The-Backbone-Store/backbone.js

1012 lines
35 KiB
JavaScript

// Backbone.js 0.3.3
// (c) 2010 Jeremy Ashkenas, DocumentCloud Inc.
// Backbone may be freely distributed under the MIT license.
// For all details and documentation:
// http://documentcloud.github.com/backbone
(function(){
// Initial Setup
// -------------
// The top-level namespace. All public Backbone classes and modules will
// be attached to this. Exported for both CommonJS and the browser.
var Backbone;
if (typeof exports !== 'undefined') {
Backbone = exports;
} else {
Backbone = this.Backbone = {};
}
// Current version of the library. Keep in sync with `package.json`.
Backbone.VERSION = '0.3.3';
// Require Underscore, if we're on the server, and it's not already present.
var _ = this._;
if (!_ && (typeof require !== 'undefined')) _ = require("underscore")._;
// For Backbone's purposes, either jQuery or Zepto owns the `$` variable.
var $ = this.jQuery || this.Zepto;
// Turn on `emulateHTTP` to use support legacy HTTP servers. Setting this option will
// fake `"PUT"` and `"DELETE"` requests via the `_method` parameter and set a
// `X-Http-Method-Override` header.
Backbone.emulateHTTP = false;
// Turn on `emulateJSON` to support legacy servers that can't deal with direct
// `application/json` requests ... will encode the body as
// `application/x-www-form-urlencoded` instead and will send the model in a
// form param named `model`.
Backbone.emulateJSON = false;
// Backbone.Events
// -----------------
// A module that can be mixed in to *any object* in order to provide it with
// custom events. You may `bind` or `unbind` a callback function to an event;
// `trigger`-ing an event fires all callbacks in succession.
//
// var object = {};
// _.extend(object, Backbone.Events);
// object.bind('expand', function(){ alert('expanded'); });
// object.trigger('expand');
//
Backbone.Events = {
// Bind an event, specified by a string name, `ev`, to a `callback` function.
// Passing `"all"` will bind the callback to all events fired.
bind : function(ev, callback) {
var calls = this._callbacks || (this._callbacks = {});
var list = this._callbacks[ev] || (this._callbacks[ev] = []);
list.push(callback);
return this;
},
// Remove one or many callbacks. If `callback` is null, removes all
// callbacks for the event. If `ev` is null, removes all bound callbacks
// for all events.
unbind : function(ev, callback) {
var calls;
if (!ev) {
this._callbacks = {};
} else if (calls = this._callbacks) {
if (!callback) {
calls[ev] = [];
} else {
var list = calls[ev];
if (!list) return this;
for (var i = 0, l = list.length; i < l; i++) {
if (callback === list[i]) {
list.splice(i, 1);
break;
}
}
}
}
return this;
},
// Trigger an event, firing all bound callbacks. Callbacks are passed the
// same arguments as `trigger` is, apart from the event name.
// Listening for `"all"` passes the true event name as the first argument.
trigger : function(ev) {
var list, calls, i, l;
if (!(calls = this._callbacks)) return this;
if (list = calls[ev]) {
for (i = 0, l = list.length; i < l; i++) {
list[i].apply(this, Array.prototype.slice.call(arguments, 1));
}
}
if (list = calls['all']) {
for (i = 0, l = list.length; i < l; i++) {
list[i].apply(this, arguments);
}
}
return this;
}
};
// Backbone.Model
// --------------
// Create a new model, with defined attributes. A client id (`cid`)
// is automatically generated and assigned for you.
Backbone.Model = function(attributes, options) {
attributes || (attributes = {});
if (this.defaults) attributes = _.extend({}, this.defaults, attributes);
this.attributes = {};
this._escapedAttributes = {};
this.cid = _.uniqueId('c');
this.set(attributes, {silent : true});
this._previousAttributes = _.clone(this.attributes);
if (options && options.collection) this.collection = options.collection;
this.initialize(attributes, options);
};
// Attach all inheritable methods to the Model prototype.
_.extend(Backbone.Model.prototype, Backbone.Events, {
// A snapshot of the model's previous attributes, taken immediately
// after the last `"change"` event was fired.
_previousAttributes : null,
// Has the item been changed since the last `"change"` event?
