server/php/basic/public_html/static/lib/backbone-relational/backbone-relational.js
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     1 /* vim: set tabstop=4 softtabstop=4 shiftwidth=4 noexpandtab: */
       
     2 /**
       
     3  * Backbone-relational.js 0.9.0
       
     4  * (c) 2011-2014 Paul Uithol and contributors (https://github.com/PaulUithol/Backbone-relational/graphs/contributors)
       
     5  *
       
     6  * Backbone-relational may be freely distributed under the MIT license; see the accompanying LICENSE.txt.
       
     7  * For details and documentation: https://github.com/PaulUithol/Backbone-relational.
       
     8  * Depends on Backbone (and thus on Underscore as well): https://github.com/documentcloud/backbone.
       
     9  *
       
    10  * Example:
       
    11  *
       
    12 	Zoo = Backbone.RelationalModel.extend({
       
    13 		relations: [ {
       
    14 			type: Backbone.HasMany,
       
    15 			key: 'animals',
       
    16 			relatedModel: 'Animal',
       
    17 			reverseRelation: {
       
    18 				key: 'livesIn',
       
    19 				includeInJSON: 'id'
       
    20 				// 'relatedModel' is automatically set to 'Zoo'; the 'relationType' to 'HasOne'.
       
    21 			}
       
    22 		} ],
       
    23 
       
    24 		toString: function() {
       
    25 			return this.get( 'name' );
       
    26 		}
       
    27 	});
       
    28 
       
    29 	Animal = Backbone.RelationalModel.extend({
       
    30 		toString: function() {
       
    31 			return this.get( 'species' );
       
    32 		}
       
    33 	});
       
    34 
       
    35 	// Creating the zoo will give it a collection with one animal in it: the monkey.
       
    36 	// The animal created after that has a relation `livesIn` that points to the zoo it's currently associated with.
       
    37 	// If you instantiate (or fetch) the zebra later, it will automatically be added.
       
    38 
       
    39 	var zoo = new Zoo({
       
    40 		name: 'Artis',
       
    41 		animals: [ { id: 'monkey-1', species: 'Chimp' }, 'lion-1', 'zebra-1' ]
       
    42 	});
       
    43 
       
    44 	var lion = new Animal( { id: 'lion-1', species: 'Lion' } ),
       
    45 		monkey = zoo.get( 'animals' ).first(),
       
    46 		sameZoo = lion.get( 'livesIn' );
       
    47  */
       
    48 ( function( root, factory ) {
       
    49 	// Set up Backbone-relational for the environment. Start with AMD.
       
    50 	if ( typeof define === 'function' && define.amd ) {
       
    51 		define( [ 'exports', 'backbone', 'underscore' ], factory );
       
    52 	}
       
    53 	// Next for Node.js or CommonJS.
       
    54 	else if ( typeof exports !== 'undefined' ) {
       
    55 		factory( exports, require( 'backbone' ), require( 'underscore' ) );
       
    56 	}
       
    57 	// Finally, as a browser global. Use `root` here as it references `window`.
       
    58 	else {
       
    59 		factory( root, root.Backbone, root._ );
       
    60 	}
       
    61 }( this, function( exports, Backbone, _ ) {
       
    62 	"use strict";
       
    63 
       
    64 	Backbone.Relational = {
       
    65 		showWarnings: true
       
    66 	};
       
    67 
       
    68 	/**
       
    69 	 * Semaphore mixin; can be used as both binary and counting.
       
    70 	 **/
       
    71 	Backbone.Semaphore = {
       
    72 		_permitsAvailable: null,
       
    73 		_permitsUsed: 0,
       
    74 
       
    75 		acquire: function() {
       
    76 			if ( this._permitsAvailable && this._permitsUsed >= this._permitsAvailable ) {
       
    77 				throw new Error( 'Max permits acquired' );
       
    78 			}
       
    79 			else {
       
    80 				this._permitsUsed++;
       
    81 			}
       
    82 		},
       
    83 
       
    84 		release: function() {
       
    85 			if ( this._permitsUsed === 0 ) {
       
    86 				throw new Error( 'All permits released' );
       
    87 			}
       
    88 			else {
       
    89 				this._permitsUsed--;
       
    90 			}
       
    91 		},
       
    92 
       
    93 		isLocked: function() {
       
    94 			return this._permitsUsed > 0;
       
    95 		},
       
    96 
       
    97 		setAvailablePermits: function( amount ) {
       
    98 			if ( this._permitsUsed > amount ) {
       
    99 				throw new Error( 'Available permits cannot be less than used permits' );
       
   100 			}
       
   101 			this._permitsAvailable = amount;
       
   102 		}
       
   103 	};
       
   104 
       
   105 	/**
       
   106 	 * A BlockingQueue that accumulates items while blocked (via 'block'),
       
   107 	 * and processes them when unblocked (via 'unblock').
       
   108 	 * Process can also be called manually (via 'process').
       
   109 	 */
       
   110 	Backbone.BlockingQueue = function() {
       
   111 		this._queue = [];
       
   112 	};
       
   113 	_.extend( Backbone.BlockingQueue.prototype, Backbone.Semaphore, {
       
   114 		_queue: null,
       
   115 
       
   116 		add: function( func ) {
       
   117 			if ( this.isBlocked() ) {
       
   118 				this._queue.push( func );
       
   119 			}
       
   120 			else {
       
   121 				func();
       
   122 			}
       
   123 		},
       
   124 
       
   125 		// Some of the queued events may trigger other blocking events. By
       
   126 		// copying the queue here it allows queued events to process closer to
       
   127 		// the natural order.
       
   128 		//
       
   129 		// queue events [ 'A', 'B', 'C' ]
       
   130 		// A handler of 'B' triggers 'D' and 'E'
       
   131 		// By copying `this._queue` this executes:
       
   132 		// [ 'A', 'B', 'D', 'E', 'C' ]
       
   133 		// The same order the would have executed if they didn't have to be
       
   134 		// delayed and queued.
       
   135 		process: function() {
       
   136 			var queue = this._queue;
       
   137 			this._queue = [];
       
   138 			while ( queue && queue.length ) {
       
   139 				queue.shift()();
       
   140 			}
       
   141 		},
       
   142 
       
   143 		block: function() {
       
   144 			this.acquire();
       
   145 		},
       
   146 
       
   147 		unblock: function() {
       
   148 			this.release();
       
   149 			if ( !this.isBlocked() ) {
       
   150 				this.process();
       
   151 			}
       
   152 		},
       
   153 
       
   154 		isBlocked: function() {
       
   155 			return this.isLocked();
       
   156 		}
       
   157 	});
       
   158 	/**
       
   159 	 * Global event queue. Accumulates external events ('add:<key>', 'remove:<key>' and 'change:<key>')
       
   160 	 * until the top-level object is fully initialized (see 'Backbone.RelationalModel').
       
   161 	 */
       
   162 	Backbone.Relational.eventQueue = new Backbone.BlockingQueue();
       
   163 
       
   164 	/**
       
   165 	 * Backbone.Store keeps track of all created (and destruction of) Backbone.RelationalModel.
       
   166 	 * Handles lookup for relations.
       
   167 	 */
       
   168 	Backbone.Store = function() {
       
   169 		this._collections = [];
       
   170 		this._reverseRelations = [];
       
   171 		this._orphanRelations = [];
       
   172 		this._subModels = [];
       
   173 		this._modelScopes = [ exports ];
       
   174 	};
       
   175 	_.extend( Backbone.Store.prototype, Backbone.Events, {
       
   176 		/**
       
   177 		 * Create a new `Relation`.
       
   178 		 * @param {Backbone.RelationalModel} [model]
       
   179 		 * @param {Object} relation
       
   180 		 * @param {Object} [options]
       
   181 		 */
       
   182 		initializeRelation: function( model, relation, options ) {
       
   183 			var type = !_.isString( relation.type ) ? relation.type : Backbone[ relation.type ] || this.getObjectByName( relation.type );
       
   184 			if ( type && type.prototype instanceof Backbone.Relation ) {
       
   185 				var rel = new type( model, relation, options ); // Also pushes the new Relation into `model._relations`
       
   186 			}
       
   187 			else {
       
   188 				Backbone.Relational.showWarnings && typeof console !== 'undefined' && console.warn( 'Relation=%o; missing or invalid relation type!', relation );
       
   189 			}
       
   190 		},
       
   191 
       
   192 		/**
       
   193 		 * Add a scope for `getObjectByName` to look for model types by name.
       
   194 		 * @param {Object} scope
       
   195 		 */
       
   196 		addModelScope: function( scope ) {
       
   197 			this._modelScopes.push( scope );
       
   198 		},
       
   199 
       
   200 		/**
       
   201 		 * Remove a scope.
       
