backbone.js | |
---|---|
| (function(){ |
Initial Setup | |
The top-level namespace. | var Backbone = {}; |
Keep the version here in sync with | Backbone.VERSION = '0.1.1'; |
Export for both CommonJS and the browser. | (typeof exports !== 'undefined' ? exports : this).Backbone = Backbone; |
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, jQuery owns the | var $ = this.$; |
Helper function to correctly set up the prototype chain, for subclasses.
Similar to | var inherits = function(parent, protoProps, classProps) {
var child = protoProps.hasOwnProperty('constructor') ? protoProps.constructor :
function(){ return parent.apply(this, arguments); };
var ctor = function(){};
ctor.prototype = parent.prototype;
child.prototype = new ctor();
_.extend(child.prototype, protoProps);
if (classProps) _.extend(child, classProps);
child.prototype.constructor = child;
return child;
}; |
Helper function to get a URL from a Model or Collection as a property or as a function. | var getUrl = function(object) {
return _.isFunction(object.url) ? object.url() : object.url;
}; |
Backbone.Events | |
A module that can be mixed in to any object in order to provide it with
custom events. You may | Backbone.Events = { |
Bind an event, specified by a string name, | 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 | 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 : function(ev) {
var list, calls, i, l;
var calls = this._callbacks;
if (!(calls = this._callbacks)) return this;
if (list = calls[ev]) {
for (i = 0, l = list.length; i < l; i++) {
list[i].apply(this, _.rest(arguments));
}
}
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 ( | Backbone.Model = function(attributes) {
this.attributes = {};
this.cid = _.uniqueId('c');
this.set(attributes || {}, {silent : true});
this._previousAttributes = _.clone(this.attributes);
if (this.initialize) this.initialize(attributes);
}; |
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 | _previousAttributes : null, |
Has the item been changed since the last | _changed : false, |
Return a copy of the model's | toJSON : function() {
return _.clone(this.attributes);
}, |
Get the value of an attribute. | get : function(attr) {
return this.attributes[attr];
}, |
Set a hash of model attributes on the object, firing | set : function(attrs, options) { |
Extract attributes and options. | options || (options = {});
if (!attrs) return this;
attrs = attrs.attributes || attrs;
var now = this.attributes; |
Run validation if | if (this.validate) {
var error = this.validate(attrs);
if (error) {
this.trigger('error', this, error);
return false;
}
} |
Check for changes of | if ('id' in attrs) this.id = attrs.id; |
Update attributes. | for (var attr in attrs) {
var val = attrs[attr];
if (val === '') val = null;
if (!_.isEqual(now[attr], val)) {
now[attr] = val;
if (!options.silent) {
this._changed = true;
this.trigger('change:' + attr, this, val);
}
}
} |
Fire the | if (!options.silent && this._changed) this.change();
return this;
}, |
Remove an attribute from the model, firing | unset : function(attr, options) {
options || (options = {});
var value = this.attributes[attr];
delete this.attributes[attr];
if (!options.silent) {
this._changed = true;
this.trigger('change:' + attr, this);
this.change();
}
return value;
}, |
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 | save : function(attrs, options) {
attrs || (attrs = {});
options || (options = {});
if (!this.set(attrs, options)) return false;
var model = this;
var success = function(resp) {
if (!model.set(resp.model)) return false;
if (options.success) options.success(model, resp);
};
var method = this.isNew() ? 'create' : 'update';
Backbone.sync(method, this, success, options.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);
};
Backbone.sync('delete', this, success, options.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 + '/' + this.id;
}, |
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 fire manually fire a | change : function() {
this.trigger('change', this);
this._previousAttributes = _.clone(this.attributes);
this._changed = false;
}, |
Determine if the model has changed since the last | 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) {
var old = this._previousAttributes, now = now || this.attributes, 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
| 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
| previousAttributes : function() {
return _.clone(this._previousAttributes);
}
}); |
Backbone.Collection | |
Provides a standard collection class for our sets of models, ordered
or unordered. If a | 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});
if (this.initialize) this.initialize(models, options);
}; |
Define the Collection's inheritable methods. | _.extend(Backbone.Collection.prototype, Backbone.Events, {
model : Backbone.Model, |
Add a model, or list of models to the set. Pass silent to avoid
firing the | add : function(models, options) {
if (!_.isArray(models)) return this._add(models, options);
