price. This is called a
|
||||
\textit{chain}, and is fairly common in Javascript.
|
||||
|
||||
The big secret to Backbone is that it supplies an advanced event
|
||||
management toolkit. Changing a model triggers various events, none of
|
||||
which matter here in this context so I silence the event, but then I
|
||||
tell the Item's Backbone.Collection that the Model has changed. For
|
||||
this program, it is the collection as a whole whose value matters,
|
||||
because that collection as a whole represents our shopping cart. Events
|
||||
are the primary way in which Backbone objects interact, so understanding
|
||||
them is key to using Backbone correctly.
|
||||
|
||||
Collections, like Models, are just objects you can (and often must)
|
||||
extend to support your application's needs. Just as a Model has
|
||||
\texttt{.get()} and \texttt{.set()}, a Collection has [[.add(item)]] and
|
||||
[[.remove(id)]] as methods. Collections have a lot more than that.
|
||||
|
||||
Both Models and Collections also have [[.fetch()]] and [[.save()]]. If
|
||||
either has a URL, these methods allow the collection to represent data
|
||||
on the server, and to save that data back to the server. The default
|
||||
method is a simple JSON object representing either a Model's attributes,
|
||||
or a JSON list of the Collection's models' attributes.
|
||||
|
||||
The [[Product.Collection]] will be loading its list of albums via these
|
||||
methods to (in our case) static JSON back-end. Backbone provides a
|
||||
mechanism for fetching JSON (and you can override the [[.parse()]]
|
||||
method to handle XML, CSV, or whatever strikes your fancy); to use the
|
||||
default [[.fetch()]] method, capture and set the Collection's [[.url]]
|
||||
field:
|
||||
|
||||
<<product collection>>=
|
||||
var ProductCollection = Backbone.Collection.extend({
|
||||
model: Product,
|
||||
initialize: function(models, options) {
|
||||
this.url = options.url;
|
||||
},
|
||||
|
||||
comparator: function(product) {
|
||||
return product.get('title');
|
||||
}
|
||||
});
|
||||
|
||||
@
|
||||
|
||||
The [[.model]] attribute tells the [[ProductCollection]] that if
|
||||
[[.add()]] or [[.fetch()]] are called and the contents are plain JSON,
|
||||
a new [[Product]] Model should be initialized with the JSON data and
|
||||
that will be used as a new object for the Collection.
|
||||
|
||||
The [[.comparator()]] method specifies the per-model value by which the
|
||||
Collection should be sorted. Sorting happens automatically whenever the
|
||||
Collection receives an event indicating its contents have been altered.
|
||||
|
||||
The [[ItemCollection]] doesn't have a URL, but we do have several helper
|
||||
methods to add. We don't want to add Items; instead, we want to add
|
||||
products as needed, then update the count as requested. If the product
|
||||
is already in our system, we don't want to create duplicates.
|
||||
|
||||
First, we ensure that if we don't receive an amount, we at least provide
|
||||
a valid \textit{numerical} value to our code. The [[.detect()]] method
|
||||
lets us find an object in our Collection using a function to compare
|
||||
them; it returns the first object that matches.
|
||||
|
||||
If we find the object, we update it and return. If we don't, we create
|
||||
a new one, exploiting the fact that, since we specified the Collection's
|
||||
Model above, it will automatically be created as a Model in the
|
||||
Collection at the end of this call. In either case, we return the new
|
||||
Item to be handled further by the calling code.
|
||||
|
||||
<<cart collection>>=
|
||||
var ItemCollection = Backbone.Collection.extend({
|
||||
model: Item,
|
||||
|
||||
updateItemForProduct: function(product, amount) {
|
||||
amount = amount != null ? amount : 0;
|
||||
var pid = product.get('id');
|
||||
var item = this.detect(function(obj) {
|
||||
return obj.get('product').get('id') === pid;
|
||||
});
|
||||
if (item) {
|
||||
item.update(amount);
|
||||
return item;
|
||||
}
|
||||
return this.add({
|
||||
product: product,
|
||||
quantity: amount
|
||||
});
|
||||
},
|
||||
|
||||
@
|
||||
|
||||
And finally, two methods to add up how many objects are in your cart,
|
||||
and the total price. The first line creates a function to get the
|
||||
number for a single object and add it to a memo. The second line uses
|
||||
the [[.reduce()]] method, which goes through each object in the
|
||||
collection and runs the function, passing the results of each run to the
|
||||
next as the memo.
|
||||
|
||||
<<cart collection>>=
|
||||
getTotalCount: function() {
|
||||
var addup = function(memo, obj) {
|
||||
return memo + obj.get('quantity');
|
||||
};
|
||||
return this.reduce(addup, 0);
|
||||
},
|
||||
|
||||
getTotalCost: function() {
|
||||
var addup = function(memo, obj) {
|
||||
return memo + obj.price();
|
||||
};
|
||||
return this.reduce(addup, 0);
|
||||
}
|
||||
});
|
||||
|
||||
@
|
||||
|
||||
\subsection {Views}
|
||||
|
||||
Backbone Views are simple policy objects. They have a root DOM
|
||||
element, the contents of which they manipulate and to which they
|
||||
listen for events, and a model or collection they represent within
|
||||
that element. Views are not rigid; it's just Javascript and the DOM,
|
||||
and you can hook external events as needed.
|
||||
|
||||
More importantly, if you pass a model or collection to a View, that View
|
||||
becomes sensitive to events \textit{within its model or collection}, and
|
||||
can respond to changes automatically. This way, if you have a rich data
|
||||
ecosystem, when changes to one data item results in a cascade of changes
|
||||
throughout your datasets, the views will receive ``change'' events and
|
||||
can update themselves accordingly.
|
||||
|
||||
In a way, a View can be thought of as two separate but important
|
||||
sub-programs, each based on events. The first listens to events from
|
||||
the DOM, and forwards data-changing events to associated models or
|
||||
collections. The second listens to events from data objects and
|
||||
re-draws the View's contents when the data changes. Keeping these
|
||||
separate in your mind will help you design Backbone applications
|
||||
successfully.
|
||||
|
||||
I will show how this works with the shopping cart widget.
|
||||
|
||||
To achieve the [[fadeIn/fadeOut]] animations and enforce consistency,
|
||||
I'm going to do some basic object-oriented programming. I'm going to
|
||||
create a base class that contains knowledge about the main area into
|
||||
which all views are rendered, and that manages these transitions.
|
||||
|
||||
With this technique, you can do lots of navigation-related tricks: you
|
||||
can highlight where the user is in breadcrumb-style navigation; you
|
||||
can change the class and highlight an entry on a nav bar; you can add
|
||||
and remove tabs from the top of the viewport as needed.
|
||||
|
||||
<<base view>>=
|
||||
var BaseView = Backbone.View.extend({
|
||||
parent: $('#main'),
|
||||
className: 'viewport',
|
||||
|
||||
initialize: function(options) {
|
||||
Backbone.View.prototype.initialize.apply(this, arguments);
|
||||
this.$el.hide();
|
||||
this.parent.append(this.el);
|
||||
},
|
||||
|
||||
@
|
||||
|
||||
The above says that I am creating a class called \texttt{BaseView} and
|
||||
defining two fields. The first, 'parent', will be used by all child
|
||||
views to identify into which DOM object the View root element will be
|
||||
rendered. The second defines a common class we will use for the purpose
|
||||
of identifying these views to jQuery. Backbone automatically creates a
|
||||
new [[DIV]] object with the class 'viewport' when a view constructor is
|
||||
called. It will be our job to attach that [[DIV]] to the DOM. In the
|
||||
HTML, you will see the [[DIV#main]] object where most of the work will
|
||||
be rendered.
|
||||
|
||||
As an alternative, the viewport object may already exist, in which case
|
||||
you just find it with a selector, and the view attaches itself to that
|
||||
DOM object from then on. In older versions of the Backbone Store, we
|
||||
used to assign [[this.el]] to a jQuery-wrapped version of the element;
|
||||
that's no longer necessary, as Backbone provides you with its own
|
||||
version automatically in [[this.$el]].
|
||||
|
||||
The 'parent' field is something I created for my own use, since I intend
|
||||
to have multiple child objects share the same piece of real-estate. The
|
||||
'className' field is something Backbone automatically applies to the
|
||||
generated [[DIV]] at construction time. If you pass in an existing
|
||||
element at construction time for the View to use (which is not an
|
||||
uncommon use case!), Backbone will \textit{not} apply the 'className' to
|
||||
it; you'll have to do that yourself.
|
||||
|
||||
I use the [[initialize]] method above to ensure that the element is
|
||||
rendered, but not visible, and contained within the [[DIV#main]]. Note
|
||||
also that the element is not a sacrosanct object; the Backbone.View is
|
||||
more a collection of standards than a mechanism of enforcement, and so
|
||||
defining it from a raw DOM object or a jQuery object will not break
|
||||
anything.
|
||||
|
||||
Next, we will define the hide and show functions.