   202 		 * @param {Object} scope
       
   203 		 */
       
   204 		removeModelScope: function( scope ) {
       
   205 			this._modelScopes = _.without( this._modelScopes, scope );
       
   206 		},
       
   207 
       
   208 		/**
       
   209 		 * Add a set of subModelTypes to the store, that can be used to resolve the '_superModel'
       
   210 		 * for a model later in 'setupSuperModel'.
       
   211 		 *
       
   212 		 * @param {Backbone.RelationalModel} subModelTypes
       
   213 		 * @param {Backbone.RelationalModel} superModelType
       
   214 		 */
       
   215 		addSubModels: function( subModelTypes, superModelType ) {
       
   216 			this._subModels.push({
       
   217 				'superModelType': superModelType,
       
   218 				'subModels': subModelTypes
       
   219 			});
       
   220 		},
       
   221 
       
   222 		/**
       
   223 		 * Check if the given modelType is registered as another model's subModel. If so, add it to the super model's
       
   224 		 * '_subModels', and set the modelType's '_superModel', '_subModelTypeName', and '_subModelTypeAttribute'.
       
   225 		 *
       
   226 		 * @param {Backbone.RelationalModel} modelType
       
   227 		 */
       
   228 		setupSuperModel: function( modelType ) {
       
   229 			_.find( this._subModels, function( subModelDef ) {
       
   230 				return _.filter( subModelDef.subModels || [], function( subModelTypeName, typeValue ) {
       
   231 					var subModelType = this.getObjectByName( subModelTypeName );
       
   232 
       
   233 					if ( modelType === subModelType ) {
       
   234 						// Set 'modelType' as a child of the found superModel
       
   235 						subModelDef.superModelType._subModels[ typeValue ] = modelType;
       
   236 
       
   237 						// Set '_superModel', '_subModelTypeValue', and '_subModelTypeAttribute' on 'modelType'.
       
   238 						modelType._superModel = subModelDef.superModelType;
       
   239 						modelType._subModelTypeValue = typeValue;
       
   240 						modelType._subModelTypeAttribute = subModelDef.superModelType.prototype.subModelTypeAttribute;
       
   241 						return true;
       
   242 					}
       
   243 				}, this ).length;
       
   244 			}, this );
       
   245 		},
       
   246 
       
   247 		/**
       
   248 		 * Add a reverse relation. Is added to the 'relations' property on model's prototype, and to
       
   249 		 * existing instances of 'model' in the store as well.
       
   250 		 * @param {Object} relation
       
   251 		 * @param {Backbone.RelationalModel} relation.model
       
   252 		 * @param {String} relation.type
       
   253 		 * @param {String} relation.key
       
   254 		 * @param {String|Object} relation.relatedModel
       
   255 		 */
       
   256 		addReverseRelation: function( relation ) {
       
   257 			var exists = _.any( this._reverseRelations, function( rel ) {
       
   258 				return _.all( relation || [], function( val, key ) {
       
   259 					return val === rel[ key ];
       
   260 				});
       
   261 			});
       
   262 
       
   263 			if ( !exists && relation.model && relation.type ) {
       
   264 				this._reverseRelations.push( relation );
       
   265 				this._addRelation( relation.model, relation );
       
   266 				this.retroFitRelation( relation );
       
   267 			}
       
   268 		},
       
   269 
       
   270 		/**
       
   271 		 * Deposit a `relation` for which the `relatedModel` can't be resolved at the moment.
       
   272 		 *
       
   273 		 * @param {Object} relation
       
   274 		 */
       
   275 		addOrphanRelation: function( relation ) {
       
   276 			var exists = _.any( this._orphanRelations, function( rel ) {
       
   277 				return _.all( relation || [], function( val, key ) {
       
   278 					return val === rel[ key ];
       
   279 				});
       
   280 			});
       
   281 
       
   282 			if ( !exists && relation.model && relation.type ) {
       
   283 				this._orphanRelations.push( relation );
       
   284 			}
       
   285 		},
       
   286 
       
   287 		/**
       
   288 		 * Try to initialize any `_orphanRelation`s
       
   289 		 */
       
   290 		processOrphanRelations: function() {
       
   291 			// Make sure to operate on a copy since we're removing while iterating
       
   292 			_.each( this._orphanRelations.slice( 0 ), function( rel ) {
       
   293 				var relatedModel = Backbone.Relational.store.getObjectByName( rel.relatedModel );
       
   294 				if ( relatedModel ) {
       
   295 					this.initializeRelation( null, rel );
       
   296 					this._orphanRelations = _.without( this._orphanRelations, rel );
       
   297 				}
       
   298 			}, this );
       
   299 		},
       
   300 
       
   301 		/**
       
   302 		 *
       
   303 		 * @param {Backbone.RelationalModel.constructor} type
       
   304 		 * @param {Object} relation
       
   305 		 * @private
       
   306 		 */
       
   307 		_addRelation: function( type, relation ) {
       
   308 			if ( !type.prototype.relations ) {
       
   309 				type.prototype.relations = [];
       
   310 			}
       
   311 			type.prototype.relations.push( relation );
       
   312 
       
   313 			_.each( type._subModels || [], function( subModel ) {
       
   314 				this._addRelation( subModel, relation );
       
   315 			}, this );
       
   316 		},
       
   317 
       
   318 		/**
       
   319 		 * Add a 'relation' to all existing instances of 'relation.model' in the store
       
   320 		 * @param {Object} relation
       
   321 		 */
       
   322 		retroFitRelation: function( relation ) {
       
   323 			var coll = this.getCollection( relation.model, false );
       
   324 			coll && coll.each( function( model ) {
       
   325 				if ( !( model instanceof relation.model ) ) {
       
   326 					return;
       
   327 				}
       
   328 
       
   329 				var rel = new relation.type( model, relation );
       
   330 			}, this );
       
   331 		},
       
   332 
       
   333 		/**
       
   334 		 * Find the Store's collection for a certain type of model.
       
   335 		 * @param {Backbone.RelationalModel} type
       
   336 		 * @param {Boolean} [create=true] Should a collection be created if none is found?
       
   337 		 * @return {Backbone.Collection} A collection if found (or applicable for 'model'), or null
       
   338 		 */
       
   339 		getCollection: function( type, create ) {
       
   340 			if ( type instanceof Backbone.RelationalModel ) {
       
   341 				type = type.constructor;
       
   342 			}
       
   343 
       
   344 			var rootModel = type;
       
   345 			while ( rootModel._superModel ) {
       
   346 				rootModel = rootModel._superModel;
       
   347 			}
       
   348 
       
   349 			var coll = _.find( this._collections, function( item ) {
       
   350 				return item.model === rootModel;
       
   351 			});
       
   352 
       
   353 			if ( !coll && create !== false ) {
       
   354 				coll = this._createCollection( rootModel );
       
   355 			}
       
   356 
       
   357 			return coll;
       
   358 		},
       
   359 
       
   360 		/**
       
   361 		 * Find a model type on one of the modelScopes by name. Names are split on dots.
       
   362 		 * @param {String} name
       
   363 		 * @return {Object}
       
   364 		 */
       
   365 		getObjectByName: function( name ) {
       
   366 			var parts = name.split( '.' ),
       
   367 				type = null;
       
   368 
       
   369 			_.find( this._modelScopes, function( scope ) {
       
   370 				type = _.reduce( parts || [], function( memo, val ) {
       
   371 					return memo ? memo[ val ] : undefined;
       
   372 				}, scope );
       
   373 
       
   374 				if ( type && type !== scope ) {
       
   375 					return true;
       
   376 				}
       
   377 			}, this );
       
   378 
       
   379 			return type;
       
   380 		},
       
   381 
       
   382 		_createCollection: function( type ) {
       
   383 			var coll;
       
   384 
       
   385 			// If 'type' is an instance, take its constructor
       
   386 			if ( type instanceof Backbone.RelationalModel ) {
       
   387 				type = type.constructor;
       
   388 			}
       
   389 
       
   390 			// Type should inherit from Backbone.RelationalModel.
       