for (var i=0; i<models.length; i++) this._add(models[i], options);
return models;
}, |
Remove a model, or a list of models from the set. Pass silent to avoid
firing the | remove : function(models, options) {
if (!_.isArray(models)) return this._remove(models, options);
for (var i=0; i<models.length; i++) this._remove(models[i], options);
return models;
}, |
Get a model from the set by id. | get : function(id) {
return id && 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);
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 | refresh : function(models, options) {
options || (options = {});
models = models || [];
var collection = this;
if (models[0] && !(models[0] instanceof Backbone.Model)) {
models = _.map(models, function(attrs, i) {
return new collection.model(attrs);
});
}
this._reset();
this.add(models, {silent: true});
if (!options.silent) this.trigger('refresh', this);
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(resp.models);
if (options.success) options.success(collection, resp);
};
Backbone.sync('read', this, success, options.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) {
options || (options = {});
if (!(model instanceof Backbone.Model)) model = new this.model(model);
model.collection = this;
var success = function(resp) {
if (!model.set(resp.model)) return false;
model.collection.add(model);
if (options.success) options.success(model, resp);
};
return model.save(null, {success : success, error : options.error});
}, |
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 | _add : function(model, options) {
options || (options = {});
var already = this.get(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) this.trigger('add', model);
return model;
}, |
Internal implementation of removing a single model from the set, updating
hash indexes for | _remove : function(model, options) {
options || (options = {});
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);
model.unbind('all', this._boundOnModelEvent);
this.length--;
if (!options.silent) this.trigger('remove', model);
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. | _onModelEvent : function(ev, model, error) {
switch (ev) {
case 'change':
if (model.hasChanged('id')) {
delete this._byId[model.previous('id')];
this._byId[model.id] = model;
}
this.trigger('change', model);
break;
case 'error':
this.trigger('error', model, error);
}
}
}); |
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 | _.each(methods, function(method) {
Backbone.Collection.prototype[method] = function() {
return _[method].apply(_, [this.models].concat(_.toArray(arguments)));
};
}); |
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 || {});
if (this.options.el) {
this.el = this.options.el;
} else {
var attrs = {};
if (this.id) attrs.id = this.id;
if (this.className) attrs.className = this.className;
this.el = this.make(this.tagName, attrs);
}
if (this.initialize) this.initialize(options);
}; |
jQuery lookup, scoped to DOM elements within the current view. This should be prefered to global jQuery lookups, if you're dealing with a specific view. | var jQueryDelegate = function(selector) {
return $(selector, this.el);
}; |
Cached regex to split keys for | var eventSplitter = /^(\w+)\s*(.*)$/; |
Set up all inheritable Backbone.View properties and methods. | _.extend(Backbone.View.prototype, { |
The default | tagName : 'div', |
Attach the jQuery function as the | $ : jQueryDelegate,
jQuery : jQueryDelegate, |
render is the core function that your view should override, in order
to populate its element ( | render : function() {
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. | 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 {"event selector": "callback"}
pairs. Callbacks will be bound to the view, with | handleEvents : function(events) {
$(this.el).unbind();
if (!(events || (events = this.events))) return this;
for (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 === '' || eventName == 'change') {
$(this.el).bind(eventName, method);
} else {
$(this.el).delegate(selector, eventName, method);
}
}
return this;
}, |
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.id) this.id = options.id;
if (options.className) this.className = options.className;
if (options.tagName) this.tagName = options.tagName;
this.options = options;
}
}); |
Set up inheritance for the model, collection, and view. | var extend = Backbone.Model.extend = Backbone.Collection.extend = Backbone.View.extend = function (protoProps, classProps) {
var child = inherits(this, protoProps, classProps);
child.extend = extend;
return child;
}; |
Map from CRUD to HTTP for our default | var methodMap = {
'create': 'POST',
'update': 'PUT',
'delete': 'DELETE',
'read' : 'GET'
}; |
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 jQuery to make a RESTful Ajax request
to the model's
| Backbone.sync = function(method, model, success, error) {
$.ajax({
url : getUrl(model),
type : methodMap[method],
data : {model : JSON.stringify(model)},
dataType : 'json',
success : success,
error : error
});
};
})();
|