|
||||
|
||||
<<base view>>=
|
||||
hide: function() {
|
||||
var dfd = $.Deferred();
|
||||
if (!this.$el.is(':visible')) {
|
||||
return dfd.resolve();
|
||||
}
|
||||
this.$el.fadeOut('fast', function() {
|
||||
return dfd.resolve();
|
||||
});
|
||||
return dfd.promise();
|
||||
},
|
||||
|
||||
show: function() {
|
||||
var dfd = $.Deferred();
|
||||
if (this.$el.is(':visible')) {
|
||||
return dfd.resolve();
|
||||
}
|
||||
this.$el.fadeIn('fast', function() {
|
||||
return dfd.resolve();
|
||||
});
|
||||
return dfd.promise();
|
||||
}
|
||||
});
|
||||
|
||||
@
|
||||
|
||||
\textbf{Deferred} is a feature of jQuery called ``promises''. It is a
|
||||
different mechanism for invoking callbacks by attaching attributes and
|
||||
behavior to the callback function. By using this, we can say thing like
|
||||
``\textit{When} everything is hidden (when every deferred returned from
|
||||
\textbf{hide} has been resolved), \textit{then} show the appropriate
|
||||
viewport.'' Deferreds are incredibly powerful, and this is a small
|
||||
taste of what can be done with them.
|
||||
|
||||
Before we move on, let's take a look at the HTML we're going to use for
|
||||
our one-page application.
|
||||
|
||||
<<index.html>>=
|
||||
<!DOCTYPE html>
|
||||
<html xmlns="http://www.w3.org/1999/xhtml">
|
||||
<head>
|
||||
<title>The Backbone Store</title>
|
||||
<link charset="utf-8" href="jsonstore.css" rel="stylesheet" type="text/css">
|
||||
<<product list template>>
|
||||
<<product detail template>>
|
||||
<<cart template>>
|
||||
</head>
|
||||
</head>
|
||||
<body>
|
||||
<div id="container">
|
||||
<div id="header">
|
||||
<h1>
|
||||
The Backbone Store
|
||||
</h1>
|
||||
<div class="cart-info"></div>
|
||||
</div>
|
||||
<div id="main"></div>
|
||||
</div>
|
||||
<script src="lib/jquery.js" type="text/javascript"></script>
|
||||
<script src="lib/underscore.js" type="text/javascript"></script>
|
||||
<script src="lib/backbone.js" type="text/javascript"></script>
|
||||
<script src="store.js" type="text/javascript"></script>
|
||||
</body>
|
||||
</html>
|
||||
|
||||
@
|
||||
|
||||
It's not much to look at, but already you can see where that
|
||||
[[DIV\#main]] goes, as well as where we are putting our templates. The
|
||||
[[DIV\#main]] will host a number of viewports, only one of which will be
|
||||
visible at any given time.
|
||||
|
||||
Our first view is going to be the product list view, named, well, guess.
|
||||
Or just look down a few lines.
|
||||
|
||||
This gives us a chance to discuss one of the big confusions new Backbone
|
||||
users frequently have: \textit{What is \texttt{render()} for?}. Render
|
||||
is not there to show or hide the view. \texttt{Render()} is there to
|
||||
\textit{change the view when the underlying data changes}. It renders
|
||||
the data into a view. In our functionality, we use the parent class's
|
||||
\texttt{show()} and \texttt{hide()} methods to actually show the view.
|
||||
|
||||
That call to [[.prototype]] is a Javascript idiom for calling a method
|
||||
on the parent object. It is, as far as anyone knows, the only way to
|
||||
invoke a superclass method if it has been redefined in a subclass. It
|
||||
is rather ugly, but useful.
|
||||
|
||||
<<product list view>>=
|
||||
var ProductListView = BaseView.extend({
|
||||
id: 'productlistview',
|
||||
template: _.template($("#store_index_template").html()),
|
||||
|
||||
initialize: function(options) {
|
||||
BaseView.prototype.initialize.apply(this, arguments);
|
||||
this.collection.bind('reset', this.render.bind(this));
|
||||
},
|
||||
|
||||
render: function() {
|
||||
this.$el.html(this.template({
|
||||
'products': this.collection.toJSON()
|
||||
}));
|
||||
return this;
|
||||
}
|
||||
});
|
||||
|
||||
@
|
||||
%$
|
||||
|
||||
That \texttt{\_.template()} method is provided by undescore.js, and is a
|
||||
full-featured, javascript-based templating method. It's not the fastest
|
||||
or the most feature-complete, but it is more than adequate for our
|
||||
purposes and it means we don't have to import another library. It
|
||||
vaguely resembles ERB from Rails, so if you are familiar with that, you
|
||||
should understand this fairly easily. It takes a template and returns a
|
||||
function ready to render the template. What we're saying here is that
|
||||
we want this View to automatically re-render itself every time the given
|
||||
collection changes in a significant way, using the given template, into
|
||||
the given element. That's what this view ``means.''
|
||||
|
||||
There are many different ways of providing templates to Backbone. The
|
||||
most common, especially for small templates, is to just include it as an
|
||||
inline string inside the View. The \textit{least} common, I'm afraid,
|
||||
is the one I'm doing here: using the $<$script$>$ tag with an
|
||||
unusual mime type to include it with the rest of the HTML. I like this
|
||||
method because it means all of my HTML is in one place.
|
||||
|
||||
For much larger programs, those that use features such as
|
||||
\nwanchorto{http://requirejs.org/}{Require.js}, a common technique is to
|
||||
keep the HTML template fragment in its own file and to import it using
|
||||
Require's ``text'' plugin.
|
||||
|
||||
Here is the HTML for our home page's template:
|
||||
|
||||
<<product list template>>=
|
||||
<script id="store_index_template" type="text/x-underscore-tmplate">
|
||||
<h1>Product Catalog</h1>
|
||||
<ul>
|
||||
<% for(i=0,l=products.length;i<l;++i) { p = products[i]; %>
|
||||
<li class="item">
|
||||
<div class="item-image">
|
||||
<a href="#item/<%= p.id %>">
|
||||
<img alt="<%= p.title %>" src="<%= p.image %>">
|
||||
</a>
|
||||
</div>
|
||||
<div class="item-artist"><%= p.artist %></div>
|
||||
<div class="item-title"><%= p.title %></div>
|
||||
<div class="item-price">$<%= p.price %></div>
|
||||
</li>
|
||||
<% } %>
|
||||
</ul>
|
||||
</script>
|
||||
|
||||
@
|
||||
|
||||
One of the most complicated objects in our ecosystem is the product
|
||||
view. It actually does something! The prefix ought to be familiar,
|
||||
but note that we are again using [[\#main]] as our target; we will be
|
||||
showing and hiding the various [[DIV]] objects in [[\#main]] again and
|
||||
again.
|
||||
|
||||
The only trickiness here is twofold: the means by which one calls the
|
||||
method of a parent class from a child class via Backbone's class
|
||||
heirarchy, and keeping track of the ItemCollection object, so we can add
|
||||
and change items as needed.
|
||||
|
||||
<<product detail view>>=
|
||||
var ProductView = BaseView.extend({
|
||||
className: 'productitemview',
|
||||
template: _.template($("#store_item_template").html()),
|
||||
|
||||
initialize: function(options) {
|
||||
BaseView.prototype.initialize.apply(this, [options]);
|
||||
this.itemcollection = options.itemcollection;
|
||||
},
|
||||
|
||||
@
|
||||
%$
|
||||
|
||||
There are certain events in which we're interested: keypresses and
|
||||
clicks on the update button and the quantity form. (Okay, ``UQ''
|
||||
isn't the best for ``update quantity''. I admit that.) Note the
|
||||
peculiar syntax of ``EVENT SELECTOR'': ``methodByName'' for each
|
||||
event.
|
||||
|
||||
Backbone tells us that the only events it can track by itself are
|
||||
those that jQuery's ``delegate'' understands. As of 1.5, that seems
|
||||
to be just about all of them.
|
||||
|
||||
<<product detail view>>=
|
||||
events: {
|
||||
"keypress .uqf" : "updateOnEnter",
|
||||
"click .uq" : "update"
|
||||
},
|
||||
|
||||
@
|
||||
|
||||
And now we will deal with the update. This code ought to be fairly
|
||||
readable: the only specialness is that it's receiving an event, and
|
||||
we're ``silencing'' the call to [[cart.add()]], which means that the
|
||||
cart collection will not publish any events. There are only events
|
||||
when the item has more than zero, and that gets called on
|
||||
[[cart_item.update()]].
|
||||
|
||||
In the original tutorial, this code had a lot of responsibility for
|
||||
managing the shopping cart, looking into it and seeing if it had an
|
||||
item for this product, and there was lots of accessing the model to
|
||||
get its id and so forth. All of that has been put into the shopping
|
||||
cart model, which is where it belongs: \textit{knowledge about items
|
||||
and each item's relationship to its collection belongs in the
|
||||
collection}.
|
||||
|
||||
Look closely at the [[update()]] method. The reference [[this.$]] is a
|
||||
special Backbone object that limits selectors to objects inside the
|
||||
element of the view. Without it, jQuery would have found the first
|
||||
input field of class 'uqf' in the DOM, not the one for this specific
|
||||
view. [[this.$('.uqf')]] is shorthand for [[$('uqf', this.el)]], and helps
|
||||
clarify what it is you're looking for.