_changed : false,
// Initialize is an empty function by default. Override it with your own
// initialization logic.
initialize : function(){},
// Return a copy of the model's `attributes` object.
toJSON : function() {
return _.clone(this.attributes);
},
// Get the value of an attribute.
get : function(attr) {
return this.attributes[attr];
},
// Get the HTML-escaped value of an attribute.
escape : function(attr) {
var html;
if (html = this._escapedAttributes[attr]) return html;
var val = this.attributes[attr];
return this._escapedAttributes[attr] = escapeHTML(val == null ? '' : val);
},
// Set a hash of model attributes on the object, firing `"change"` unless you
// choose to silence it.
set : function(attrs, options) {
// Extract attributes and options.
options || (options = {});
if (!attrs) return this;
if (attrs.attributes) attrs = attrs.attributes;
var now = this.attributes, escaped = this._escapedAttributes;
// Run validation.
if (!options.silent && this.validate && !this._performValidation(attrs, options)) return false;
// Check for changes of `id`.
if ('id' in attrs) this.id = attrs.id;
// Update attributes.
for (var attr in attrs) {
var val = attrs[attr];
if (!_.isEqual(now[attr], val)) {
now[attr] = val;
delete escaped[attr];
if (!options.silent) {
this._changed = true;
this.trigger('change:' + attr, this, val, options);
}
}
}
// Fire the `"change"` event, if the model has been changed.
if (!options.silent && this._changed) this.change(options);
return this;
},
// Remove an attribute from the model, firing `"change"` unless you choose
// to silence it.
unset : function(attr, options) {
options || (options = {});
var value = this.attributes[attr];
// Run validation.
var validObj = {};
validObj[attr] = void 0;
if (!options.silent && this.validate && !this._performValidation(validObj, options)) return false;
// Remove the attribute.
delete this.attributes[attr];
delete this._escapedAttributes[attr];
if (!options.silent) {
this._changed = true;
this.trigger('change:' + attr, this, void 0, options);
this.change(options);
}
return this;
},
// Clear all attributes on the model, firing `"change"` unless you choose
// to silence it.
clear : function(options) {
options || (options = {});
var old = this.attributes;
// Run validation.
var validObj = {};
for (attr in old) validObj[attr] = void 0;
if (!options.silent && this.validate && !this._performValidation(validObj, options)) return false;
this.attributes = {};
this._escapedAttributes = {};
if (!options.silent) {
this._changed = true;
for (attr in old) {
this.trigger('change:' + attr, this, void 0, options);
}
this.change(options);
}
return this;
},
// Fetch the model from the server. If the server's representation of the
// model differs from its current attributes, they will be overriden,
// triggering a `"change"` event.
fetch : function(options) {
options || (options = {});
var model = this;
var success = function(resp) {
if (!model.set(model.parse(resp), options)) return false;
if (options.success) options.success(model, resp);
};
var error = wrapError(options.error, model, options);
(this.sync || Backbone.sync)('read', this, success, error);
return this;
},
// Set a hash of model attributes, and sync the model to the server.
// If the server returns an attributes hash that differs, the model's
// state will be `set` again.
save : function(attrs, options) {
options || (options = {});
if (attrs && !this.set(attrs, options)) return false;
var model = this;
var success = function(resp) {
if (!model.set(model.parse(resp), options)) return false;
if (options.success) options.success(model, resp);
};
var error = wrapError(options.error, model, options);
var method = this.isNew() ? 'create' : 'update';
(this.sync || Backbone.sync)(method, this, success, error);
return this;
},
// Destroy this model on the server. Upon success, the model is removed
// from its collection, if it has one.
destroy : function(options) {
options || (options = {});
var model = this;
var success = function(resp) {
if (model.collection) model.collection.remove(model);
if (options.success) options.success(model, resp);
};
var error = wrapError(options.error, model, options);
(this.sync || Backbone.sync)('delete', this, success, error);
return this;
},
// Default URL for the model's representation on the server -- if you're
// using Backbone's restful methods, override this to change the endpoint
// that will be called.
url : function() {
var base = getUrl(this.collection);
if (this.isNew()) return base;
return base + (base.charAt(base.length - 1) == '/' ? '' : '/') + this.id;
},
// **parse** converts a response into the hash of attributes to be `set` on
// the model. The default implementation is just to pass the response along.
parse : function(resp) {
return resp;
},
// Create a new model with identical attributes to this one.
clone : function() {
return new this.constructor(this);
},
// A model is new if it has never been saved to the server, and has a negative
// ID.
isNew : function() {
return !this.id;
},
// Call this method to manually fire a `change` event for this model.
