Files
dss/static/js/lib/backbone.associations.js
2013-12-16 22:31:35 +00:00

574 lines
25 KiB
JavaScript

//
// Backbone-associations.js 0.5.4
//
// (c) 2013 Dhruva Ray, Jaynti Kanani, Persistent Systems Ltd.
// Backbone-associations may be freely distributed under the MIT license.
// For all details and documentation:
// https://github.com/dhruvaray/backbone-associations/
//
// Initial Setup
// --------------
(function () {
"use strict";
// Save a reference to the global object (`window` in the browser, `exports`
// on the server).
var root = this;
// The top-level namespace. All public Backbone classes and modules will be attached to this.
// Exported for the browser and CommonJS.
var _, Backbone, BackboneModel, BackboneCollection, ModelProto,
CollectionProto, defaultEvents, AssociatedModel, pathChecker,
collectionEvents, delimiters, pathSeparator;
if (typeof exports !== 'undefined') {
_ = require('underscore');
Backbone = require('backbone');
if (typeof module !== 'undefined' && module.exports) {
module.exports = Backbone;
}
exports = Backbone;
} else {
_ = root._;
Backbone = root.Backbone;
}
// Create local reference `Model` prototype.
BackboneModel = Backbone.Model;
BackboneCollection = Backbone.Collection;
ModelProto = BackboneModel.prototype;
CollectionProto = BackboneCollection.prototype;
// Built-in Backbone `events`.
defaultEvents = ["change", "add", "remove", "reset", "sort", "destroy"];
collectionEvents = ["reset", "sort"];
Backbone.Associations = {
VERSION: "0.5.4"
};
// Define `getter` and `setter` for `separator`
var getSeparator = function() {
return pathSeparator;
};
// Define `setSeperator`
var setSeparator = function(value) {
if (!_.isString(value) || _.size(value) < 1) {
value = ".";
}
// set private properties
pathSeparator = value;
pathChecker = new RegExp("[\\" + pathSeparator + "\\[\\]]+", "g");
delimiters = new RegExp("[^\\" + pathSeparator + "\\[\\]]+", "g");
};
try {
// Define `SEPERATOR` property to Backbone.Associations
Object.defineProperty(Backbone.Associations, 'SEPARATOR', {
enumerable: true,
get: getSeparator,
set: setSeparator
});
} catch (e) {}
// Backbone.AssociatedModel
// --------------
//Add `Many` and `One` relations to Backbone Object.
Backbone.Associations.Many = Backbone.Many = "Many";
Backbone.Associations.One = Backbone.One = "One";
Backbone.Associations.Self = Backbone.Self = "Self";
// Set default separator
Backbone.Associations.SEPARATOR = ".";
Backbone.Associations.getSeparator = getSeparator;
Backbone.Associations.setSeparator = setSeparator;
setSeparator();
// Define `AssociatedModel` (Extends Backbone.Model).
AssociatedModel = Backbone.AssociatedModel = Backbone.Associations.AssociatedModel = BackboneModel.extend({
// Define relations with Associated Model.
relations:undefined,
// Define `Model` property which can keep track of already fired `events`,
// and prevent redundant event to be triggered in case of cyclic model graphs.
_proxyCalls:undefined,
// Get the value of an attribute.
get:function (attr) {
var obj = ModelProto.get.call(this, attr);
return obj ? obj : this._getAttr.apply(this, arguments);
},
// Set a hash of model attributes on the Backbone Model.
set:function (key, value, options) {
var attributes, result;
// Duplicate backbone's behavior to allow separate key/value parameters,
// instead of a single 'attributes' object.
if (_.isObject(key) || key == null) {
attributes = key;
options = value;
} else {
attributes = {};
attributes[key] = value;
}
result = this._set(attributes, options);
// Trigger events which have been blocked until the entire object graph is updated.
this._processPendingEvents();
return result;
},
// Works with an attribute hash and options + fully qualified paths
_set:function (attributes, options) {
var attr, modelMap, modelId, obj, result = this;
if (!attributes) return this;
for (attr in attributes) {
//Create a map for each unique object whose attributes we want to set
modelMap || (modelMap = {});
if (attr.match(pathChecker)) {
var pathTokens = getPathArray(attr), initials = _.initial(pathTokens),
last = pathTokens[pathTokens.length - 1],
parentModel = this.get(initials);
if (parentModel instanceof AssociatedModel) {
obj = modelMap[parentModel.cid] || (modelMap[parentModel.cid] = {'model':parentModel, 'data':{}});
obj.data[last] = attributes[attr];
}
} else {
obj = modelMap[this.cid] || (modelMap[this.cid] = {'model':this, 'data':{}});
obj.data[attr] = attributes[attr];
}
}
if (modelMap) {
for (modelId in modelMap) {
obj = modelMap[modelId];
this._setAttr.call(obj.model, obj.data, options) || (result = false);
}
} else {
result = this._setAttr.call(this, attributes, options);
}
return result;
},
// Set a hash of model attributes on the object,
// fire Backbone `event` with options.