|
||||
|
||||
<<product detail view>>=
|
||||
update: function(e) {
|
||||
e.preventDefault();
|
||||
return this.itemcollection.updateItemForProduct(this.model, parseInt(this.$('.uqf').val()));
|
||||
},
|
||||
|
||||
updateOnEnter: function(e) {
|
||||
if (e.keyCode === 13) {
|
||||
this.update(e);
|
||||
}
|
||||
},
|
||||
|
||||
@
|
||||
|
||||
The render is straightforward:
|
||||
|
||||
<<product detail view>>=
|
||||
render: function() {
|
||||
this.$el.html(this.template(this.model.toJSON()));
|
||||
return this;
|
||||
}
|
||||
});
|
||||
|
||||
@
|
||||
|
||||
The product detail template is fairly straightforward. There is no
|
||||
[[underscore]] magic because there are no loops.
|
||||
|
||||
<<product detail template>>=
|
||||
<script id="store_item_template" type="text/x-underscore-template">
|
||||
<div class="item-detail">
|
||||
<div class="item-image">
|
||||
<img alt="<%= title %>" src="<%= large_image %>">
|
||||
</div>
|
||||
<div class="item-info">
|
||||
<div class="item-artist"><%= artist %></div>
|
||||
<div class="item-title"><%= title %></div>
|
||||
<div class="item-price">$<%= price %></div>
|
||||
<div class="item-form"></div>
|
||||
<form action="#/cart" method="post">
|
||||
<p>
|
||||
<label>Quantity:</label>
|
||||
<input class="uqf" name="quantity" size="2" type="text" value="1">
|
||||
</p>
|
||||
<p>
|
||||
<input class="uq" type="submit" value="Add to Cart">
|
||||
</p>
|
||||
</form>
|
||||
<div class="item-link">
|
||||
<a href="<%= url %>">Buy this item on Amazon</a>
|
||||
</div>
|
||||
<div class="back-link">
|
||||
<a href="#">« Back to Items</a>
|
||||
</div>
|
||||
</div>
|
||||
</div>
|
||||
</script>
|
||||
|
||||
@
|
||||
|
||||
So, let's talk about that shopping cart thing. We've been making the
|
||||
point that when it changes, when you call [[item.update]] within the
|
||||
product detail view, any corresponding subscribing views sholud
|
||||
automatically update.
|
||||
|
||||
<<cart widget>>=
|
||||
var CartWidget = Backbone.View.extend({
|
||||
el: $('.cart-info'),
|
||||
template: _.template($('#store_cart_template').html()),
|
||||
|
||||
initialize: function() {
|
||||
Backbone.View.prototype.initialize.apply(this, arguments);
|
||||
this.collection.bind('update', this.render.bind(this));
|
||||
},
|
||||
|
||||
@
|
||||
%$
|
||||
|
||||
And there is the major magic. CartWidget will be initialized with the
|
||||
ItemCollection; when there is any change in the collection, the widget
|
||||
will receive the 'change' event, which will automatically trigger the
|
||||
call to the widget's [[render()]] method.
|
||||
|
||||
The render method will refill that widget's HTML with a re-rendered
|
||||
template with the new count and cost, and then wiggle it a little to
|
||||
show that it did changed:
|
||||
|
||||
<<cart widget>>=
|
||||
render: function() {
|
||||
var tel = this.$el.html(this.template({
|
||||
'count': this.collection.getTotalCount(),
|
||||
'cost': this.collection.getTotalCost()
|
||||
}));
|
||||
tel.animate({ paddingTop: '30px' }).animate({ paddingTop: '10px' });
|
||||
return this;
|
||||
}
|
||||
});
|
||||
|
||||
@
|
||||
|
||||
You may have noticed that every render ends in [[return this]]. There's
|
||||
a reason for that. Render is supposed to be pure statement: it's not
|
||||
supposed to calculate anything, nor is it supposed to mutate anything on
|
||||
the Javascript side. It can and frequently does, but that's beside the
|
||||
point. By returning [[this]], we can then call something immediately
|
||||
afterward.
|
||||
|
||||
For example, let's say you have a pop-up dialog. It starts life
|
||||
hidden. You need to update the dialog, then show it:
|
||||
|
||||
<<example>>=
|
||||
myDialog.render().show();
|
||||
|
||||
@
|
||||
|
||||
Because what render() return is [[this]], this code works as expected.
|
||||
That's how you do chaining in HTML/Javascript.
|
||||
|
||||
Back to our code. The HTML for the Cart widget template is dead simple:
|
||||
|
||||
<<cart template>>=
|
||||
<script id="store_cart_template" type="text/x-underscore-template">
|
||||
<p>Items: <%= count %> ($<%= cost %>)</p>
|
||||
</script>
|
||||
|
||||
@
|
||||
%$
|
||||
|
||||
Lastly, there is the [[Router]]. In Backbone, the Router is a
|
||||
specialized View for invoking other views. It listens for one
|
||||
specific event: when the [[window.location.hash]] object, the part of
|
||||
the URL after the hash symbol, changes. When the hash changes, the
|
||||
Router invokes an event handler. The Router, since its purpose is to
|
||||
control the major components of the one-page display, is also a good
|
||||
place to keep all the major components of the sytem. We'll keep track
|
||||
of the [[Views]], the [[ProductCollection]], and the
|
||||
[[ItemCollection]].
|
||||
|
||||
<<router>>=
|
||||
var BackboneStore = Backbone.Router.extend({
|
||||
views: {},
|
||||
products: null,
|
||||
cart: null,
|
||||
|
||||
@
|
||||
|
||||
There are two events we care about: view the list, and view a detail.
|
||||
They are routed like this:
|
||||
|
||||
<<router>>=
|
||||
routes: {
|
||||
"": "index",
|
||||
"item/:id": "product"
|
||||
},
|
||||
|
||||
@
|
||||
|
||||
Like most Backbone objects, the Router has an initialization feature.
|
||||
I create a new, empty shopping cart and corresponding cart widget,
|
||||
which doesn't render because it's empty. I then create a new
|
||||
[[ProductCollection]] and and corresponding [[ProductListView]].
|
||||
These are all processes that happen immediately.
|
||||
|
||||
What does not happen immediately is the [[fetch()]] of data from the
|
||||
back-end server. For that, I use the jQuery deferred again, because
|
||||
[[fetch()]] ultimately returns the results of [[sync()]], which
|
||||
returns the result of an [[ajax()]] call, which is a deferred.
|
||||
|
||||
<<router>>=
|
||||
initialize: function(data) {
|
||||
Backbone.Router.prototype.initialize.apply(this, arguments);
|
||||
this.cart = new ItemCollection();
|
||||
new CartWidget({ collection: this.cart });
|
||||
this.products = new ProductCollection([], { url: 'data/items.json' });
|
||||
this.views = {
|
||||
'_index': new ProductListView({ collection: this.products })
|
||||
};
|
||||
$.when(this.products.fetch({ reset: true })).then(function() {
|
||||
return window.location.hash = '';
|
||||
});
|
||||
},
|
||||
|
||||
@
|
||||
%$
|
||||
|
||||
There are two things to route \textit{to}, but we must also route
|
||||
\textit{from}. Remember that our two major views, the product list
|
||||
and the product detail, inherited from [[\_BaseView]], which has the
|
||||
[[hide()]] and [[show()]] methods. We want to hide all the views,
|
||||
then show the one invoked. First, let's hide every view we know
|
||||
about. [[hide()]] returns either a deferred (if the object is being
|
||||
hidden) or null. The [[_.filter()]] call at the end means that this
|
||||
method returns only an array of deferreds.
|
||||
|
||||
<<router>>=
|
||||
hideAllViews: function() {
|
||||
return _.filter(_.map(this.views, function(v) { return v.hide(); }),
|
||||
function(t) { return t !== null; });
|
||||
},
|
||||
|
||||
@
|
||||
|
||||
Showing the product list view is basically hiding everything, then
|
||||
showing the index. The function [[$$.when]] takes arguments of what to
|
||||
wait for; to make it take an array of arguments, you use the
|
||||
[[.apply()]] method.
|
||||
|
||||
<<router>>=
|
||||
index: function() {
|
||||
var view = this.views['_index'];
|
||||
return $.when.apply($, this.hideAllViews()).then(function() {
|
||||
return view.show();
|
||||
});
|
||||
},
|
||||
|
||||
@
|
||||
|
||||
On the other hand, showing the product detail page is a bit trickier.
|
||||
In order to avoid re-rendering all the time, I am going to create a
|
||||
view for every product in which the user shows interest, and keep it
|
||||
around, showing it a second time if the user wants to see it a second
|
||||
time. Note that the view only needs to be rendered \textit{once}, after
|
||||
which we can just hide or show it on request.
|
||||
|
||||
Not that we pass it the [[ItemCollection]] instance. It uses this to
|
||||
create a new item, which (if you recall from our discussion of
|
||||
[[getOrCreateItemForProduct()]]) is automagically put into the
|
||||
collection as needed. Which means all we need to do is update this
|
||||
item and the item collection \textit{changes}, which in turn causes
|
||||
the [[CartWidget]] to update automagically as well.