// Calling this will cause all objects observing the model to update.
change : function(options) {
this.trigger('change', this, options);
this._previousAttributes = _.clone(this.attributes);
this._changed = false;
},
// Determine if the model has changed since the last `"change"` event.
// If you specify an attribute name, determine if that attribute has changed.
hasChanged : function(attr) {
if (attr) return this._previousAttributes[attr] != this.attributes[attr];
return this._changed;
},
// Return an object containing all the attributes that have changed, or false
// if there are no changed attributes. Useful for determining what parts of a
// view need to be updated and/or what attributes need to be persisted to
// the server.
changedAttributes : function(now) {
now || (now = this.attributes);
var old = this._previousAttributes;
var changed = false;
for (var attr in now) {
if (!_.isEqual(old[attr], now[attr])) {
changed = changed || {};
changed[attr] = now[attr];
}
}
return changed;
},
// Get the previous value of an attribute, recorded at the time the last
// `"change"` event was fired.
previous : function(attr) {
if (!attr || !this._previousAttributes) return null;
return this._previousAttributes[attr];
},
// Get all of the attributes of the model at the time of the previous
// `"change"` event.
previousAttributes : function() {
return _.clone(this._previousAttributes);
},
// Run validation against a set of incoming attributes, returning `true`
// if all is well. If a specific `error` callback has been passed,
// call that instead of firing the general `"error"` event.
_performValidation : function(attrs, options) {
var error = this.validate(attrs);
if (error) {
if (options.error) {
options.error(this, error);
} else {
this.trigger('error', this, error, options);
}
return false;
}
return true;
}
});
// Backbone.Collection
// -------------------
// Provides a standard collection class for our sets of models, ordered
// or unordered. If a `comparator` is specified, the Collection will maintain
// its models in sort order, as they're added and removed.
Backbone.Collection = function(models, options) {
options || (options = {});
if (options.comparator) {
this.comparator = options.comparator;
delete options.comparator;
}
this._boundOnModelEvent = _.bind(this._onModelEvent, this);
this._reset();
if (models) this.refresh(models, {silent: true});
this.initialize(models, options);
};
// Define the Collection's inheritable methods.
_.extend(Backbone.Collection.prototype, Backbone.Events, {
// The default model for a collection is just a **Backbone.Model**.
// This should be overridden in most cases.
model : Backbone.Model,
// Initialize is an empty function by default. Override it with your own
// initialization logic.
initialize : function(){},
// The JSON representation of a Collection is an array of the
// models' attributes.
toJSON : function() {
return this.map(function(model){ return model.toJSON(); });
},
// Add a model, or list of models to the set. Pass **silent** to avoid
// firing the `added` event for every new model.
add : function(models, options) {
if (_.isArray(models)) {
for (var i = 0, l = models.length; i < l; i++) {
this._add(models[i], options);
}
} else {
this._add(models, options);
}
return this;
},
// Remove a model, or a list of models from the set. Pass silent to avoid
// firing the `removed` event for every model removed.
remove : function(models, options) {
if (_.isArray(models)) {
for (var i = 0, l = models.length; i < l; i++) {
this._remove(models[i], options);
}
} else {
this._remove(models, options);
}
return this;
},
// Get a model from the set by id.
get : function(id) {
if (id == null) return null;
return this._byId[id.id != null ? id.id : id];
},
// Get a model from the set by client id.
getByCid : function(cid) {
return cid && this._byCid[cid.cid || cid];
},
// Get the model at the given index.
at: function(index) {
return this.models[index];
},
// Force the collection to re-sort itself. You don't need to call this under normal
// circumstances, as the set will maintain sort order as each item is added.