// It maintains relations between models during the set operation.
// It also bubbles up child events to the parent.
_setAttr:function (attributes, options) {
var attr;
// Extract attributes and options.
options || (options = {});
if (options.unset) for (attr in attributes) attributes[attr] = void 0;
this.parents = this.parents || [];
if (this.relations) {
// Iterate over `this.relations` and `set` model and collection values
// if `relations` are available.
_.each(this.relations, function (relation) {
var relationKey = relation.key,
relatedModel = relation.relatedModel,
collectionType = relation.collectionType,
map = relation.map,
currVal = this.attributes[relationKey],
idKey = currVal && currVal.idAttribute,
val, relationOptions, data, relationValue, newCtx = false;
// Call function if relatedModel is implemented as a function
if (relatedModel && !(relatedModel.prototype instanceof BackboneModel))
relatedModel = _.isFunction(relatedModel) ?
relatedModel.call(this, relation, attributes) :
relatedModel;
// Get class if relation and map is stored as a string.
if (relatedModel && _.isString(relatedModel)) {
relatedModel = (relatedModel === Backbone.Self) ? this.constructor : map2Scope(relatedModel);
}
collectionType && _.isString(collectionType) && (collectionType = map2Scope(collectionType));
map && _.isString(map) && (map = map2Scope(map));
// Merge in `options` specific to this relation.
relationOptions = relation.options ? _.extend({}, relation.options, options) : options;
if ((!relatedModel) && (!collectionType))
throw new Error('specify either a relatedModel or collectionType');
if (attributes[relationKey]) {
// Get value of attribute with relation key in `val`.
val = _.result(attributes, relationKey);
// Map `val` if a transformation function is provided.
val = map ? map.call(this, val, collectionType ? collectionType : relatedModel) : val;
// If `relation.type` is `Backbone.Many`,
// Create `Backbone.Collection` with passed data and perform Backbone `set`.
if (relation.type === Backbone.Many) {
// `collectionType` of defined `relation` should be instance of `Backbone.Collection`.
if (collectionType && !collectionType.prototype instanceof BackboneCollection) {
throw new Error('collectionType must inherit from Backbone.Collection');
}
if (currVal) {
// Setting this flag will prevent events from firing immediately. That way clients
// will not get events until the entire object graph is updated.
currVal._deferEvents = true;
// Use Backbone.Collection's `reset` or smart `set` method
currVal[relationOptions.reset ? 'reset' : 'set'](
val instanceof BackboneCollection ? val.models : val, relationOptions);
data = currVal;
} else {
newCtx = true;
if (val instanceof BackboneCollection) {
data = val;
} else {
data = collectionType ? new collectionType() : this._createCollection(relatedModel);
data[relationOptions.reset ? 'reset' : 'set'](val, relationOptions);
}
}
} else if (relation.type === Backbone.One) {
if (!relatedModel)
throw new Error('specify a relatedModel for Backbone.One type');
if (!(relatedModel.prototype instanceof Backbone.AssociatedModel))
throw new Error('specify an AssociatedModel for Backbone.One type');
data = val instanceof AssociatedModel ? val : new relatedModel(val, relationOptions);
//Is the passed in data for the same key?
if (currVal && data.attributes[idKey] &&
currVal.attributes[idKey] === data.attributes[idKey]) {
// Setting this flag will prevent events from firing immediately. That way clients
// will not get events until the entire object graph is updated.
currVal._deferEvents = true;
// Perform the traditional `set` operation
currVal._set(val instanceof AssociatedModel ? val.attributes : val, relationOptions);
data = currVal;
} else {
newCtx = true;
}
} else {
throw new Error('type attribute must be specified and have the values Backbone.One or Backbone.Many');
}
attributes[relationKey] = data;
relationValue = data;
// Add proxy events to respective parents.