|
||||
|
||||
<<router>>=
|
||||
product: function(id) {
|
||||
var view = this.views[id];
|
||||
if (!view) {
|
||||
var product = this.products.detect(function(p) {
|
||||
return p.get('id') === id;
|
||||
});
|
||||
view = this.views[id] = new ProductView({
|
||||
model: product,
|
||||
itemcollection: this.cart
|
||||
}).render();
|
||||
}
|
||||
return $.when(this.hideAllViews()).then(function() {
|
||||
return view.show();
|
||||
});
|
||||
}
|
||||
});
|
||||
|
||||
@
|
||||
%$
|
||||
|
||||
Finally, we need to start the program
|
||||
|
||||
<<initialization>>=
|
||||
$(document).ready(function() {
|
||||
new BackboneStore();
|
||||
return Backbone.history.start();
|
||||
});
|
||||
|
||||
@
|
||||
%$
|
||||
|
||||
\section{The Program}
|
||||
|
||||
Here's the entirety of the program. Coffeescript provides its own
|
||||
namespace wrapper:
|
||||
|
||||
<<store.js>>=
|
||||
<<models>>
|
||||
|
||||
<<product collection>>
|
||||
|
||||
<<cart collection>>
|
||||
|
||||
<<base view>>
|
||||
|
||||
<<product list view>>
|
||||
|
||||
<<product detail view>>
|
||||
|
||||
<<cart widget>>
|
||||
|
||||
<<router>>
|
||||
|
||||
<<initialization>>
|
||||
@
|
||||
|
||||
And that's it. Put it all together, and you've got yourself a working
|
||||
Backbone Store.
|
||||
|
||||
This code is available at my github at
|
||||
\nwanchorto{https://github.com/elfsternberg/The-Backbone-Store}{The
|
||||
Backbone Store}.
|
||||
|
||||
\end{document}
|
||||
211
store.js
211
store.js
|
|
@ -1,211 +0,0 @@
|
|||
(function() {
|
||||
|
||||
var Product = Backbone.Model.extend({})
|
||||
|
||||
var ProductCollection = Backbone.Collection.extend({
|
||||
model: Product,
|
||||
|
||||
initialize: function(models, options) {
|
||||
this.url = options.url;
|
||||
},
|
||||
|
||||
comparator: function(item) {
|
||||
return item.get('title');
|
||||
}
|
||||
});
|
||||
|
||||
var Item = Backbone.Model.extend({
|
||||
update: function(amount) {
|
||||
this.set({'quantity': amount}, {silent: true});
|
||||
this.collection.trigger('change', this);
|
||||
},
|
||||
price: function() {
|
||||
console.log(this.get('product').get('title'), this.get('quantity'));
|
||||
return this.get('product').get('price') * this.get('quantity');
|
||||
}
|
||||
});
|
||||
|
||||
var ItemCollection = Backbone.Collection.extend({
|
||||
model: Item,
|
||||
|
||||
getOrCreateItemForProduct: function(product) {
|
||||
var i,
|
||||
pid = product.get('id'),
|
||||
o = this.detect(function(obj) {
|
||||
return (obj.get('product').get('id') == pid);
|
||||
});
|
||||
if (o) {
|
||||
return o;
|
||||
}
|
||||
i = new Item({'product': product, 'quantity': 0})
|
||||
this.add(i, {silent: true})
|
||||
return i;
|
||||
},
|
||||
|
||||
getTotalCount: function() {
|
||||
return this.reduce(function(memo, obj) {
|
||||
return obj.get('quantity') + memo; }, 0);
|
||||
},
|
||||
|
||||
getTotalCost: function() {
|
||||
return this.reduce(function(memo, obj) {
|
||||
return obj.price() + memo; }, 0);
|
||||
}
|
||||
});
|
||||
|
||||
|
||||
var _BaseView = Backbone.View.extend({
|
||||
parent: $('#main'),
|
||||
className: 'viewport',
|
||||
|
||||
initialize: function() {
|
||||
this.el = $(this.el);
|
||||
this.el.hide();
|
||||
this.parent.append(this.el);
|
||||
return this;
|
||||
},
|
||||
|
||||
hide: function() {
|
||||
if (this.el.is(":visible") === false) {
|
||||
return null;
|
||||
}
|
||||
promise = $.Deferred(_.bind(function(dfd) {
|
||||
this.el.fadeOut('fast', dfd.resolve)}, this));
|
||||
return promise.promise();
|
||||
},
|
||||
|
||||
show: function() {
|
||||
if (this.el.is(':visible')) {
|
||||
return;
|
||||
}
|
||||
promise = $.Deferred(_.bind(function(dfd) {
|
||||
this.el.fadeIn('fast', dfd.resolve) }, this))
|
||||
return promise.promise();
|
||||
}
|
||||
});
|
||||
|
||||
|
||||
var ProductListView = _BaseView.extend({
|
||||
id: 'productlistview',
|
||||
template: $("#store_index_template").html(),
|
||||
|
||||
initialize: function(options) {
|
||||
this.constructor.__super__.initialize.apply(this, [options])
|
||||
this.collection.bind('reset', _.bind(this.render, this));
|
||||
},
|
||||
|
||||
render: function() {
|
||||
this.el.html(_.template(this.template,
|
||||
{'products': this.collection.toJSON()}))
|
||||
return this;
|
||||
}
|
||||
});
|
||||
|
||||
|
||||
var ProductView = _BaseView.extend({
|
||||
id: 'productitemview',
|
||||
template: $("#store_item_template").html(),
|
||||
initialize: function(options) {
|
||||
this.constructor.__super__.initialize.apply(this, [options])
|
||||
this.itemcollection = options.itemcollection;
|
||||
this.item = this.itemcollection.getOrCreateItemForProduct(this.model);
|
||||
return this;
|
||||
},
|
||||
|
||||
events: {
|
||||
"keypress .uqf" : "updateOnEnter",
|
||||
"click .uq" : "update",
|
||||
},
|
||||
|
||||
update: function(e) {
|
||||
e.preventDefault();
|
||||
this.item.update(parseInt(this.$('.uqf').val()));
|
||||
},
|
||||
|
||||
updateOnEnter: function(e) {
|
||||
if (e.keyCode == 13) {
|
||||
return this.update(e);
|
||||
}
|
||||
},
|
||||
|
||||
render: function() {
|
||||
this.el.html(_.template(this.template, this.model.toJSON()));
|
||||
return this;
|
||||
}
|
||||
});
|
||||
|
||||
|
||||
var CartWidget = Backbone.View.extend({
|
||||
el: $('.cart-info'),
|
||||
template: $('#store_cart_template').html(),
|
||||
|
||||
initialize: function() {
|
||||
this.collection.bind('change', _.bind(this.render, this));
|
||||
},
|
||||
|
||||
render: function() {
|
||||
this.el.html(
|
||||
_.template(this.template, {
|
||||
'count': this.collection.getTotalCount(),
|
||||
'cost': this.collection.getTotalCost()
|
||||
})).animate({paddingTop: '30px'})
|
||||
.animate({paddingTop: '10px'});
|
||||
}
|
||||
});
|
||||
|
||||
|
||||
var BackboneStore = Backbone.Router.extend({
|
||||
views: {},
|
||||
products: null,
|
||||
cart: null,
|
||||
|
||||
routes: {
|
||||
"": "index",
|
||||
"item/:id": "product",
|
||||
},
|
||||
|
||||
initialize: function(data) {
|
||||
this.cart = new ItemCollection();
|
||||
new CartWidget({collection: this.cart});
|
||||
|
||||
this.products = new ProductCollection([], {
|
||||
url: 'data/items.json'});
|
||||
this.views = {
|
||||
'_index': new ProductListView({
|
||||
collection: this.products
|
||||
})
|
||||
};
|
||||
$.when(this.products.fetch({reset: true}))
|
||||
.then(function() { window.location.hash = ''; });
|
||||
return this;
|
||||
},
|
||||
|
||||
hideAllViews: function () {
|
||||
return _.select(
|
||||
_.map(this.views, function(v) { return v.hide(); }),
|
||||
function (t) { return t != null });
|
||||
},
|
||||
|
||||
index: function() {
|
||||
var view = this.views['_index'];
|
||||
$.when(this.hideAllViews()).then(
|
||||
function() { return view.show(); });
|
||||
},
|
||||
|
||||
product: function(id) {
|
||||
var product, v, view;
|
||||
product = this.products.detect(function(p) { return p.get('id') == (id); })
|
||||
view = ((v = this.views)['item.' + id]) || (v['item.' + id] = (
|
||||
new ProductView({model: product,
|
||||
itemcollection: this.cart}).render()));
|
||||
$.when(this.hideAllViews()).then(
|
||||
function() { view.show(); });
|
||||
}
|
||||
});
|
||||
|
||||
$(document).ready(function() {
|
||||
new BackboneStore();
|
||||
Backbone.history.start();
|
||||
});
|
||||
|
||||
}).call(this);
|
||||
839
underscore.js
839
underscore.js
|
|
@ -1,839 +0,0 @@
|
|||
// Underscore.js 1.1.7
|
||||
// (c) 2011 Jeremy Ashkenas, DocumentCloud Inc.