sort : function(options) {
options || (options = {});
if (!this.comparator) throw new Error('Cannot sort a set without a comparator');
this.models = this.sortBy(this.comparator);
if (!options.silent) this.trigger('refresh', this, options);
return this;
},
// Pluck an attribute from each model in the collection.
pluck : function(attr) {
return _.map(this.models, function(model){ return model.get(attr); });
},
// When you have more items than you want to add or remove individually,
// you can refresh the entire set with a new list of models, without firing
// any `added` or `removed` events. Fires `refresh` when finished.
refresh : function(models, options) {
models || (models = []);
options || (options = {});
this._reset();
this.add(models, {silent: true});
if (!options.silent) this.trigger('refresh', this, options);
return this;
},
// Fetch the default set of models for this collection, refreshing the
// collection when they arrive.
fetch : function(options) {
options || (options = {});
var collection = this;
var success = function(resp) {
collection.refresh(collection.parse(resp));
if (options.success) options.success(collection, resp);
};
var error = wrapError(options.error, collection, options);
(this.sync || Backbone.sync)('read', this, success, error);
return this;
},
// Create a new instance of a model in this collection. After the model
// has been created on the server, it will be added to the collection.
create : function(model, options) {
var coll = this;
options || (options = {});
if (!(model instanceof Backbone.Model)) {
model = new this.model(model, {collection: coll});
} else {
model.collection = coll;
}
var success = function(nextModel, resp) {
coll.add(nextModel);
if (options.success) options.success(nextModel, resp);
};
return model.save(null, {success : success, error : options.error});
},
// **parse** converts a response into a list of models to be added to the
// collection. The default implementation is just to pass it through.
parse : function(resp) {
return resp;
},
// Proxy to _'s chain. Can't be proxied the same way the rest of the
// underscore methods are proxied because it relies on the underscore
// constructor.
chain: function () {
return _(this.models).chain();
},
// Reset all internal state. Called when the collection is refreshed.
_reset : function(options) {
this.length = 0;
this.models = [];
this._byId = {};
this._byCid = {};
},
// Internal implementation of adding a single model to the set, updating
// hash indexes for `id` and `cid` lookups.
_add : function(model, options) {
options || (options = {});
if (!(model instanceof Backbone.Model)) {
model = new this.model(model, {collection: this});
}
var already = this.getByCid(model);
if (already) throw new Error(["Can't add the same model to a set twice", already.id]);
this._byId[model.id] = model;
this._byCid[model.cid] = model;
model.collection = this;
var index = this.comparator ? this.sortedIndex(model, this.comparator) : this.length;
this.models.splice(index, 0, model);
model.bind('all', this._boundOnModelEvent);
this.length++;
if (!options.silent) model.trigger('add', model, this, options);
return model;
},
// Internal implementation of removing a single model from the set, updating
// hash indexes for `id` and `cid` lookups.
_remove : function(model, options) {
options || (options = {});
model = this.getByCid(model) || this.get(model);
if (!model) return null;
delete this._byId[model.id];
delete this._byCid[model.cid];
delete model.collection;
this.models.splice(this.indexOf(model), 1);
this.length--;
if (!options.silent) model.trigger('remove', model, this, options);
model.unbind('all', this._boundOnModelEvent);
return model;
},
// Internal method called every time a model in the set fires an event.
// Sets need to update their indexes when models change ids. All other
// events simply proxy through.
_onModelEvent : function(ev, model) {
if (ev === 'change:id') {
delete this._byId[model.previous('id')];
this._byId[model.id] = model;
}
this.trigger.apply(this, arguments);
}
});
// Underscore methods that we want to implement on the Collection.
var methods = ['forEach', 'each', 'map', 'reduce', 'reduceRight', 'find', 'detect',
'filter', 'select', 'reject', 'every', 'all', 'some', 'any', 'include',
'invoke', 'max', 'min', 'sortBy', 'sortedIndex', 'toArray', 'size',
'first', 'rest', 'last', 'without', 'indexOf', 'lastIndexOf', 'isEmpty'];
// Mix in each Underscore method as a proxy to `Collection#models`.