   391 			if ( type.prototype instanceof Backbone.RelationalModel ) {
       
   392 				coll = new Backbone.Collection();
       
   393 				coll.model = type;
       
   394 
       
   395 				this._collections.push( coll );
       
   396 			}
       
   397 
       
   398 			return coll;
       
   399 		},
       
   400 
       
   401 		/**
       
   402 		 * Find the attribute that is to be used as the `id` on a given object
       
   403 		 * @param type
       
   404 		 * @param {String|Number|Object|Backbone.RelationalModel} item
       
   405 		 * @return {String|Number}
       
   406 		 */
       
   407 		resolveIdForItem: function( type, item ) {
       
   408 			var id = _.isString( item ) || _.isNumber( item ) ? item : null;
       
   409 
       
   410 			if ( id === null ) {
       
   411 				if ( item instanceof Backbone.RelationalModel ) {
       
   412 					id = item.id;
       
   413 				}
       
   414 				else if ( _.isObject( item ) ) {
       
   415 					id = item[ type.prototype.idAttribute ];
       
   416 				}
       
   417 			}
       
   418 
       
   419 			// Make all falsy values `null` (except for 0, which could be an id.. see '/issues/179')
       
   420 			if ( !id && id !== 0 ) {
       
   421 				id = null;
       
   422 			}
       
   423 
       
   424 			return id;
       
   425 		},
       
   426 
       
   427 		/**
       
   428 		 * Find a specific model of a certain `type` in the store
       
   429 		 * @param type
       
   430 		 * @param {String|Number|Object|Backbone.RelationalModel} item
       
   431 		 */
       
   432 		find: function( type, item ) {
       
   433 			var id = this.resolveIdForItem( type, item ),
       
   434 				coll = this.getCollection( type );
       
   435 
       
   436 			// Because the found object could be of any of the type's superModel
       
   437 			// types, only return it if it's actually of the type asked for.
       
   438 			if ( coll ) {
       
   439 				var obj = coll.get( id );
       
   440 
       
   441 				if ( obj instanceof type ) {
       
   442 					return obj;
       
   443 				}
       
   444 			}
       
   445 
       
   446 			return null;
       
   447 		},
       
   448 
       
   449 		/**
       
   450 		 * Add a 'model' to its appropriate collection. Retain the original contents of 'model.collection'.
       
   451 		 * @param {Backbone.RelationalModel} model
       
   452 		 */
       
   453 		register: function( model ) {
       
   454 			var coll = this.getCollection( model );
       
   455 
       
   456 			if ( coll ) {
       
   457 				var modelColl = model.collection;
       
   458 				coll.add( model );
       
   459 				model.collection = modelColl;
       
   460 			}
       
   461 		},
       
   462 
       
   463 		/**
       
   464 		 * Check if the given model may use the given `id`
       
   465 		 * @param model
       
   466 		 * @param [id]
       
   467 		 */
       
   468 		checkId: function( model, id ) {
       
   469 			var coll = this.getCollection( model ),
       
   470 				duplicate = coll && coll.get( id );
       
   471 
       
   472 			if ( duplicate && model !== duplicate ) {
       
   473 				if ( Backbone.Relational.showWarnings && typeof console !== 'undefined' ) {
       
   474 					console.warn( 'Duplicate id! Old RelationalModel=%o, new RelationalModel=%o', duplicate, model );
       
   475 				}
       
   476 
       
   477 				throw new Error( "Cannot instantiate more than one Backbone.RelationalModel with the same id per type!" );
       
   478 			}
       
   479 		},
       
   480 
       
   481 		/**
       
   482 		 * Explicitly update a model's id in its store collection
       
   483 		 * @param {Backbone.RelationalModel} model
       
   484 		 */
       
   485 		update: function( model ) {
       
   486 			var coll = this.getCollection( model );
       
   487 
       
   488 			// Register a model if it isn't yet (which happens if it was created without an id).
       
   489 			if ( !coll.contains( model ) ) {
       
   490 				this.register( model );
       
   491 			}
       
   492 
       
   493 			// This triggers updating the lookup indices kept in a collection
       
   494 			coll._onModelEvent( 'change:' + model.idAttribute, model, coll );
       
   495 
       
   496 			// Trigger an event on model so related models (having the model's new id in their keyContents) can add it.
       
   497 			model.trigger( 'relational:change:id', model, coll );
       
   498 		},
       
   499 
       
   500 		/**
       
   501 		 * Unregister from the store: a specific model, a collection, or a model type.
       
   502 		 * @param {Backbone.RelationalModel|Backbone.RelationalModel.constructor|Backbone.Collection} type
       
   503 		 */
       
   504 		unregister: function( type ) {
       
   505 			var coll,
       
   506 				models;
       
   507 
       
   508 			if ( type instanceof Backbone.Model ) {
       
   509 				coll = this.getCollection( type );
       
   510 				models = [ type ];
       
   511 			}
       
   512 			else if ( type instanceof Backbone.Collection ) {
       
   513 				coll = this.getCollection( type.model );
       
   514 				models = _.clone( type.models );
       
   515 			}
       
   516 			else {
       
   517 				coll = this.getCollection( type );
       
   518 				models = _.clone( coll.models );
       
   519 			}
       
   520 
       
   521 			_.each( models, function( model ) {
       
   522 				this.stopListening( model );
       
   523 				_.invoke( model.getRelations(), 'stopListening' );
       
   524 			}, this );
       
   525 
       
   526 
       
   527 			// If we've unregistered an entire store collection, reset the collection (which is much faster).
       
   528 			// Otherwise, remove each model one by one.
       
   529 			if ( _.contains( this._collections, type ) ) {
       
   530 				coll.reset( [] );
       
   531 			}
       
   532 			else {
       
   533 				_.each( models, function( model ) {
       
   534 					if ( coll.get( model ) ) {
       
   535 						coll.remove( model );
       
   536 					}
       
   537 					else {
       
   538 						coll.trigger( 'relational:remove', model, coll );
       
   539 					}
       
   540 				}, this );
       
   541 			}
       
   542 		},
       
   543 
       
   544 		/**
       
   545 		 * Reset the `store` to it's original state. The `reverseRelations` are kept though, since attempting to
       
   546 		 * re-initialize these on models would lead to a large amount of warnings.
       
   547 		 */
       
   548 		reset: function() {
       
   549 			this.stopListening();
       
   550 
       
   551 			// Unregister each collection to remove event listeners
       
   552 			_.each( this._collections, function( coll ) {
       
   553 				this.unregister( coll );
       
   554 			}, this );
       
   555 
       
   556 			this._collections = [];
       
   557 			this._subModels = [];
       
   558 			this._modelScopes = [ exports ];
       
   559 		}
       
   560 	});
       
   561 	Backbone.Relational.store = new Backbone.Store();
       
   562 
       
   563 	/**
       
   564 	 * The main Relation class, from which 'HasOne' and 'HasMany' inherit. Internally, 'relational:<key>' events
       
   565 	 * are used to regulate addition and removal of models from relations.
       
   566 	 *
       
   567 	 * @param {Backbone.RelationalModel} [instance] Model that this relation is created for. If no model is supplied,
       
   568 	 *      Relation just tries to instantiate it's `reverseRelation` if specified, and bails out after that.
       
   569 	 * @param {Object} options
       
   570 	 * @param {string} options.key
       
   571 	 * @param {Backbone.RelationalModel.constructor} options.relatedModel
       
   572 	 * @param {Boolean|String} [options.includeInJSON=true] Serialize the given attribute for related model(s)' in toJSON, or just their ids.
       
   573 	 * @param {Boolean} [options.createModels=true] Create objects from the contents of keys if the object is not found in Backbone.store.
       
   574 	 * @param {Object} [options.reverseRelation] Specify a bi-directional relation. If provided, Relation will reciprocate
       
   575 	 *    the relation to the 'relatedModel'. Required and optional properties match 'options', except that it also needs
       
   576 	 *    {Backbone.Relation|String} type ('HasOne' or 'HasMany').
       
   577 	 * @param {Object} opts
       
   578 	 */
       
   579 	Backbone.Relation = function( instance, options, opts ) {
       
   580 		this.instance = instance;
       
   581 		// Make sure 'options' is sane, and fill with defaults from subclasses and this object's prototype
       
   582 		options = _.isObject( options ) ? options : {};
       
   583 		this.reverseRelation = _.defaults( options.reverseRelation || {}, this.options.reverseRelation );
       
   584 		this.options = _.defaults( options, this.options, Backbone.Relation.prototype.options );
       
   585 
       
   586 		this.reverseRelation.type = !_.isString( this.reverseRelation.type ) ? this.reverseRelation.type :
       
   587 			Backbone[ this.reverseRelation.type ] || Backbone.Relational.store.getObjectByName( this.reverseRelation.type );
       
   588 
       
   589 		this.key = this.options.key;
       
   590 		this.keySource = this.options.keySource || this.key;
       
   591 		this.keyDestination = this.options.keyDestination || this.keySource || this.key;
       
   592 
       
   593 		this.model = this.options.model || this.instance.constructor;
       
   594 
       
   595 		this.relatedModel = this.options.relatedModel;
       
   596 
       
   597 		// No 'relatedModel' is interpreted as self-referential
       
   598 		if ( _.isUndefined( this.relatedModel ) ) {
       
   599 			this.relatedModel = this.model;
       
   600 		}
       
   601 
       
   602 		// Otherwise, try to resolve the given value to an object
       
   603 		if ( _.isFunction( this.relatedModel ) && !( this.relatedModel.prototype instanceof Backbone.RelationalModel ) ) {
       
   604 			this.relatedModel = _.result( this, 'relatedModel' );
       
   605 		}
       
   606 		if ( _.isString( this.relatedModel ) ) {
       
   607 			this.relatedModel = Backbone.Relational.store.getObjectByName( this.relatedModel );
       
   608 		}
       
   609 
       
   610 
       
   611 		if ( !this.checkPreconditions() ) {
       
   612 			return;
       
   613 		}
       
   614 
       
   615 		// Add the reverse relation on 'relatedModel' to the store's reverseRelations
       
   616 		if ( !this.options.isAutoRelation && this.reverseRelation.type && this.reverseRelation.key ) {
       
   617 			Backbone.Relational.store.addReverseRelation( _.defaults( {
       
   618 					isAutoRelation: true,
       
   619 					model: this.relatedModel,
       
   620 					relatedModel: this.model,
       
   621 					reverseRelation: this.options // current relation is the 'reverseRelation' for its own reverseRelation
       
   622 				},
       
   623 				this.reverseRelation // Take further properties from this.reverseRelation (type, key, etc.)
       