|
||||
// Underscore is freely distributable under the MIT license.
|
||||
// Portions of Underscore are inspired or borrowed from Prototype,
|
||||
// Oliver Steele's Functional, and John Resig's Micro-Templating.
|
||||
// For all details and documentation:
|
||||
// http://documentcloud.github.com/underscore
|
||||
|
||||
(function() {
|
||||
|
||||
// Baseline setup
|
||||
// --------------
|
||||
|
||||
// Establish the root object, `window` in the browser, or `global` on the server.
|
||||
var root = this;
|
||||
|
||||
// Save the previous value of the `_` variable.
|
||||
var previousUnderscore = root._;
|
||||
|
||||
// Establish the object that gets returned to break out of a loop iteration.
|
||||
var breaker = {};
|
||||
|
||||
// Save bytes in the minified (but not gzipped) version:
|
||||
var ArrayProto = Array.prototype, ObjProto = Object.prototype, FuncProto = Function.prototype;
|
||||
|
||||
// Create quick reference variables for speed access to core prototypes.
|
||||
var slice = ArrayProto.slice,
|
||||
unshift = ArrayProto.unshift,
|
||||
toString = ObjProto.toString,
|
||||
hasOwnProperty = ObjProto.hasOwnProperty;
|
||||
|
||||
// All **ECMAScript 5** native function implementations that we hope to use
|
||||
// are declared here.
|
||||
var
|
||||
nativeForEach = ArrayProto.forEach,
|
||||
nativeMap = ArrayProto.map,
|
||||
nativeReduce = ArrayProto.reduce,
|
||||
nativeReduceRight = ArrayProto.reduceRight,
|
||||
nativeFilter = ArrayProto.filter,
|
||||
nativeEvery = ArrayProto.every,
|
||||
nativeSome = ArrayProto.some,
|
||||
nativeIndexOf = ArrayProto.indexOf,
|
||||
nativeLastIndexOf = ArrayProto.lastIndexOf,
|
||||
nativeIsArray = Array.isArray,
|
||||
nativeKeys = Object.keys,
|
||||
nativeBind = FuncProto.bind;
|
||||
|
||||
// Create a safe reference to the Underscore object for use below.
|
||||
var _ = function(obj) { return new wrapper(obj); };
|
||||
|
||||
// Export the Underscore object for **CommonJS**, with backwards-compatibility
|
||||
// for the old `require()` API. If we're not in CommonJS, add `_` to the
|
||||
// global object.
|
||||
if (typeof module !== 'undefined' && module.exports) {
|
||||
module.exports = _;
|
||||
_._ = _;
|
||||
} else {
|
||||
// Exported as a string, for Closure Compiler "advanced" mode.
|
||||
root['_'] = _;
|
||||
}
|
||||
|
||||
// Current version.
|
||||
_.VERSION = '1.1.7';
|
||||
|
||||
// Collection Functions
|
||||
// --------------------
|
||||
|
||||
// The cornerstone, an `each` implementation, aka `forEach`.
|
||||
// Handles objects with the built-in `forEach`, arrays, and raw objects.
|
||||
// Delegates to **ECMAScript 5**'s native `forEach` if available.
|
||||
var each = _.each = _.forEach = function(obj, iterator, context) {
|
||||
if (obj == null) return;
|
||||
if (nativeForEach && obj.forEach === nativeForEach) {
|
||||
obj.forEach(iterator, context);
|
||||
} else if (obj.length === +obj.length) {
|
||||
for (var i = 0, l = obj.length; i < l; i++) {
|
||||
if (i in obj && iterator.call(context, obj[i], i, obj) === breaker) return;
|
||||
}
|
||||
} else {
|
||||
for (var key in obj) {
|
||||
if (hasOwnProperty.call(obj, key)) {
|
||||
if (iterator.call(context, obj[key], key, obj) === breaker) return;
|
||||
}
|
||||
}
|
||||
}
|
||||
};
|
||||
|
||||
// Return the results of applying the iterator to each element.
|
||||
// Delegates to **ECMAScript 5**'s native `map` if available.
|
||||
_.map = function(obj, iterator, context) {
|
||||
var results = [];
|
||||
if (obj == null) return results;
|
||||
if (nativeMap && obj.map === nativeMap) return obj.map(iterator, context);
|
||||
each(obj, function(value, index, list) {
|
||||
results[results.length] = iterator.call(context, value, index, list);
|
||||
});
|
||||
return results;
|
||||
};
|
||||
|
||||
// **Reduce** builds up a single result from a list of values, aka `inject`,
|
||||
// or `foldl`. Delegates to **ECMAScript 5**'s native `reduce` if available.
|
||||
_.reduce = _.foldl = _.inject = function(obj, iterator, memo, context) {
|
||||
var initial = memo !== void 0;
|
||||
if (obj == null) obj = [];
|
||||
if (nativeReduce && obj.reduce === nativeReduce) {
|
||||
if (context) iterator = _.bind(iterator, context);
|
||||
return initial ? obj.reduce(iterator, memo) : obj.reduce(iterator);
|
||||
}
|
||||
each(obj, function(value, index, list) {
|
||||
if (!initial) {
|
||||
memo = value;
|
||||
initial = true;
|
||||
} else {
|
||||
memo = iterator.call(context, memo, value, index, list);
|
||||
}
|
||||
});
|
||||
if (!initial) throw new TypeError("Reduce of empty array with no initial value");
|
||||
return memo;
|
||||
};
|
||||
|
||||
// The right-associative version of reduce, also known as `foldr`.
|
||||
// Delegates to **ECMAScript 5**'s native `reduceRight` if available.
|
||||
_.reduceRight = _.foldr = function(obj, iterator, memo, context) {
|
||||
if (obj == null) obj = [];
|
||||
if (nativeReduceRight && obj.reduceRight === nativeReduceRight) {
|
||||
if (context) iterator = _.bind(iterator, context);
|
||||
return memo !== void 0 ? obj.reduceRight(iterator, memo) : obj.reduceRight(iterator);
|
||||
}
|
||||
var reversed = (_.isArray(obj) ? obj.slice() : _.toArray(obj)).reverse();
|
||||
return _.reduce(reversed, iterator, memo, context);
|
||||
};
|
||||
|
||||
// Return the first value which passes a truth test. Aliased as `detect`.
|
||||
_.find = _.detect = function(obj, iterator, context) {
|
||||
var result;
|
||||
any(obj, function(value, index, list) {
|
||||
if (iterator.call(context, value, index, list)) {
|
||||
result = value;
|
||||
return true;
|
||||
}
|
||||
});
|
||||
return result;
|
||||
};
|
||||
|
||||
// Return all the elements that pass a truth test.
|
||||
// Delegates to **ECMAScript 5**'s native `filter` if available.
|
||||
// Aliased as `select`.
|
||||
_.filter = _.select = function(obj, iterator, context) {
|
||||
var results = [];
|
||||
if (obj == null) return results;
|
||||
if (nativeFilter && obj.filter === nativeFilter) return obj.filter(iterator, context);
|
||||
each(obj, function(value, index, list) {
|
||||
if (iterator.call(context, value, index, list)) results[results.length] = value;
|
||||
});
|
||||
return results;
|
||||
};
|
||||
|
||||
// Return all the elements for which a truth test fails.
|
||||
_.reject = function(obj, iterator, context) {
|
||||
var results = [];
|
||||
if (obj == null) return results;
|
||||
each(obj, function(value, index, list) {
|
||||
if (!iterator.call(context, value, index, list)) results[results.length] = value;
|
||||
});
|
||||
return results;
|
||||
};
|
||||
|
||||
// Determine whether all of the elements match a truth test.
|
||||
// Delegates to **ECMAScript 5**'s native `every` if available.
|
||||
// Aliased as `all`.
|
||||
_.every = _.all = function(obj, iterator, context) {
|
||||
var result = true;
|
||||
if (obj == null) return result;
|
||||
if (nativeEvery && obj.every === nativeEvery) return obj.every(iterator, context);
|
||||
each(obj, function(value, index, list) {
|
||||
if (!(result = result && iterator.call(context, value, index, list))) return breaker;
|
||||
});
|
||||
return result;
|
||||
};
|
||||
|
||||
// Determine if at least one element in the object matches a truth test.
|
||||
// Delegates to **ECMAScript 5**'s native `some` if available.
|
||||
// Aliased as `any`.
|
||||
var any = _.some = _.any = function(obj, iterator, context) {
|
||||
iterator = iterator || _.identity;
|
||||
var result = false;
|
||||
if (obj == null) return result;
|
||||
if (nativeSome && obj.some === nativeSome) return obj.some(iterator, context);
|
||||
each(obj, function(value, index, list) {
|
||||
if (result |= iterator.call(context, value, index, list)) return breaker;
|
||||
});
|
||||
return !!result;
|
||||
};
|
||||
|
||||
// Determine if a given value is included in the array or object using `===`.