_.each(methods, function(method) {
Backbone.Collection.prototype[method] = function() {
return _[method].apply(_, [this.models].concat(_.toArray(arguments)));
};
});
// Backbone.Controller
// -------------------
// Controllers map faux-URLs to actions, and fire events when routes are
// matched. Creating a new one sets its `routes` hash, if not set statically.
Backbone.Controller = function(options) {
options || (options = {});
if (options.routes) this.routes = options.routes;
this._bindRoutes();
this.initialize(options);
};
// Cached regular expressions for matching named param parts and splatted
// parts of route strings.
var namedParam = /:([\w\d]+)/g;
var splatParam = /\*([\w\d]+)/g;
// Set up all inheritable **Backbone.Controller** properties and methods.
_.extend(Backbone.Controller.prototype, Backbone.Events, {
// Initialize is an empty function by default. Override it with your own
// initialization logic.
initialize : function(){},
// Manually bind a single named route to a callback. For example:
//
// this.route('search/:query/p:num', 'search', function(query, num) {
// ...
// });
//
route : function(route, name, callback) {
Backbone.history || (Backbone.history = new Backbone.History);
if (!_.isRegExp(route)) route = this._routeToRegExp(route);
Backbone.history.route(route, _.bind(function(fragment) {
var args = this._extractParameters(route, fragment);
callback.apply(this, args);
this.trigger.apply(this, ['route:' + name].concat(args));
}, this));
},
// Simple proxy to `Backbone.history` to save a fragment into the history,
// without triggering routes.
saveLocation : function(fragment) {
Backbone.history.saveLocation(fragment);
},
// Bind all defined routes to `Backbone.history`.
_bindRoutes : function() {
if (!this.routes) return;
for (var route in this.routes) {
var name = this.routes[route];
this.route(route, name, this[name]);
}
},
// Convert a route string into a regular expression, suitable for matching
// against the current location fragment.
_routeToRegExp : function(route) {
route = route.replace(namedParam, "([^\/]*)").replace(splatParam, "(.*?)");
return new RegExp('^' + route + '$');
},
// Given a route, and a URL fragment that it matches, return the array of
// extracted parameters.
_extractParameters : function(route, fragment) {
return route.exec(fragment).slice(1);
}
});
// Backbone.History
// ----------------
// Handles cross-browser history management, based on URL hashes. If the
// browser does not support `onhashchange`, falls back to polling.
Backbone.History = function() {
this.handlers = [];
this.fragment = this.getFragment();
_.bindAll(this, 'checkUrl');
};
// Cached regex for cleaning hashes.
var hashStrip = /^#*/;
// Set up all inheritable **Backbone.History** properties and methods.
_.extend(Backbone.History.prototype, {
// The default interval to poll for hash changes, if necessary, is
// twenty times a second.
interval: 50,
// Get the cross-browser normalized URL fragment.
getFragment : function(loc) {
return (loc || window.location).hash.replace(hashStrip, '');
},
// Start the hash change handling, returning `true` if the current URL matches
// an existing route, and `false` otherwise.
start : function() {
var docMode = document.documentMode;
var oldIE = ($.browser.msie && (!docMode || docMode <= 7));
if (oldIE) {
this.iframe = $('<iframe src="javascript:0" tabindex="-1" />').hide().appendTo('body')[0].contentWindow;
}
if ('onhashchange' in window && !oldIE) {
$(window).bind('hashchange', this.checkUrl);
} else {
setInterval(this.checkUrl, this.interval);
}
return this.loadUrl();
},
// Add a route to be tested when the hash changes. Routes are matched in the
// order they are added.
route : function(route, callback) {
this.handlers.push({route : route, callback : callback});
},
// Checks the current URL to see if it has changed, and if it has,
// calls `loadUrl`, normalizing across the hidden iframe.
checkUrl : function() {
var current = this.getFragment();
if (current == this.fragment && this.iframe) {
current = this.getFragment(this.iframe.location);
}
if (current == this.fragment ||
current == decodeURIComponent(this.fragment)) return false;
if (this.iframe) {
window.location.hash = this.iframe.location.hash = current;
}
this.loadUrl();
},
// Attempt to load the current URL fragment. If a route succeeds with a
// match, returns `true`. If no defined routes matches the fragment,
// returns `false`.