   624 			) );
       
   625 		}
       
   626 
       
   627 		if ( instance ) {
       
   628 			var contentKey = this.keySource;
       
   629 			if ( contentKey !== this.key && _.isObject( this.instance.get( this.key ) ) ) {
       
   630 				contentKey = this.key;
       
   631 			}
       
   632 
       
   633 			this.setKeyContents( this.instance.get( contentKey ) );
       
   634 			this.relatedCollection = Backbone.Relational.store.getCollection( this.relatedModel );
       
   635 
       
   636 			// Explicitly clear 'keySource', to prevent a leaky abstraction if 'keySource' differs from 'key'.
       
   637 			if ( this.keySource !== this.key ) {
       
   638 				delete this.instance.attributes[ this.keySource ];
       
   639 			}
       
   640 
       
   641 			// Add this Relation to instance._relations
       
   642 			this.instance._relations[ this.key ] = this;
       
   643 
       
   644 			this.initialize( opts );
       
   645 
       
   646 			if ( this.options.autoFetch ) {
       
   647 				this.instance.getAsync( this.key, _.isObject( this.options.autoFetch ) ? this.options.autoFetch : {} );
       
   648 			}
       
   649 
       
   650 			// When 'relatedModel' are created or destroyed, check if it affects this relation.
       
   651 			this.listenTo( this.instance, 'destroy', this.destroy )
       
   652 				.listenTo( this.relatedCollection, 'relational:add relational:change:id', this.tryAddRelated )
       
   653 				.listenTo( this.relatedCollection, 'relational:remove', this.removeRelated );
       
   654 		}
       
   655 	};
       
   656 	// Fix inheritance :\
       
   657 	Backbone.Relation.extend = Backbone.Model.extend;
       
   658 	// Set up all inheritable **Backbone.Relation** properties and methods.
       
   659 	_.extend( Backbone.Relation.prototype, Backbone.Events, Backbone.Semaphore, {
       
   660 		options: {
       
   661 			createModels: true,
       
   662 			includeInJSON: true,
       
   663 			isAutoRelation: false,
       
   664 			autoFetch: false,
       
   665 			parse: false
       
   666 		},
       
   667 
       
   668 		instance: null,
       
   669 		key: null,
       
   670 		keyContents: null,
       
   671 		relatedModel: null,
       
   672 		relatedCollection: null,
       
   673 		reverseRelation: null,
       
   674 		related: null,
       
   675 
       
   676 		/**
       
   677 		 * Check several pre-conditions.
       
   678 		 * @return {Boolean} True if pre-conditions are satisfied, false if they're not.
       
   679 		 */
       
   680 		checkPreconditions: function() {
       
   681 			var i = this.instance,
       
   682 				k = this.key,
       
   683 				m = this.model,
       
   684 				rm = this.relatedModel,
       
   685 				warn = Backbone.Relational.showWarnings && typeof console !== 'undefined';
       
   686 
       
   687 			if ( !m || !k || !rm ) {
       
   688 				warn && console.warn( 'Relation=%o: missing model, key or relatedModel (%o, %o, %o).', this, m, k, rm );
       
   689 				return false;
       
   690 			}
       
   691 			// Check if the type in 'model' inherits from Backbone.RelationalModel
       
   692 			if ( !( m.prototype instanceof Backbone.RelationalModel ) ) {
       
   693 				warn && console.warn( 'Relation=%o: model does not inherit from Backbone.RelationalModel (%o).', this, i );
       
   694 				return false;
       
   695 			}
       
   696 			// Check if the type in 'relatedModel' inherits from Backbone.RelationalModel
       
   697 			if ( !( rm.prototype instanceof Backbone.RelationalModel ) ) {
       
   698 				warn && console.warn( 'Relation=%o: relatedModel does not inherit from Backbone.RelationalModel (%o).', this, rm );
       
   699 				return false;
       
   700 			}
       
   701 			// Check if this is not a HasMany, and the reverse relation is HasMany as well
       
   702 			if ( this instanceof Backbone.HasMany && this.reverseRelation.type === Backbone.HasMany ) {
       
   703 				warn && console.warn( 'Relation=%o: relation is a HasMany, and the reverseRelation is HasMany as well.', this );
       
   704 				return false;
       
   705 			}
       
   706 			// Check if we're not attempting to create a relationship on a `key` that's already used.
       
   707 			if ( i && _.keys( i._relations ).length ) {
       
   708 				var existing = _.find( i._relations, function( rel ) {
       
   709 					return rel.key === k;
       
   710 				}, this );
       
   711 
       
   712 				if ( existing ) {
       
   713 					warn && console.warn( 'Cannot create relation=%o on %o for model=%o: already taken by relation=%o.',
       
   714 						this, k, i, existing );
       
   715 					return false;
       
   716 				}
       
   717 			}
       
   718 
       
   719 			return true;
       
   720 		},
       
   721 
       
   722 		/**
       
   723 		 * Set the related model(s) for this relation
       
   724 		 * @param {Backbone.Model|Backbone.Collection} related
       
   725 		 */
       
   726 		setRelated: function( related ) {
       
   727 			this.related = related;
       
   728 			this.instance.attributes[ this.key ] = related;
       
   729 		},
       
   730 
       
   731 		/**
       
   732 		 * Determine if a relation (on a different RelationalModel) is the reverse
       
   733 		 * relation of the current one.
       
   734 		 * @param {Backbone.Relation} relation
       
   735 		 * @return {Boolean}
       
   736 		 */
       
   737 		_isReverseRelation: function( relation ) {
       
   738 			return relation.instance instanceof this.relatedModel && this.reverseRelation.key === relation.key &&
       
   739 				this.key === relation.reverseRelation.key;
       
   740 		},
       
   741 
       
   742 		/**
       
   743 		 * Get the reverse relations (pointing back to 'this.key' on 'this.instance') for the currently related model(s).
       
   744 		 * @param {Backbone.RelationalModel} [model] Get the reverse relations for a specific model.
       
   745 		 *    If not specified, 'this.related' is used.
       
   746 		 * @return {Backbone.Relation[]}
       
   747 		 */
       
   748 		getReverseRelations: function( model ) {
       
   749 			var reverseRelations = [];
       
   750 			// Iterate over 'model', 'this.related.models' (if this.related is a Backbone.Collection), or wrap 'this.related' in an array.
       
   751 			var models = !_.isUndefined( model ) ? [ model ] : this.related && ( this.related.models || [ this.related ] ),
       
   752 				relations = null,
       
   753 				relation = null;
       
   754 
       
   755 			for( var i = 0; i < ( models || [] ).length; i++ ) {
       
   756 				relations = models[ i ].getRelations() || [];
       
   757 
       
   758 				for( var j = 0; j < relations.length; j++ ) {
       
   759 					relation = relations[ j ];
       
   760 
       
   761 					if ( this._isReverseRelation( relation ) ) {
       
   762 						reverseRelations.push( relation );
       
   763 					}
       
   764 				}
       
   765 			}
       
   766 
       
   767 			return reverseRelations;
       
   768 		},
       
   769 
       
   770 		/**
       
   771 		 * When `this.instance` is destroyed, cleanup our relations.
       
   772 		 * Get reverse relation, call removeRelated on each.
       