|
||||
// Aliased as `contains`.
|
||||
_.include = _.contains = function(obj, target) {
|
||||
var found = false;
|
||||
if (obj == null) return found;
|
||||
if (nativeIndexOf && obj.indexOf === nativeIndexOf) return obj.indexOf(target) != -1;
|
||||
any(obj, function(value) {
|
||||
if (found = value === target) return true;
|
||||
});
|
||||
return found;
|
||||
};
|
||||
|
||||
// Invoke a method (with arguments) on every item in a collection.
|
||||
_.invoke = function(obj, method) {
|
||||
var args = slice.call(arguments, 2);
|
||||
return _.map(obj, function(value) {
|
||||
return (method.call ? method || value : value[method]).apply(value, args);
|
||||
});
|
||||
};
|
||||
|
||||
// Convenience version of a common use case of `map`: fetching a property.
|
||||
_.pluck = function(obj, key) {
|
||||
return _.map(obj, function(value){ return value[key]; });
|
||||
};
|
||||
|
||||
// Return the maximum element or (element-based computation).
|
||||
_.max = function(obj, iterator, context) {
|
||||
if (!iterator && _.isArray(obj)) return Math.max.apply(Math, obj);
|
||||
var result = {computed : -Infinity};
|
||||
each(obj, function(value, index, list) {
|
||||
var computed = iterator ? iterator.call(context, value, index, list) : value;
|
||||
computed >= result.computed && (result = {value : value, computed : computed});
|
||||
});
|
||||
return result.value;
|
||||
};
|
||||
|
||||
// Return the minimum element (or element-based computation).
|
||||
_.min = function(obj, iterator, context) {
|
||||
if (!iterator && _.isArray(obj)) return Math.min.apply(Math, obj);
|
||||
var result = {computed : Infinity};
|
||||
each(obj, function(value, index, list) {
|
||||
var computed = iterator ? iterator.call(context, value, index, list) : value;
|
||||
computed < result.computed && (result = {value : value, computed : computed});
|
||||
});
|
||||
return result.value;
|
||||
};
|
||||
|
||||
// Sort the object's values by a criterion produced by an iterator.
|
||||
_.sortBy = function(obj, iterator, context) {
|
||||
return _.pluck(_.map(obj, function(value, index, list) {
|
||||
return {
|
||||
value : value,
|
||||
criteria : iterator.call(context, value, index, list)
|
||||
};
|
||||
}).sort(function(left, right) {
|
||||
var a = left.criteria, b = right.criteria;
|
||||
return a < b ? -1 : a > b ? 1 : 0;
|
||||
}), 'value');
|
||||
};
|
||||
|
||||
// Groups the object's values by a criterion produced by an iterator
|
||||
_.groupBy = function(obj, iterator) {
|
||||
var result = {};
|
||||
each(obj, function(value, index) {
|
||||
var key = iterator(value, index);
|
||||
(result[key] || (result[key] = [])).push(value);
|
||||
});
|
||||
return result;
|
||||
};
|
||||
|
||||
// Use a comparator function to figure out at what index an object should
|
||||
// be inserted so as to maintain order. Uses binary search.
|
||||
_.sortedIndex = function(array, obj, iterator) {
|
||||
iterator || (iterator = _.identity);
|
||||
var low = 0, high = array.length;
|
||||
while (low < high) {
|
||||
var mid = (low + high) >> 1;
|
||||
iterator(array[mid]) < iterator(obj) ? low = mid + 1 : high = mid;
|
||||
}
|
||||
return low;
|
||||
};
|
||||
|
||||
// Safely convert anything iterable into a real, live array.
|
||||
_.toArray = function(iterable) {
|
||||
if (!iterable) return [];
|
||||
if (iterable.toArray) return iterable.toArray();
|
||||
if (_.isArray(iterable)) return slice.call(iterable);
|
||||
if (_.isArguments(iterable)) return slice.call(iterable);
|
||||
return _.values(iterable);
|
||||
};
|
||||
|
||||
// Return the number of elements in an object.
|
||||
_.size = function(obj) {
|
||||
return _.toArray(obj).length;
|
||||
};
|
||||
|
||||
// Array Functions
|
||||
// ---------------
|
||||
|
||||
// Get the first element of an array. Passing **n** will return the first N
|
||||
// values in the array. Aliased as `head`. The **guard** check allows it to work
|
||||
// with `_.map`.
|
||||
_.first = _.head = function(array, n, guard) {
|
||||
return (n != null) && !guard ? slice.call(array, 0, n) : array[0];
|
||||
};
|
||||
|
||||
// Returns everything but the first entry of the array. Aliased as `tail`.
|
||||
// Especially useful on the arguments object. Passing an **index** will return
|
||||
// the rest of the values in the array from that index onward. The **guard**
|
||||
// check allows it to work with `_.map`.
|
||||
_.rest = _.tail = function(array, index, guard) {
|
||||
return slice.call(array, (index == null) || guard ? 1 : index);
|
||||
};
|
||||
|
||||
// Get the last element of an array.
|
||||
_.last = function(array) {
|
||||
return array[array.length - 1];
|
||||
};
|
||||
|
||||
// Trim out all falsy values from an array.
|
||||
_.compact = function(array) {
|
||||
return _.filter(array, function(value){ return !!value; });
|
||||
};
|
||||
|
||||
// Return a completely flattened version of an array.
|
||||
_.flatten = function(array) {
|
||||
return _.reduce(array, function(memo, value) {
|
||||
if (_.isArray(value)) return memo.concat(_.flatten(value));
|
||||
memo[memo.length] = value;
|
||||
return memo;
|
||||
}, []);
|
||||
};
|
||||
|
||||
// Return a version of the array that does not contain the specified value(s).
|
||||
_.without = function(array) {
|
||||
return _.difference(array, slice.call(arguments, 1));
|
||||
};
|
||||
|
||||
// Produce a duplicate-free version of the array. If the array has already
|
||||
// been sorted, you have the option of using a faster algorithm.
|
||||
// Aliased as `unique`.
|
||||
_.uniq = _.unique = function(array, isSorted) {
|
||||
return _.reduce(array, function(memo, el, i) {
|
||||
if (0 == i || (isSorted === true ? _.last(memo) != el : !_.include(memo, el))) memo[memo.length] = el;
|
||||
return memo;
|
||||
}, []);
|
||||
};
|
||||
|
||||
// Produce an array that contains the union: each distinct element from all of
|
||||
// the passed-in arrays.
|
||||
_.union = function() {
|
||||
return _.uniq(_.flatten(arguments));
|
||||
};
|
||||
|
||||
// Produce an array that contains every item shared between all the
|
||||
// passed-in arrays. (Aliased as "intersect" for back-compat.)
|
||||
_.intersection = _.intersect = function(array) {
|
||||
var rest = slice.call(arguments, 1);
|
||||
return _.filter(_.uniq(array), function(item) {
|
||||
return _.every(rest, function(other) {
|
||||
return _.indexOf(other, item) >= 0;
|
||||
});
|
||||
});
|
||||
};
|
||||
|
||||
// Take the difference between one array and another.
|
||||
// Only the elements present in just the first array will remain.
|
||||
_.difference = function(array, other) {
|
||||
return _.filter(array, function(value){ return !_.include(other, value); });
|
||||
};
|
||||
|
||||
// Zip together multiple lists into a single array -- elements that share
|
||||
// an index go together.
|
||||
_.zip = function() {
|
||||
var args = slice.call(arguments);
|
||||
var length = _.max(_.pluck(args, 'length'));
|
||||
var results = new Array(length);
|
||||
for (var i = 0; i < length; i++) results[i] = _.pluck(args, "" + i);
|
||||
return results;
|
||||
};
|
||||
|
||||
// If the browser doesn't supply us with indexOf (I'm looking at you, **MSIE**),
|
||||
// we need this function. Return the position of the first occurrence of an
|
||||
// item in an array, or -1 if the item is not included in the array.
|
||||
// Delegates to **ECMAScript 5**'s native `indexOf` if available.
|
||||
// If the array is large and already in sort order, pass `true`
|
||||
// for **isSorted** to use binary search.
|
||||
_.indexOf = function(array, item, isSorted) {
|
||||
if (array == null) return -1;
|
||||
var i, l;
|
||||
if (isSorted) {
|
||||
i = _.sortedIndex(array, item);
|
||||
return array[i] === item ? i : -1;
|
||||
}
|
||||
if (nativeIndexOf && array.indexOf === nativeIndexOf) return array.indexOf(item);
|
||||
for (i = 0, l = array.length; i < l; i++) if (array[i] === item) return i;
|
||||
return -1;
|
||||
};
|
||||
|
||||
|
||||
// Delegates to **ECMAScript 5**'s native `lastIndexOf` if available.
|
||||
_.lastIndexOf = function(array, item) {
|
||||
if (array == null) return -1;
|
||||
if (nativeLastIndexOf && array.lastIndexOf === nativeLastIndexOf) return array.lastIndexOf(item);
|
||||
var i = array.length;
|
||||
while (i--) if (array[i] === item) return i;
|
||||
return -1;
|
||||
};
|
||||
|
||||
// Generate an integer Array containing an arithmetic progression. A port of
|
||||
// the native Python `range()` function. See
|
||||
// [the Python documentation](http://docs.python.org/library/functions.html#range).