// Only add callback if not defined or new Ctx has been identified.
if (newCtx || (relationValue && !relationValue._proxyCallback)) {
relationValue._proxyCallback = function () {
return this._bubbleEvent.call(this, relationKey, relationValue, arguments);
};
relationValue.on("all", relationValue._proxyCallback, this);
}
}
//Distinguish between the value of undefined versus a set no-op
if (attributes.hasOwnProperty(relationKey)) {
//Maintain reverse pointers - a.k.a parents
var updated = attributes[relationKey];
var original = this.attributes[relationKey];
if (updated) {
updated.parents = updated.parents || [];
(_.indexOf(updated.parents, this) == -1) && updated.parents.push(this);
} else if (original && original.parents.length > 0) { // New value is undefined
original.parents = _.difference(original.parents, [this]);
// Don't bubble to this parent anymore
original._proxyCallback && original.off("all", original._proxyCallback, this);
}
}
}, this);
}
// Return results for `BackboneModel.set`.
return ModelProto.set.call(this, attributes, options);
},
// Bubble-up event to `parent` Model
_bubbleEvent:function (relationKey, relationValue, eventArguments) {
var args = eventArguments,
opt = args[0].split(":"),
eventType = opt[0],
catch_all = args[0] == "nested-change",
eventObject = args[1],
colObject = args[2],
indexEventObject = -1,
_proxyCalls = relationValue._proxyCalls,
cargs,
eventPath,
basecolEventPath,
isDefaultEvent = _.indexOf(defaultEvents, eventType) !== -1;
//Short circuit the listen in to the nested-graph event
if (catch_all) return;
// Change the event name to a fully qualified path.
_.size(opt) > 1 && (eventPath = opt[1]);
if (_.indexOf(collectionEvents, eventType) !== -1) {
colObject = eventObject;
}
// Find the specific object in the collection which has changed.
if (relationValue instanceof BackboneCollection && isDefaultEvent && eventObject) {
var pathTokens = getPathArray(eventPath),
initialTokens = _.initial(pathTokens), colModel;
colModel = relationValue.find(function (model) {
if (eventObject === model) return true;
if (!model) return false;
var changedModel = model.get(initialTokens);
if ((changedModel instanceof AssociatedModel || changedModel instanceof BackboneCollection)
&& eventObject === changedModel)
return true;
changedModel = model.get(pathTokens);
if ((changedModel instanceof AssociatedModel || changedModel instanceof BackboneCollection)
&& eventObject === changedModel)
return true;
if (changedModel instanceof BackboneCollection && colObject
&& colObject === changedModel)
return true;
});
colModel && (indexEventObject = relationValue.indexOf(colModel));
}
// Manipulate `eventPath`.
eventPath = relationKey + ((indexEventObject !== -1 && (eventType === "change" || eventPath)) ?
"[" + indexEventObject + "]" : "") + (eventPath ? pathSeparator + eventPath : "");
// Short circuit collection * events
if (/\[\*\]/g.test(eventPath)) return this;
basecolEventPath = eventPath.replace(/\[\d+\]/g, '[*]');
cargs = [];
cargs.push.apply(cargs, args);
cargs[0] = eventType + ":" + eventPath;
// If event has been already triggered as result of same source `eventPath`,
// no need to re-trigger event to prevent cycle.
_proxyCalls = relationValue._proxyCalls = (_proxyCalls || {});
if (this._isEventAvailable.call(this, _proxyCalls, eventPath)) return this;
// Add `eventPath` in `_proxyCalls` to keep track of already triggered `event`.
_proxyCalls[eventPath] = true;
// Set up previous attributes correctly.
if ("change" === eventType) {
this._previousAttributes[relationKey] = relationValue._previousAttributes;
this.changed[relationKey] = relationValue;
}
// Bubble up event to parent `model` with new changed arguments.
this.trigger.apply(this, cargs);
//Only fire for change. Not change:attribute
if ("change" === eventType && this.get(eventPath) != args[2]) {
var ncargs = ["nested-change", eventPath, args[1]];
args[2] && ncargs.push(args[2]); //args[2] will be options if present
this.trigger.apply(this, ncargs);
}
// Remove `eventPath` from `_proxyCalls`,
// if `eventPath` and `_proxyCalls` are available,
// which allow event to be triggered on for next operation of `set`.
if (_proxyCalls && eventPath) delete _proxyCalls[eventPath];
// Create a collection modified event with wild-card
if (eventPath !== basecolEventPath) {
cargs[0] = eventType + ":" + basecolEventPath;
this.trigger.apply(this, cargs);
}
return this;
},
// Has event been fired from this source. Used to prevent event recursion in cyclic graphs
_isEventAvailable:function (_proxyCalls, path) {
return _.find(_proxyCalls, function (value, eventKey) {
return path.indexOf(eventKey, path.length - eventKey.length) !== -1;
});
},
// Returns New `collection` of type `relation.relatedModel`.