   773 		 */
       
   774 		destroy: function() {
       
   775 			this.stopListening();
       
   776 
       
   777 			if ( this instanceof Backbone.HasOne ) {
       
   778 				this.setRelated( null );
       
   779 			}
       
   780 			else if ( this instanceof Backbone.HasMany ) {
       
   781 				this.setRelated( this._prepareCollection() );
       
   782 			}
       
   783 
       
   784 			_.each( this.getReverseRelations(), function( relation ) {
       
   785 				relation.removeRelated( this.instance );
       
   786 			}, this );
       
   787 		}
       
   788 	});
       
   789 
       
   790 	Backbone.HasOne = Backbone.Relation.extend({
       
   791 		options: {
       
   792 			reverseRelation: { type: 'HasMany' }
       
   793 		},
       
   794 
       
   795 		initialize: function( opts ) {
       
   796 			this.listenTo( this.instance, 'relational:change:' + this.key, this.onChange );
       
   797 
       
   798 			var related = this.findRelated( opts );
       
   799 			this.setRelated( related );
       
   800 
       
   801 			// Notify new 'related' object of the new relation.
       
   802 			_.each( this.getReverseRelations(), function( relation ) {
       
   803 				relation.addRelated( this.instance, opts );
       
   804 			}, this );
       
   805 		},
       
   806 
       
   807 		/**
       
   808 		 * Find related Models.
       
   809 		 * @param {Object} [options]
       
   810 		 * @return {Backbone.Model}
       
   811 		 */
       
   812 		findRelated: function( options ) {
       
   813 			var related = null;
       
   814 
       
   815 			options = _.defaults( { parse: this.options.parse }, options );
       
   816 
       
   817 			if ( this.keyContents instanceof this.relatedModel ) {
       
   818 				related = this.keyContents;
       
   819 			}
       
   820 			else if ( this.keyContents || this.keyContents === 0 ) { // since 0 can be a valid `id` as well
       
   821 				var opts = _.defaults( { create: this.options.createModels }, options );
       
   822 				related = this.relatedModel.findOrCreate( this.keyContents, opts );
       
   823 			}
       
   824 
       
   825 			// Nullify `keyId` if we have a related model; in case it was already part of the relation
       
   826 			if ( related ) {
       
   827 				this.keyId = null;
       
   828 			}
       
   829 
       
   830 			return related;
       
   831 		},
       
   832 
       
   833 		/**
       
   834 		 * Normalize and reduce `keyContents` to an `id`, for easier comparison
       
   835 		 * @param {String|Number|Backbone.Model} keyContents
       
   836 		 */
       
   837 		setKeyContents: function( keyContents ) {
       
   838 			this.keyContents = keyContents;
       
   839 			this.keyId = Backbone.Relational.store.resolveIdForItem( this.relatedModel, this.keyContents );
       
   840 		},
       
   841 
       
   842 		/**
       
   843 		 * Event handler for `change:<key>`.
       
   844 		 * If the key is changed, notify old & new reverse relations and initialize the new relation.
       
   845 		 */
       
   846 		onChange: function( model, attr, options ) {
       
   847 			// Don't accept recursive calls to onChange (like onChange->findRelated->findOrCreate->initializeRelations->addRelated->onChange)
       
   848 			if ( this.isLocked() ) {
       
   849 				return;
       
   850 			}
       
   851 			this.acquire();
       
   852 			options = options ? _.clone( options ) : {};
       
   853 
       
   854 			// 'options.__related' is set by 'addRelated'/'removeRelated'. If it is set, the change
       
   855 			// is the result of a call from a relation. If it's not, the change is the result of
       
   856 			// a 'set' call on this.instance.
       
   857 			var changed = _.isUndefined( options.__related ),
       
   858 				oldRelated = changed ? this.related : options.__related;
       
   859 
       
   860 			if ( changed ) {
       
   861 				this.setKeyContents( attr );
       
   862 				var related = this.findRelated( options );
       
   863 				this.setRelated( related );
       
   864 			}
       
   865 
       
   866 			// Notify old 'related' object of the terminated relation
       
   867 			if ( oldRelated && this.related !== oldRelated ) {
       
   868 				_.each( this.getReverseRelations( oldRelated ), function( relation ) {
       
   869 					relation.removeRelated( this.instance, null, options );
       
   870 				}, this );
       
   871 			}
       
   872 
       
   873 			// Notify new 'related' object of the new relation. Note we do re-apply even if this.related is oldRelated;
       
   874 			// that can be necessary for bi-directional relations if 'this.instance' was created after 'this.related'.
       
   875 			// In that case, 'this.instance' will already know 'this.related', but the reverse might not exist yet.
       
   876 			_.each( this.getReverseRelations(), function( relation ) {
       
   877 				relation.addRelated( this.instance, options );
       
   878 			}, this );
       
   879 
       
   880 			// Fire the 'change:<key>' event if 'related' was updated
       
   881 			if ( !options.silent && this.related !== oldRelated ) {
       
   882 				var dit = this;
       
   883 				this.changed = true;
       
   884 				Backbone.Relational.eventQueue.add( function() {
       
   885 					dit.instance.trigger( 'change:' + dit.key, dit.instance, dit.related, options, true );
       
   886 					dit.changed = false;
       
   887 				});
       
   888 			}
       
   889 			this.release();
       
   890 		},
       
   891 
       
   892 		/**
       
   893 		 * If a new 'this.relatedModel' appears in the 'store', try to match it to the last set 'keyContents'
       
   894 		 */
       
   895 		tryAddRelated: function( model, coll, options ) {
       
   896 			if ( ( this.keyId || this.keyId === 0 ) && model.id === this.keyId ) { // since 0 can be a valid `id` as well
       
   897 				this.addRelated( model, options );
       
   898 				this.keyId = null;
       
   899 			}
       
   900 		},
       
   901 
       
   902 		addRelated: function( model, options ) {
       
   903 			// Allow 'model' to set up its relations before proceeding.
       
   904 			// (which can result in a call to 'addRelated' from a relation of 'model')
       
   905 			var dit = this;
       
   906 			model.queue( function() {
       
   907 				if ( model !== dit.related ) {
       
   908 					var oldRelated = dit.related || null;
       
   909 					dit.setRelated( model );
       
   910 					dit.onChange( dit.instance, model, _.defaults( { __related: oldRelated }, options ) );
       
   911 				}
       
   912 			});
       
   913 		},
       
   914 
       
   915 		removeRelated: function( model, coll, options ) {
       
   916 			if ( !this.related ) {
       
   917 				return;
       
   918 			}
       
   919 
       
   920 			if ( model === this.related ) {
       
   921 				var oldRelated = this.related || null;
       
   922 				this.setRelated( null );
       
   923 				this.onChange( this.instance, model, _.defaults( { __related: oldRelated }, options ) );
       
   924 			}
       
   925 		}
       
   926 	});
       
   927 
       
   928 	Backbone.HasMany = Backbone.Relation.extend({
       
   929 		collectionType: null,
       
   930 
       
   931 		options: {
       
   932 			reverseRelation: { type: 'HasOne' },
       
   933 			collectionType: Backbone.Collection,
       
   934 			collectionKey: true,
       
   935 			collectionOptions: {}
       
   936 		},
       
   937 
       
   938 		initialize: function( opts ) {
       
   939 			this.listenTo( this.instance, 'relational:change:' + this.key, this.onChange );
       
   940 
       
   941 			// Handle a custom 'collectionType'
       
   942 			this.collectionType = this.options.collectionType;
       
   943 			if ( _.isFunction( this.collectionType ) && this.collectionType !== Backbone.Collection && !( this.collectionType.prototype instanceof Backbone.Collection ) ) {
       
   944 				this.collectionType = _.result( this, 'collectionType' );
       
   945 			}
       
   946 			if ( _.isString( this.collectionType ) ) {
       
   947 				this.collectionType = Backbone.Relational.store.getObjectByName( this.collectionType );
       
   948 			}
       
   949 			if ( this.collectionType !== Backbone.Collection && !( this.collectionType.prototype instanceof Backbone.Collection ) ) {
       
   950 				throw new Error( '`collectionType` must inherit from Backbone.Collection' );
       
   951 			}
       
   952 
       
   953 			var related = this.findRelated( opts );
       
   954 			this.setRelated( related );
       
   955 		},
       
   956 
       
   957 		/**
       
   958 		 * Bind events and setup collectionKeys for a collection that is to be used as the backing store for a HasMany.
       
   959 		 * If no 'collection' is supplied, a new collection will be created of the specified 'collectionType' option.
       
   960 		 * @param {Backbone.Collection} [collection]
       
   961 		 * @return {Backbone.Collection}
       
   962 		 */
       
   963 		_prepareCollection: function( collection ) {
       
   964 			if ( this.related ) {
       
   965 				this.stopListening( this.related );
       
   966 			}
       
   967 
       
   968 			if ( !collection || !( collection instanceof Backbone.Collection ) ) {
       
   969 				var options = _.isFunction( this.options.collectionOptions ) ?
       