|
||||
_.range = function(start, stop, step) {
|
||||
if (arguments.length <= 1) {
|
||||
stop = start || 0;
|
||||
start = 0;
|
||||
}
|
||||
step = arguments[2] || 1;
|
||||
|
||||
var len = Math.max(Math.ceil((stop - start) / step), 0);
|
||||
var idx = 0;
|
||||
var range = new Array(len);
|
||||
|
||||
while(idx < len) {
|
||||
range[idx++] = start;
|
||||
start += step;
|
||||
}
|
||||
|
||||
return range;
|
||||
};
|
||||
|
||||
// Function (ahem) Functions
|
||||
// ------------------
|
||||
|
||||
// Create a function bound to a given object (assigning `this`, and arguments,
|
||||
// optionally). Binding with arguments is also known as `curry`.
|
||||
// Delegates to **ECMAScript 5**'s native `Function.bind` if available.
|
||||
// We check for `func.bind` first, to fail fast when `func` is undefined.
|
||||
_.bind = function(func, obj) {
|
||||
if (func.bind === nativeBind && nativeBind) return nativeBind.apply(func, slice.call(arguments, 1));
|
||||
var args = slice.call(arguments, 2);
|
||||
return function() {
|
||||
return func.apply(obj, args.concat(slice.call(arguments)));
|
||||
};
|
||||
};
|
||||
|
||||
// Bind all of an object's methods to that object. Useful for ensuring that
|
||||
// all callbacks defined on an object belong to it.
|
||||
_.bindAll = function(obj) {
|
||||
var funcs = slice.call(arguments, 1);
|
||||
if (funcs.length == 0) funcs = _.functions(obj);
|
||||
each(funcs, function(f) { obj[f] = _.bind(obj[f], obj); });
|
||||
return obj;
|
||||
};
|
||||
|
||||
// Memoize an expensive function by storing its results.
|
||||
_.memoize = function(func, hasher) {
|
||||
var memo = {};
|
||||
hasher || (hasher = _.identity);
|
||||
return function() {
|
||||
var key = hasher.apply(this, arguments);
|
||||
return hasOwnProperty.call(memo, key) ? memo[key] : (memo[key] = func.apply(this, arguments));
|
||||
};
|
||||
};
|
||||
|
||||
// Delays a function for the given number of milliseconds, and then calls
|
||||
// it with the arguments supplied.
|
||||
_.delay = function(func, wait) {
|
||||
var args = slice.call(arguments, 2);
|
||||
return setTimeout(function(){ return func.apply(func, args); }, wait);
|
||||
};
|
||||
|
||||
// Defers a function, scheduling it to run after the current call stack has
|
||||
// cleared.
|
||||
_.defer = function(func) {
|
||||
return _.delay.apply(_, [func, 1].concat(slice.call(arguments, 1)));
|
||||
};
|
||||
|
||||
// Internal function used to implement `_.throttle` and `_.debounce`.
|
||||
var limit = function(func, wait, debounce) {
|
||||
var timeout;
|
||||
return function() {
|
||||
var context = this, args = arguments;
|
||||
var throttler = function() {
|
||||
timeout = null;
|
||||
func.apply(context, args);
|
||||
};
|
||||
if (debounce) clearTimeout(timeout);
|
||||
if (debounce || !timeout) timeout = setTimeout(throttler, wait);
|
||||
};
|
||||
};
|
||||
|
||||
// Returns a function, that, when invoked, will only be triggered at most once
|
||||
// during a given window of time.
|
||||
_.throttle = function(func, wait) {
|
||||
return limit(func, wait, false);
|
||||
};
|
||||
|
||||
// Returns a function, that, as long as it continues to be invoked, will not
|
||||
// be triggered. The function will be called after it stops being called for
|
||||
// N milliseconds.
|
||||
_.debounce = function(func, wait) {
|
||||
return limit(func, wait, true);
|
||||
};
|
||||
|
||||
// Returns a function that will be executed at most one time, no matter how
|
||||
// often you call it. Useful for lazy initialization.
|
||||
_.once = function(func) {
|
||||
var ran = false, memo;
|
||||
return function() {
|
||||
if (ran) return memo;
|
||||
ran = true;
|
||||
return memo = func.apply(this, arguments);
|
||||
};
|
||||
};
|
||||
|
||||
// Returns the first function passed as an argument to the second,
|
||||
// allowing you to adjust arguments, run code before and after, and
|
||||
// conditionally execute the original function.
|
||||
_.wrap = function(func, wrapper) {
|
||||
return function() {
|
||||
var args = [func].concat(slice.call(arguments));
|
||||
return wrapper.apply(this, args);
|
||||
};
|
||||
};
|
||||
|
||||
// Returns a function that is the composition of a list of functions, each
|
||||
// consuming the return value of the function that follows.
|
||||
_.compose = function() {
|
||||
var funcs = slice.call(arguments);
|
||||
return function() {
|
||||
var args = slice.call(arguments);
|
||||
for (var i = funcs.length - 1; i >= 0; i--) {
|
||||
args = [funcs[i].apply(this, args)];
|
||||
}
|
||||
return args[0];
|
||||
};
|
||||
};
|
||||
|
||||
// Returns a function that will only be executed after being called N times.
|
||||
_.after = function(times, func) {
|
||||
return function() {
|
||||
if (--times < 1) { return func.apply(this, arguments); }
|
||||
};
|
||||
};
|
||||
|
||||
|
||||
// Object Functions
|
||||
// ----------------
|
||||
|
||||
// Retrieve the names of an object's properties.
|
||||
// Delegates to **ECMAScript 5**'s native `Object.keys`
|
||||
_.keys = nativeKeys || function(obj) {
|
||||
if (obj !== Object(obj)) throw new TypeError('Invalid object');
|
||||
var keys = [];
|
||||
for (var key in obj) if (hasOwnProperty.call(obj, key)) keys[keys.length] = key;
|
||||
return keys;
|
||||
};
|
||||
|
||||
// Retrieve the values of an object's properties.
|
||||
_.values = function(obj) {
|
||||
return _.map(obj, _.identity);
|
||||
};
|
||||
|
||||
// Return a sorted list of the function names available on the object.
|
||||
// Aliased as `methods`
|
||||
_.functions = _.methods = function(obj) {
|
||||
var names = [];
|
||||
for (var key in obj) {
|
||||
if (_.isFunction(obj[key])) names.push(key);
|
||||
}
|
||||
return names.sort();
|
||||
};
|
||||
|
||||
// Extend a given object with all the properties in passed-in object(s).
|
||||
_.extend = function(obj) {
|
||||
each(slice.call(arguments, 1), function(source) {
|
||||
for (var prop in source) {
|
||||
if (source[prop] !== void 0) obj[prop] = source[prop];
|
||||
}
|
||||
});
|
||||
return obj;
|
||||
};
|
||||
|
||||
// Fill in a given object with default properties.
|
||||
_.defaults = function(obj) {
|
||||
each(slice.call(arguments, 1), function(source) {
|
||||
for (var prop in source) {
|
||||
if (obj[prop] == null) obj[prop] = source[prop];
|
||||
}
|
||||
});
|
||||
return obj;
|
||||
};
|
||||
|
||||
// Create a (shallow-cloned) duplicate of an object.
|
||||
_.clone = function(obj) {
|
||||
return _.isArray(obj) ? obj.slice() : _.extend({}, obj);
|
||||
};
|
||||
|
||||
// Invokes interceptor with the obj, and then returns obj.
|
||||
// The primary purpose of this method is to "tap into" a method chain, in
|
||||
// order to perform operations on intermediate results within the chain.
|
||||
_.tap = function(obj, interceptor) {
|
||||
interceptor(obj);
|
||||
return obj;
|
||||
};
|
||||
|
||||
// Perform a deep comparison to check if two objects are equal.
|
||||
_.isEqual = function(a, b) {
|
||||
// Check object identity.
|
||||
if (a === b) return true;
|
||||
// Different types?
|
||||
var atype = typeof(a), btype = typeof(b);
|
||||
if (atype != btype) return false;
|
||||
// Basic equality test (watch out for coercions).
|
||||
if (a == b) return true;
|
||||
// One is falsy and the other truthy.
|
||||
if ((!a && b) || (a && !b)) return false;
|
||||
// Unwrap any wrapped objects.
|
||||
if (a._chain) a = a._wrapped;
|
||||
if (b._chain) b = b._wrapped;
|
||||
// One of them implements an isEqual()?
|
||||
if (a.isEqual) return a.isEqual(b);
|
||||
if (b.isEqual) return b.isEqual(a);
|
||||
// Check dates' integer values.
|
||||
if (_.isDate(a) && _.isDate(b)) return a.getTime() === b.getTime();
|
||||
// Both are NaN?
|
||||
if (_.isNaN(a) && _.isNaN(b)) return false;
|
||||
// Compare regular expressions.