loadUrl : function() {
var fragment = this.fragment = this.getFragment();
var matched = _.any(this.handlers, function(handler) {
if (handler.route.test(fragment)) {
handler.callback(fragment);
return true;
}
});
return matched;
},
// Save a fragment into the hash history. You are responsible for properly
// URL-encoding the fragment in advance. This does not trigger
// a `hashchange` event.
saveLocation : function(fragment) {
fragment = (fragment || '').replace(hashStrip, '');
if (this.fragment == fragment) return;
window.location.hash = this.fragment = fragment;
if (this.iframe && (fragment != this.getFragment(this.iframe.location))) {
this.iframe.document.open().close();
this.iframe.location.hash = fragment;
}
}
});
// Backbone.View
// -------------
// Creating a Backbone.View creates its initial element outside of the DOM,
// if an existing element is not provided...
Backbone.View = function(options) {
this._configure(options || {});
this._ensureElement();
this.delegateEvents();
this.initialize(options);
};
// Element lookup, scoped to DOM elements within the current view.
// This should be prefered to global lookups, if you're dealing with
// a specific view.
var selectorDelegate = function(selector) {
return $(selector, this.el);
};
// Cached regex to split keys for `delegate`.
var eventSplitter = /^(\w+)\s*(.*)$/;
// Set up all inheritable **Backbone.View** properties and methods.
_.extend(Backbone.View.prototype, Backbone.Events, {
// The default `tagName` of a View's element is `"div"`.
tagName : 'div',
// Attach the `selectorDelegate` function as the `$` property.
$ : selectorDelegate,
// Initialize is an empty function by default. Override it with your own
// initialization logic.
initialize : function(){},
// **render** is the core function that your view should override, in order
// to populate its element (`this.el`), with the appropriate HTML. The
// convention is for **render** to always return `this`.
render : function() {
return this;
},
// Remove this view from the DOM. Note that the view isn't present in the
// DOM by default, so calling this method may be a no-op.
remove : function() {
$(this.el).remove();
return this;
},
// For small amounts of DOM Elements, where a full-blown template isn't
// needed, use **make** to manufacture elements, one at a time.
//
// var el = this.make('li', {'class': 'row'}, this.model.get('title'));
//
make : function(tagName, attributes, content) {
var el = document.createElement(tagName);
if (attributes) $(el).attr(attributes);
if (content) $(el).html(content);
return el;
},
// Set callbacks, where `this.callbacks` is a hash of
//
// *{"event selector": "callback"}*
//
// {
// 'mousedown .title': 'edit',
// 'click .button': 'save'
// }
//
// pairs. Callbacks will be bound to the view, with `this` set properly.
// Uses event delegation for efficiency.
// Omitting the selector binds the event to `this.el`.
// This only works for delegate-able events: not `focus`, `blur`, and
// not `change`, `submit`, and `reset` in Internet Explorer.
delegateEvents : function(events) {
if (!(events || (events = this.events))) return;
$(this.el).unbind();
for (var key in events) {
var methodName = events[key];
var match = key.match(eventSplitter);
var eventName = match[1], selector = match[2];
var method = _.bind(this[methodName], this);
if (selector === '') {
$(this.el).bind(eventName, method);
} else {
$(this.el).delegate(selector, eventName, method);
}
}
},
// Performs the initial configuration of a View with a set of options.
// Keys with special meaning *(model, collection, id, className)*, are
// attached directly to the view.
_configure : function(options) {
if (this.options) options = _.extend({}, this.options, options);
if (options.model) this.model = options.model;
if (options.collection) this.collection = options.collection;
if (options.el) this.el = options.el;
if (options.id) this.id = options.id;
if (options.className) this.className = options.className;
if (options.tagName) this.tagName = options.tagName;
this.options = options;
},
// Ensure that the View has a DOM element to render into.
_ensureElement : function() {
if (this.el) return;
var attrs = {};
if (this.id) attrs.id = this.id;
if (this.className) attrs["class"] = this.className;
this.el = this.make(this.tagName, attrs);
}
});
// The self-propagating extend function that Backbone classes use.
var extend = function (protoProps, classProps) {
var child = inherits(this, protoProps, classProps);
child.extend = extend;
return child;
};
// Set up inheritance for the model, collection, and view.