   970 					this.options.collectionOptions( this.instance ) : this.options.collectionOptions;
       
   971 
       
   972 				collection = new this.collectionType( null, options );
       
   973 			}
       
   974 
       
   975 			collection.model = this.relatedModel;
       
   976 
       
   977 			if ( this.options.collectionKey ) {
       
   978 				var key = this.options.collectionKey === true ? this.options.reverseRelation.key : this.options.collectionKey;
       
   979 
       
   980 				if ( collection[ key ] && collection[ key ] !== this.instance ) {
       
   981 					if ( Backbone.Relational.showWarnings && typeof console !== 'undefined' ) {
       
   982 						console.warn( 'Relation=%o; collectionKey=%s already exists on collection=%o', this, key, this.options.collectionKey );
       
   983 					}
       
   984 				}
       
   985 				else if ( key ) {
       
   986 					collection[ key ] = this.instance;
       
   987 				}
       
   988 			}
       
   989 
       
   990 			this.listenTo( collection, 'relational:add', this.handleAddition )
       
   991 				.listenTo( collection, 'relational:remove', this.handleRemoval )
       
   992 				.listenTo( collection, 'relational:reset', this.handleReset );
       
   993 
       
   994 			return collection;
       
   995 		},
       
   996 
       
   997 		/**
       
   998 		 * Find related Models.
       
   999 		 * @param {Object} [options]
       
  1000 		 * @return {Backbone.Collection}
       
  1001 		 */
       
  1002 		findRelated: function( options ) {
       
  1003 			var related = null;
       
  1004 
       
  1005 			options = _.defaults( { parse: this.options.parse }, options );
       
  1006 
       
  1007 			// Replace 'this.related' by 'this.keyContents' if it is a Backbone.Collection
       
  1008 			if ( this.keyContents instanceof Backbone.Collection ) {
       
  1009 				this._prepareCollection( this.keyContents );
       
  1010 				related = this.keyContents;
       
  1011 			}
       
  1012 			// Otherwise, 'this.keyContents' should be an array of related object ids.
       
  1013 			// Re-use the current 'this.related' if it is a Backbone.Collection; otherwise, create a new collection.
       
  1014 			else {
       
  1015 				var toAdd = [];
       
  1016 
       
  1017 				_.each( this.keyContents, function( attributes ) {
       
  1018 					var model = null;
       
  1019 
       
  1020 					if ( attributes instanceof this.relatedModel ) {
       
  1021 						model = attributes;
       
  1022 					}
       
  1023 					else {
       
  1024 						// If `merge` is true, update models here, instead of during update.
       
  1025 						model = this.relatedModel.findOrCreate( attributes,
       
  1026 							_.extend( { merge: true }, options, { create: this.options.createModels } )
       
  1027 						);
       
  1028 					}
       
  1029 
       
  1030 					model && toAdd.push( model );
       
  1031 				}, this );
       
  1032 
       
  1033 				if ( this.related instanceof Backbone.Collection ) {
       
  1034 					related = this.related;
       
  1035 				}
       
  1036 				else {
       
  1037 					related = this._prepareCollection();
       
  1038 				}
       
  1039 
       
  1040 				// By now, both `merge` and `parse` will already have been executed for models if they were specified.
       
  1041 				// Disable them to prevent additional calls.
       
  1042 				related.set( toAdd, _.defaults( { merge: false, parse: false }, options ) );
       
  1043 			}
       
  1044 
       
  1045 			// Remove entries from `keyIds` that were already part of the relation (and are thus 'unchanged')
       
  1046 			this.keyIds = _.difference( this.keyIds, _.pluck( related.models, 'id' ) );
       
  1047 
       
  1048 			return related;
       
  1049 		},
       
  1050 
       
  1051 		/**
       
  1052 		 * Normalize and reduce `keyContents` to a list of `ids`, for easier comparison
       
  1053 		 * @param {String|Number|String[]|Number[]|Backbone.Collection} keyContents
       
  1054 		 */
       
  1055 		setKeyContents: function( keyContents ) {
       
  1056 			this.keyContents = keyContents instanceof Backbone.Collection ? keyContents : null;
       
  1057 			this.keyIds = [];
       
  1058 
       
  1059 			if ( !this.keyContents && ( keyContents || keyContents === 0 ) ) { // since 0 can be a valid `id` as well
       
  1060 				// Handle cases the an API/user supplies just an Object/id instead of an Array
       
  1061 				this.keyContents = _.isArray( keyContents ) ? keyContents : [ keyContents ];
       
  1062 
       
  1063 				_.each( this.keyContents, function( item ) {
       
  1064 					var itemId = Backbone.Relational.store.resolveIdForItem( this.relatedModel, item );
       
  1065 					if ( itemId || itemId === 0 ) {
       
  1066 						this.keyIds.push( itemId );
       
  1067 					}
       
  1068 				}, this );
       
  1069 			}
       
  1070 		},
       
  1071 
       
  1072 		/**
       
  1073 		 * Event handler for `change:<key>`.
       
  1074 		 * If the contents of the key are changed, notify old & new reverse relations and initialize the new relation.
       
  1075 		 */
       
  1076 		onChange: function( model, attr, options ) {
       
  1077 			options = options ? _.clone( options ) : {};
       
  1078 			this.setKeyContents( attr );
       
  1079 			this.changed = false;
       
  1080 
       
  1081 			var related = this.findRelated( options );
       
  1082 			this.setRelated( related );
       
  1083 
       
  1084 			if ( !options.silent ) {
       
  1085 				var dit = this;
       
  1086 				Backbone.Relational.eventQueue.add( function() {
       
  1087 					// The `changed` flag can be set in `handleAddition` or `handleRemoval`
       
  1088 					if ( dit.changed ) {
       
  1089 						dit.instance.trigger( 'change:' + dit.key, dit.instance, dit.related, options, true );
       
  1090 						dit.changed = false;
       
  1091 					}
       
  1092 				});
       
  1093 			}
       
  1094 		},
       
  1095 
       
  1096 		/**
       
  1097 		 * When a model is added to a 'HasMany', trigger 'add' on 'this.instance' and notify reverse relations.
       
  1098 		 * (should be 'HasOne', must set 'this.instance' as their related).
       
  1099 		 */
       
  1100 		handleAddition: function( model, coll, options ) {
       
  1101 			//console.debug('handleAddition called; args=%o', arguments);
       
  1102 			options = options ? _.clone( options ) : {};
       
  1103 			this.changed = true;
       
  1104 
       
  1105 			_.each( this.getReverseRelations( model ), function( relation ) {
       
  1106 				relation.addRelated( this.instance, options );
       
  1107 			}, this );
       
  1108 
       
  1109 			// Only trigger 'add' once the newly added model is initialized (so, has its relations set up)
       
  1110 			var dit = this;
       
  1111 			!options.silent && Backbone.Relational.eventQueue.add( function() {
       
  1112 				dit.instance.trigger( 'add:' + dit.key, model, dit.related, options );
       
  1113 			});
       
  1114 		},
       
  1115 
       
  1116 		/**
       
  1117 		 * When a model is removed from a 'HasMany', trigger 'remove' on 'this.instance' and notify reverse relations.
       
  1118 		 * (should be 'HasOne', which should be nullified)
       
  1119 		 */
       
  1120 		handleRemoval: function( model, coll, options ) {
       
  1121 			//console.debug('handleRemoval called; args=%o', arguments);
       
  1122 			options = options ? _.clone( options ) : {};
       
  1123 			this.changed = true;
       
  1124 
       
  1125 			_.each( this.getReverseRelations( model ), function( relation ) {
       
  1126 				relation.removeRelated( this.instance, null, options );
       
  1127 			}, this );
       
  1128 
       
  1129 			var dit = this;
       
  1130 			!options.silent && Backbone.Relational.eventQueue.add( function() {
       
  1131 				dit.instance.trigger( 'remove:' + dit.key, model, dit.related, options );
       
  1132 			});
       
  1133 		},
       
  1134 
       
  1135 		handleReset: function( coll, options ) {
       
  1136 			var dit = this;
       
  1137 			options = options ? _.clone( options ) : {};
       
  1138 			!options.silent && Backbone.Relational.eventQueue.add( function() {
       
  1139 				dit.instance.trigger( 'reset:' + dit.key, dit.related, options );
       
  1140 			});
       
  1141 		},
       
  1142 
       
  1143 		tryAddRelated: function( model, coll, options ) {
       
  1144 			var item = _.contains( this.keyIds, model.id );
       
  1145 
       
  1146 			if ( item ) {
       
  1147 				this.addRelated( model, options );
       
  1148 				this.keyIds = _.without( this.keyIds, model.id );
       
  1149 			}
       
  1150 		},
       
  1151 
       
  1152 		addRelated: function( model, options ) {
       
  1153 			// Allow 'model' to set up its relations before proceeding.
       