_createCollection:function (type) {
var collection, relatedModel = type;
_.isString(relatedModel) && (relatedModel = map2Scope(relatedModel));
// Creates new `Backbone.Collection` and defines model class.
if (relatedModel && (relatedModel.prototype instanceof AssociatedModel) || _.isFunction(relatedModel)) {
collection = new BackboneCollection();
collection.model = relatedModel;
} else {
throw new Error('type must inherit from Backbone.AssociatedModel');
}
return collection;
},
// Process all pending events after the entire object graph has been updated
_processPendingEvents:function () {
if (!this._processedEvents) {
this._processedEvents = true;
this._deferEvents = false;
// Trigger all pending events
_.each(this._pendingEvents, function (e) {
e.c.trigger.apply(e.c, e.a);
});
this._pendingEvents = [];
// Traverse down the object graph and call process pending events on sub-trees
_.each(this.relations, function (relation) {
var val = this.attributes[relation.key];
val && val._processPendingEvents();
}, this);
delete this._processedEvents;
}
},
// Override trigger to defer events in the object graph.
trigger:function (name) {
// Defer event processing
if (this._deferEvents) {
this._pendingEvents = this._pendingEvents || [];
// Maintain a queue of pending events to trigger after the entire object graph is updated.
this._pendingEvents.push({c:this, a:arguments});
} else {
ModelProto.trigger.apply(this, arguments);
}
},
// The JSON representation of the model.
toJSON:function (options) {
var json = {}, aJson;
json[this.idAttribute] = this.id;
if (!this.visited) {
this.visited = true;
// Get json representation from `BackboneModel.toJSON`.
json = ModelProto.toJSON.apply(this, arguments);
// If `this.relations` is defined, iterate through each `relation`
// and added it's json representation to parents' json representation.
if (this.relations) {
_.each(this.relations, function (relation) {
var attr = this.attributes[relation.key];
if (attr) {
aJson = attr.toJSON ? attr.toJSON(options) : attr;
json[relation.key] = _.isArray(aJson) ? _.compact(aJson) : aJson;
}
}, this);
}
delete this.visited;
}
return json;
},
// Create a new model with identical attributes to this one.
clone:function () {
return new this.constructor(this.toJSON());
},
// Call this if you want to set an `AssociatedModel` to a falsy value like undefined/null directly.
// Not calling this will leak memory and have wrong parents.
// See test case "parent relations"
cleanup:function () {
_.each(this.relations, function (relation) {
var val = this.attributes[relation.key];
val && (val.parents = _.difference(val.parents, [this]));
}, this);
this.off();
},
// Navigate the path to the leaf object in the path to query for the attribute value
_getAttr:function (path) {
var result = this,
//Tokenize the path
attrs = getPathArray(path),
key,
i;
if (_.size(attrs) < 1) return;
for (i = 0; i < attrs.length; i++) {
key = attrs[i];
if (!result) break;
//Navigate the path to get to the result
result = result instanceof BackboneCollection
? (isNaN(key) ? undefined : result.at(key))
: result.attributes[key];
}
return result;
}
});
// Tokenize the fully qualified event path
var getPathArray = function (path) {
if (path === '') return [''];
return _.isString(path) ? (path.match(delimiters)) : path || [];
};
var map2Scope = function (path) {
return _.reduce(path.split(pathSeparator), function (memo, elem) {
return memo[elem];
}, root);
};
//Infer the relation from the collection's parents and find the appropriate map for the passed in `models`
var map2models = function (parents, target, models) {
var relation, surrogate;
//Iterate over collection's parents
_.find(parents, function (parent) {
//Iterate over relations
relation = _.find(parent.relations, function (rel) {
return parent.get(rel.key) === target;
}, this);
if (relation) {
surrogate = parent;//surrogate for transformation
return true;//break;
}
}, this);
//If we found a relation and it has a mapping function
if (relation && relation.map) {
return relation.map.call(surrogate, models, target);
}
return models;
};
var proxies = {};
// Proxy Backbone collection methods
_.each(['set', 'remove', 'reset'], function (method) {
proxies[method] = BackboneCollection.prototype[method];
CollectionProto[method] = function (models, options) {
//Short-circuit if this collection doesn't hold `AssociatedModels`
if (this.model.prototype instanceof AssociatedModel && this.parents) {
//Find a map function if available and perform a transformation
arguments[0] = map2models(this.parents, this, models);
}
return proxies[method].apply(this, arguments);
}
});
// Override trigger to defer events in the object graph.
proxies['trigger'] = CollectionProto['trigger'];
CollectionProto['trigger'] = function (name) {
if (this._deferEvents) {
this._pendingEvents = this._pendingEvents || [];
// Maintain a queue of pending events to trigger after the entire object graph is updated.
this._pendingEvents.push({c:this, a:arguments});
} else {
proxies['trigger'].apply(this, arguments);
}
};
// Attach process pending event functionality on collections as well. Re-use from `AssociatedModel`
CollectionProto._processPendingEvents = AssociatedModel.prototype._processPendingEvents;
}).call(this);