Backbone.Model.extend = Backbone.Collection.extend =
Backbone.Controller.extend = Backbone.View.extend = extend;
// Map from CRUD to HTTP for our default `Backbone.sync` implementation.
var methodMap = {
'create': 'POST',
'update': 'PUT',
'delete': 'DELETE',
'read' : 'GET'
};
// Backbone.sync
// -------------
// Override this function to change the manner in which Backbone persists
// models to the server. You will be passed the type of request, and the
// model in question. By default, uses makes a RESTful Ajax request
// to the model's `url()`. Some possible customizations could be:
//
// * Use `setTimeout` to batch rapid-fire updates into a single request.
// * Send up the models as XML instead of JSON.
// * Persist models via WebSockets instead of Ajax.
//
// Turn on `Backbone.emulateHTTP` in order to send `PUT` and `DELETE` requests
// as `POST`, with a `_method` parameter containing the true HTTP method,
// as well as all requests with the body as `application/x-www-form-urlencoded` instead of
// `application/json` with the model in a param named `model`.
// Useful when interfacing with server-side languages like **PHP** that make
// it difficult to read the body of `PUT` requests.
Backbone.sync = function(method, model, success, error) {
var type = methodMap[method];
var modelJSON = (method === 'create' || method === 'update') ?
JSON.stringify(model.toJSON()) : null;
// Default JSON-request options.
var params = {
url: getUrl(model),
type: type,
contentType: 'application/json',
data: modelJSON,
dataType: 'json',
processData: false,
success: success,
error: error
};
// For older servers, emulate JSON by encoding the request into an HTML-form.
if (Backbone.emulateJSON) {
params.contentType = 'application/x-www-form-urlencoded';
params.processData = true;
params.data = modelJSON ? {model : modelJSON} : {};
}
// For older servers, emulate HTTP by mimicking the HTTP method with `_method`
// And an `X-HTTP-Method-Override` header.
if (Backbone.emulateHTTP) {
if (type === 'PUT' || type === 'DELETE') {
if (Backbone.emulateJSON) params.data._method = type;
params.type = 'POST';
params.beforeSend = function(xhr) {
xhr.setRequestHeader("X-HTTP-Method-Override", type);
};
}
}
// Make the request.
$.ajax(params);
};
// Helpers
// -------
// Shared empty constructor function to aid in prototype-chain creation.
var ctor = function(){};
// Helper function to correctly set up the prototype chain, for subclasses.
// Similar to `goog.inherits`, but uses a hash of prototype properties and
// class properties to be extended.
var inherits = function(parent, protoProps, staticProps) {
var child;
// The constructor function for the new subclass is either defined by you
// (the "constructor" property in your `extend` definition), or defaulted
// by us to simply call `super()`.
if (protoProps && protoProps.hasOwnProperty('constructor')) {
child = protoProps.constructor;
} else {
child = function(){ return parent.apply(this, arguments); };
}
// Set the prototype chain to inherit from `parent`, without calling
// `parent`'s constructor function.
ctor.prototype = parent.prototype;
child.prototype = new ctor();
// Add prototype properties (instance properties) to the subclass,
// if supplied.
if (protoProps) _.extend(child.prototype, protoProps);
// Add static properties to the constructor function, if supplied.
if (staticProps) _.extend(child, staticProps);
// Correctly set child's `prototype.constructor`, for `instanceof`.
child.prototype.constructor = child;
// Set a convenience property in case the parent's prototype is needed later.
child.__super__ = parent.prototype;
return child;
};
// Helper function to get a URL from a Model or Collection as a property
// or as a function.
var getUrl = function(object) {
if (!(object && object.url)) throw new Error("A 'url' property or function must be specified");
return _.isFunction(object.url) ? object.url() : object.url;
};
// Wrap an optional error callback with a fallback error event.
var wrapError = function(onError, model, options) {
return function(resp) {
if (onError) {
onError(model, resp);
} else {
model.trigger('error', model, resp, options);
}
};
};
// Helper function to escape a string for HTML rendering.
var escapeHTML = function(string) {
return string.replace(/&(?!\w+;)/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;');
};
})();