|
||||
if (_.isRegExp(a) && _.isRegExp(b))
|
||||
return a.source === b.source &&
|
||||
a.global === b.global &&
|
||||
a.ignoreCase === b.ignoreCase &&
|
||||
a.multiline === b.multiline;
|
||||
// If a is not an object by this point, we can't handle it.
|
||||
if (atype !== 'object') return false;
|
||||
// Check for different array lengths before comparing contents.
|
||||
if (a.length && (a.length !== b.length)) return false;
|
||||
// Nothing else worked, deep compare the contents.
|
||||
var aKeys = _.keys(a), bKeys = _.keys(b);
|
||||
// Different object sizes?
|
||||
if (aKeys.length != bKeys.length) return false;
|
||||
// Recursive comparison of contents.
|
||||
for (var key in a) if (!(key in b) || !_.isEqual(a[key], b[key])) return false;
|
||||
return true;
|
||||
};
|
||||
|
||||
// Is a given array or object empty?
|
||||
_.isEmpty = function(obj) {
|
||||
if (_.isArray(obj) || _.isString(obj)) return obj.length === 0;
|
||||
for (var key in obj) if (hasOwnProperty.call(obj, key)) return false;
|
||||
return true;
|
||||
};
|
||||
|
||||
// Is a given value a DOM element?
|
||||
_.isElement = function(obj) {
|
||||
return !!(obj && obj.nodeType == 1);
|
||||
};
|
||||
|
||||
// Is a given value an array?
|
||||
// Delegates to ECMA5's native Array.isArray
|
||||
_.isArray = nativeIsArray || function(obj) {
|
||||
return toString.call(obj) === '[object Array]';
|
||||
};
|
||||
|
||||
// Is a given variable an object?
|
||||
_.isObject = function(obj) {
|
||||
return obj === Object(obj);
|
||||
};
|
||||
|
||||
// Is a given variable an arguments object?
|
||||
_.isArguments = function(obj) {
|
||||
return !!(obj && hasOwnProperty.call(obj, 'callee'));
|
||||
};
|
||||
|
||||
// Is a given value a function?
|
||||
_.isFunction = function(obj) {
|
||||
return !!(obj && obj.constructor && obj.call && obj.apply);
|
||||
};
|
||||
|
||||
// Is a given value a string?
|
||||
_.isString = function(obj) {
|
||||
return !!(obj === '' || (obj && obj.charCodeAt && obj.substr));
|
||||
};
|
||||
|
||||
// Is a given value a number?
|
||||
_.isNumber = function(obj) {
|
||||
return !!(obj === 0 || (obj && obj.toExponential && obj.toFixed));
|
||||
};
|
||||
|
||||
// Is the given value `NaN`? `NaN` happens to be the only value in JavaScript
|
||||
// that does not equal itself.
|
||||
_.isNaN = function(obj) {
|
||||
return obj !== obj;
|
||||
};
|
||||
|
||||
// Is a given value a boolean?
|
||||
_.isBoolean = function(obj) {
|
||||
return obj === true || obj === false;
|
||||
};
|
||||
|
||||
// Is a given value a date?
|
||||
_.isDate = function(obj) {
|
||||
return !!(obj && obj.getTimezoneOffset && obj.setUTCFullYear);
|
||||
};
|
||||
|
||||
// Is the given value a regular expression?
|
||||
_.isRegExp = function(obj) {
|
||||
return !!(obj && obj.test && obj.exec && (obj.ignoreCase || obj.ignoreCase === false));
|
||||
};
|
||||
|
||||
// Is a given value equal to null?
|
||||
_.isNull = function(obj) {
|
||||
return obj === null;
|
||||
};
|
||||
|
||||
// Is a given variable undefined?
|
||||
_.isUndefined = function(obj) {
|
||||
return obj === void 0;
|
||||
};
|
||||
|
||||
// Utility Functions
|
||||
// -----------------
|
||||
|
||||
// Run Underscore.js in *noConflict* mode, returning the `_` variable to its
|
||||
// previous owner. Returns a reference to the Underscore object.
|
||||
_.noConflict = function() {
|
||||
root._ = previousUnderscore;
|
||||
return this;
|
||||
};
|
||||
|
||||
// Keep the identity function around for default iterators.
|
||||
_.identity = function(value) {
|
||||
return value;
|
||||
};
|
||||
|
||||
// Run a function **n** times.
|
||||
_.times = function (n, iterator, context) {
|
||||
for (var i = 0; i < n; i++) iterator.call(context, i);
|
||||
};
|
||||
|
||||
// Add your own custom functions to the Underscore object, ensuring that
|
||||
// they're correctly added to the OOP wrapper as well.
|
||||
_.mixin = function(obj) {
|
||||
each(_.functions(obj), function(name){
|
||||
addToWrapper(name, _[name] = obj[name]);
|
||||
});
|
||||
};
|
||||
|
||||
// Generate a unique integer id (unique within the entire client session).
|
||||
// Useful for temporary DOM ids.
|
||||
var idCounter = 0;
|
||||
_.uniqueId = function(prefix) {
|
||||
var id = idCounter++;
|
||||
return prefix ? prefix + id : id;
|
||||
};
|
||||
|
||||
// By default, Underscore uses ERB-style template delimiters, change the
|
||||
// following template settings to use alternative delimiters.
|
||||
_.templateSettings = {
|
||||
evaluate : /<%([\s\S]+?)%>/g,
|
||||
interpolate : /<%=([\s\S]+?)%>/g
|
||||
};
|
||||
|
||||
// JavaScript micro-templating, similar to John Resig's implementation.
|
||||
// Underscore templating handles arbitrary delimiters, preserves whitespace,
|
||||
// and correctly escapes quotes within interpolated code.
|
||||
_.template = function(str, data) {
|
||||
var c = _.templateSettings;
|
||||
var tmpl = 'var __p=[],print=function(){__p.push.apply(__p,arguments);};' +
|
||||
'with(obj||{}){__p.push(\'' +
|
||||
str.replace(/\\/g, '\\\\')
|
||||
.replace(/'/g, "\\'")
|
||||
.replace(c.interpolate, function(match, code) {
|
||||
return "'," + code.replace(/\\'/g, "'") + ",'";
|
||||
})
|
||||
.replace(c.evaluate || null, function(match, code) {
|
||||
return "');" + code.replace(/\\'/g, "'")
|
||||
.replace(/[\r\n\t]/g, ' ') + "__p.push('";
|
||||
})
|
||||
.replace(/\r/g, '\\r')
|
||||
.replace(/\n/g, '\\n')
|
||||
.replace(/\t/g, '\\t')
|
||||
+ "');}return __p.join('');";
|
||||
var func = new Function('obj', tmpl);
|
||||
return data ? func(data) : func;
|
||||
};
|
||||
|
||||
// The OOP Wrapper
|
||||
// ---------------
|
||||
|
||||
// If Underscore is called as a function, it returns a wrapped object that
|
||||
// can be used OO-style. This wrapper holds altered versions of all the
|
||||
// underscore functions. Wrapped objects may be chained.
|
||||
var wrapper = function(obj) { this._wrapped = obj; };
|
||||
|
||||
// Expose `wrapper.prototype` as `_.prototype`
|
||||
_.prototype = wrapper.prototype;
|
||||
|
||||
// Helper function to continue chaining intermediate results.
|
||||
var result = function(obj, chain) {
|
||||
return chain ? _(obj).chain() : obj;
|
||||
};
|
||||
|
||||
// A method to easily add functions to the OOP wrapper.
|
||||
var addToWrapper = function(name, func) {
|
||||
wrapper.prototype[name] = function() {
|
||||
var args = slice.call(arguments);
|
||||
unshift.call(args, this._wrapped);
|
||||
return result(func.apply(_, args), this._chain);
|
||||
};
|
||||
};
|
||||
|
||||
// Add all of the Underscore functions to the wrapper object.
|
||||
_.mixin(_);
|
||||
|
||||
// Add all mutator Array functions to the wrapper.
|
||||
each(['pop', 'push', 'reverse', 'shift', 'sort', 'splice', 'unshift'], function(name) {
|
||||
var method = ArrayProto[name];
|
||||
wrapper.prototype[name] = function() {
|
||||
method.apply(this._wrapped, arguments);
|
||||
return result(this._wrapped, this._chain);
|
||||
};
|
||||
});
|
||||
|
||||
// Add all accessor Array functions to the wrapper.
|
||||
each(['concat', 'join', 'slice'], function(name) {
|
||||
var method = ArrayProto[name];
|
||||
wrapper.prototype[name] = function() {
|
||||
return result(method.apply(this._wrapped, arguments), this._chain);
|
||||
};
|
||||
});
|
||||
|
||||
// Start chaining a wrapped Underscore object.
|
||||
wrapper.prototype.chain = function() {
|
||||
this._chain = true;
|
||||
return this;
|
||||
};
|
||||
|
||||
// Extracts the result from a wrapped and chained object.
|
||||
wrapper.prototype.value = function() {
|
||||
return this._wrapped;
|
||||
};
|
||||
|
||||
})();
|
||||
Loading…
Reference in New Issue