  1154 			// (which can result in a call to 'addRelated' from a relation of 'model')
       
  1155 			var dit = this;
       
  1156 			model.queue( function() {
       
  1157 				if ( dit.related && !dit.related.get( model ) ) {
       
  1158 					dit.related.add( model, _.defaults( { parse: false }, options ) );
       
  1159 				}
       
  1160 			});
       
  1161 		},
       
  1162 
       
  1163 		removeRelated: function( model, coll, options ) {
       
  1164 			if ( this.related.get( model ) ) {
       
  1165 				this.related.remove( model, options );
       
  1166 			}
       
  1167 		}
       
  1168 	});
       
  1169 
       
  1170 	/**
       
  1171 	 * A type of Backbone.Model that also maintains relations to other models and collections.
       
  1172 	 * New events when compared to the original:
       
  1173 	 *  - 'add:<key>' (model, related collection, options)
       
  1174 	 *  - 'remove:<key>' (model, related collection, options)
       
  1175 	 *  - 'change:<key>' (model, related model or collection, options)
       
  1176 	 */
       
  1177 	Backbone.RelationalModel = Backbone.Model.extend({
       
  1178 		relations: null, // Relation descriptions on the prototype
       
  1179 		_relations: null, // Relation instances
       
  1180 		_isInitialized: false,
       
  1181 		_deferProcessing: false,
       
  1182 		_queue: null,
       
  1183 		_attributeChangeFired: false, // Keeps track of `change` event firing under some conditions (like nested `set`s)
       
  1184 
       
  1185 		subModelTypeAttribute: 'type',
       
  1186 		subModelTypes: null,
       
  1187 
       
  1188 		constructor: function( attributes, options ) {
       
  1189 			// Nasty hack, for cases like 'model.get( <HasMany key> ).add( item )'.
       
  1190 			// Defer 'processQueue', so that when 'Relation.createModels' is used we trigger 'HasMany'
       
  1191 			// collection events only after the model is really fully set up.
       
  1192 			// Example: event for "p.on( 'add:jobs' )" -> "p.get('jobs').add( { company: c.id, person: p.id } )".
       
  1193 			if ( options && options.collection ) {
       
  1194 				var dit = this,
       
  1195 					collection = this.collection = options.collection;
       
  1196 
       
  1197 				// Prevent `collection` from cascading down to nested models; they shouldn't go into this `if` clause.
       
  1198 				delete options.collection;
       
  1199 
       
  1200 				this._deferProcessing = true;
       
  1201 
       
  1202 				var processQueue = function( model ) {
       
  1203 					if ( model === dit ) {
       
  1204 						dit._deferProcessing = false;
       
  1205 						dit.processQueue();
       
  1206 						collection.off( 'relational:add', processQueue );
       
  1207 					}
       
  1208 				};
       
  1209 				collection.on( 'relational:add', processQueue );
       
  1210 
       
  1211 				// So we do process the queue eventually, regardless of whether this model actually gets added to 'options.collection'.
       
  1212 				_.defer( function() {
       
  1213 					processQueue( dit );
       
  1214 				});
       
  1215 			}
       
  1216 
       
  1217 			Backbone.Relational.store.processOrphanRelations();
       
  1218 			Backbone.Relational.store.listenTo( this, 'relational:unregister', Backbone.Relational.store.unregister );
       
  1219 
       
  1220 			this._queue = new Backbone.BlockingQueue();
       
  1221 			this._queue.block();
       
  1222 			Backbone.Relational.eventQueue.block();
       
  1223 
       
  1224 			try {
       
  1225 				Backbone.Model.apply( this, arguments );
       
  1226 			}
       
  1227 			finally {
       
  1228 				// Try to run the global queue holding external events
       
  1229 				Backbone.Relational.eventQueue.unblock();
       
  1230 			}
       
  1231 		},
       
  1232 
       
  1233 		/**
       
  1234 		 * Override 'trigger' to queue 'change' and 'change:*' events
       
  1235 		 */
       
  1236 		trigger: function( eventName ) {
       
  1237 			if ( eventName.length > 5 && eventName.indexOf( 'change' ) === 0 ) {
       
  1238 				var dit = this,
       
  1239 					args = arguments;
       
  1240 
       
  1241 				if ( !Backbone.Relational.eventQueue.isLocked() ) {
       
  1242 					// If we're not in a more complicated nested scenario, fire the change event right away
       
  1243 					Backbone.Model.prototype.trigger.apply( dit, args );
       
  1244 				}
       
  1245 				else {
       
  1246 					Backbone.Relational.eventQueue.add( function() {
       
  1247 						// Determine if the `change` event is still valid, now that all relations are populated
       
  1248 						var changed = true;
       
  1249 						if ( eventName === 'change' ) {
       
  1250 							// `hasChanged` may have gotten reset by nested calls to `set`.
       
  1251 							changed = dit.hasChanged() || dit._attributeChangeFired;
       
  1252 							dit._attributeChangeFired = false;
       
  1253 						}
       
  1254 						else {
       
  1255 							var attr = eventName.slice( 7 ),
       
  1256 								rel = dit.getRelation( attr );
       
  1257 
       
  1258 							if ( rel ) {
       
  1259 								// If `attr` is a relation, `change:attr` get triggered from `Relation.onChange`.
       
  1260 								// These take precedence over `change:attr` events triggered by `Model.set`.
       
  1261 								// The relation sets a fourth attribute to `true`. If this attribute is present,
       
  1262 								// continue triggering this event; otherwise, it's from `Model.set` and should be stopped.
       
  1263 								changed = ( args[ 4 ] === true );
       
  1264 
       
  1265 								// If this event was triggered by a relation, set the right value in `this.changed`
       
  1266 								// (a Collection or Model instead of raw data).
       
  1267 								if ( changed ) {
       
  1268 									dit.changed[ attr ] = args[ 2 ];
       
  1269 								}
       
  1270 								// Otherwise, this event is from `Model.set`. If the relation doesn't report a change,
       
  1271 								// remove attr from `dit.changed` so `hasChanged` doesn't take it into account.
       
  1272 								else if ( !rel.changed ) {
       
  1273 									delete dit.changed[ attr ];
       
  1274 								}
       
  1275 							}
       
  1276 							else if ( changed ) {
       
  1277 								dit._attributeChangeFired = true;
       
  1278 							}
       
  1279 						}
       
  1280 
       
  1281 						changed && Backbone.Model.prototype.trigger.apply( dit, args );
       
  1282 					});
       
  1283 				}
       
  1284 			}
       
  1285 			else if ( eventName === 'destroy' ) {
       
  1286 				Backbone.Model.prototype.trigger.apply( this, arguments );
       
  1287 				Backbone.Relational.store.unregister( this );
       
  1288 			}
       
  1289 			else {
       
  1290 				Backbone.Model.prototype.trigger.apply( this, arguments );
       
  1291 			}
       
  1292 
       
  1293 			return this;
       
  1294 		},
       
  1295 
       
  1296 		/**
       
  1297 		 * Initialize Relations present in this.relations; determine the type (HasOne/HasMany), then creates a new instance.
       
  1298 		 * Invoked in the first call so 'set' (which is made from the Backbone.Model constructor).
       
  1299 		 */
       
  1300 		initializeRelations: function( options ) {
       
  1301 			this.acquire(); // Setting up relations often also involve calls to 'set', and we only want to enter this function once
       
  1302 			this._relations = {};
       
  1303 
       
  1304 			_.each( this.relations || [], function( rel ) {
       
  1305 				Backbone.Relational.store.initializeRelation( this, rel, options );
       
  1306 			}, this );
       
  1307 
       
  1308 			this._isInitialized = true;
       
  1309 			this.release();
       
  1310 			this.processQueue();
       
  1311 		},
       
  1312 
       
  1313 		/**
       
  1314 		 * When new values are set, notify this model's relations (also if options.silent is set).
       
  1315 		 * (called from `set`; Relation.setRelated locks this model before calling 'set' on it to prevent loops)
       
  1316 		 * @param {Object} [changedAttrs]
       
  1317 		 * @param {Object} [options]
       
  1318 		 */
       
  1319 		updateRelations: function( changedAttrs, options ) {
       
  1320 			if ( this._isInitialized && !this.isLocked() ) {
       
  1321 				_.each( this._relations, function( rel ) {
       
  1322 					if ( !changedAttrs || ( rel.keySource in changedAttrs || rel.key in changedAttrs ) ) {
       
  1323 						// Fetch data in `rel.keySource` if data got set in there, or `rel.key` otherwise
       
  1324 						var value = this.attributes[ rel.keySource ] || this.attributes[ rel.key ],
       
  1325 							attr = changedAttrs && ( changedAttrs[ rel.keySource ] || changedAttrs[ rel.key ] );
       
  1326 
       
  1327 						// Update a relation if its value differs from this model's attributes, or it's been explicitly nullified.
       
  1328 						// Which can also happen before the originally intended related model has been found (`val` is null).
       
  1329 						if ( rel.related !== value || ( value === null && attr === null ) ) {
       
  1330 							this.trigger( 'relational:change:' + rel.key, this, value, options || {} );
       
  1331 						}
       
  1332 					}
       
  1333 
       
  1334 					// Explicitly clear 'keySource', to prevent a leaky abstraction if 'keySource' differs from 'key'.
       
  1335 					if ( rel.keySource !== rel.key ) {
       
  1336 						delete this.attributes[ rel.keySource ];
       
  1337 					}
       
  1338 				}, this );
       
  1339 			}
       
  1340 		},
       
  1341 
       
  1342 		/**
       
  1343 		 * Either add to the queue (if we're not initialized yet), or execute right away.
       
  1344 		 */
       
  1345 		queue: function( func ) {
       
  1346 			this._queue.add( func );
       
  1347 		},
       
  1348 
       
  1349 		/**
       
  1350 		 * Process _queue
       
  1351 		 */
       
  1352 		processQueue: function() {
       
  1353 			if ( this._isInitialized && !this._deferProcessing && this._queue.isBlocked() ) {
       
  1354 				this._queue.unblock();
       
  1355 			}
       
  1356 		},
       
  1357 
       
  1358 		/**
       
  1359 		 * Get a specific relation.
       
  1360 		 * @param {string} attr The relation key to look for.
       
  1361 		 * @return {Backbone.Relation} An instance of 'Backbone.Relation', if a relation was found for 'attr', or null.
       
  1362 		 */
       
  1363 		getRelation: function( attr ) {
       
  1364 			return this._relations[ attr ];
       
  1365 		},
       
  1366 
       
  1367 		/**
       
  1368 		 * Get all of the created relations.
       
  1369 		 * @return {Backbone.Relation[]}
       
  1370 		 */
       
  1371 		getRelations: function() {
       
  1372 			return _.values( this._relations );
       
  1373 		},
       
  1374 
       
  1375 
       
  1376 		/**
       
  1377 		 * Get a list of ids that will be fetched on a call to `getAsync`.
       
  1378 		 * @param {string|Backbone.Relation} attr The relation key to fetch models for.
       
  1379 		 * @param [refresh=false] Add ids for models that are already in the relation, refreshing them?
       
  1380 		 * @return {Array} An array of ids that need to be fetched.
       
  1381 		 */
       
  1382 		getIdsToFetch: function( attr, refresh ) {
       
  1383 			var rel = attr instanceof Backbone.Relation ? attr : this.getRelation( attr ),
       
  1384 				ids = rel ? ( rel.keyIds && rel.keyIds.slice( 0 ) ) || ( ( rel.keyId || rel.keyId === 0 ) ? [ rel.keyId ] : [] ) : [];
       
  1385 
       
  1386 			// On `refresh`, add the ids for current models in the relation to `idsToFetch`
       
  1387 			if ( refresh ) {
       
  1388 				var models = rel.related && ( rel.related.models || [ rel.related ] );
       
  1389 				_.each( models, function( model ) {
       
  1390 					if ( model.id || model.id === 0 ) {
       
  1391 						ids.push( model.id );
       
  1392 					}
       
  1393 				});
       
  1394 			}
       
  1395 
       
  1396 			return ids;
       
  1397 		},
       
  1398 
       
  1399 		/**
       
  1400 		 * Get related objects. Returns a single promise, which can either resolve immediately (if the related model[s])
       
  1401 		 * are already present locally, or after fetching the contents of the requested attribute.
       
  1402 		 * @param {string} attr The relation key to fetch models for.
       
  1403 		 * @param {Object} [options] Options for 'Backbone.Model.fetch' and 'Backbone.sync'.
       
  1404 		 * @param {Boolean} [options.refresh=false] Fetch existing models from the server as well (in order to update them).
       
  1405 		 * @return {jQuery.Deferred} A jQuery promise object. When resolved, its `done` callback will be called with
       
  1406 		 *  contents of `attr`.
       
  1407 		 */
       
  1408 		getAsync: function( attr, options ) {
       
  1409 			// Set default `options` for fetch
       
  1410 			options = _.extend( { add: true, remove: false, refresh: false }, options );
       
  1411 
       
  1412 			var dit = this,
       
  1413 				requests = [],
       
  1414 				rel = this.getRelation( attr ),
       
  1415 				idsToFetch = rel && this.getIdsToFetch( rel, options.refresh ),
       
  1416 				coll = rel.related instanceof Backbone.Collection ? rel.related : rel.relatedCollection;
       
  1417 
       
  1418 			if ( idsToFetch && idsToFetch.length ) {
       
  1419 				var models = [],
       
  1420 					createdModels = [],
       
  1421 					setUrl,
       
  1422 					createModels = function() {
       
  1423 						// Find (or create) a model for each one that is to be fetched
       
  1424 						models = _.map( idsToFetch, function( id ) {
       
  1425 							var model = rel.relatedModel.findModel( id );
       
  1426 
       
  1427 							if ( !model ) {
       
  1428 								var attrs = {};
       
  1429 								attrs[ rel.relatedModel.prototype.idAttribute ] = id;
       
  1430 								model = rel.relatedModel.findOrCreate( attrs, options );
       
  1431 								createdModels.push( model );
       
  1432 							}
       
  1433 
       
  1434 							return model;
       
  1435 						}, this );
       
  1436 					};
       
  1437 
       
  1438 				// Try if the 'collection' can provide a url to fetch a set of models in one request.
       
  1439 				// This assumes that when 'Backbone.Collection.url' is a function, it can handle building of set urls.
       
  1440 				// To make sure it can, test if the url we got by supplying a list of models to fetch is different from
       
  1441 				// the one supplied for the default fetch action (without args to 'url').
       
  1442 				if ( coll instanceof Backbone.Collection && _.isFunction( coll.url ) ) {
       
  1443 					var defaultUrl = coll.url();
       
  1444 					setUrl = coll.url( idsToFetch );
       
  1445 
       
  1446 					if ( setUrl === defaultUrl ) {
       
  1447 						createModels();
       
  1448 						setUrl = coll.url( models );
       
  1449 
       
  1450 						if ( setUrl === defaultUrl ) {
       
  1451 							setUrl = null;
       
  1452 						}
       
  1453 					}
       
  1454 				}
       
  1455 
       
  1456 				if ( setUrl ) {
       
  1457 					// Do a single request to fetch all models
       
  1458 					var opts = _.defaults(
       
  1459 						{
       
  1460 							error: function() {
       
  1461 								_.each( createdModels, function( model ) {
       
  1462 									model.trigger( 'destroy', model, model.collection, options );
       
  1463 								});
       
  1464 								
       
  1465 								options.error && options.error.apply( models, arguments );
       
  1466 							},
       
  1467 							url: setUrl
       
  1468 						},
       
  1469 						options
       
  1470 					);
       
  1471 
       
  1472 					requests = [ coll.fetch( opts ) ];
       
  1473 				}
       
  1474 				else {
       
  1475 					// Make a request per model to fetch
       
  1476 					if  ( !models.length ) {
       
  1477 						createModels();
       
  1478 					}
       
  1479 
       
  1480 					requests = _.map( models, function( model ) {
       
  1481 						var opts = _.defaults(
       
  1482 							{
       
  1483 								error: function() {
       
  1484 									if ( _.contains( createdModels, model ) ) {
       
  1485 										model.trigger( 'destroy', model, model.collection, options );
       
  1486 									}
       
  1487 									options.error && options.error.apply( models, arguments );
       
  1488 								}
       
  1489 							},
       
  1490 							options
       
  1491 						);
       
  1492 						return model.fetch( opts );
       
  1493 					}, this );
       
  1494 				}
       
  1495 			}
       
  1496 
       
  1497 			return $.when.apply( null, requests ).then(
       
  1498 				function() {
       
  1499 					return Backbone.Model.prototype.get.call( dit, attr );
       
  1500 				}
       
  1501 			);
       
  1502 		},
       
  1503 
       
  1504 		set: function( key, value, options ) {
       
  1505 			Backbone.Relational.eventQueue.block();
       
  1506 
       
  1507 			// Duplicate backbone's behavior to allow separate key/value parameters, instead of a single 'attributes' object
       
  1508 			var attributes,
       
  1509 				result;
       
  1510 
       
  1511 			if ( _.isObject( key ) || key == null ) {
       
  1512 				attributes = key;
       
  1513 				options = value;
       
  1514 			}
       
  1515 			else {
       
  1516 				attributes = {};
       
  1517 				attributes[ key ] = value;
       
  1518 			}
       
  1519 
       
  1520 			try {
       
  1521 				var id = this.id,
       
  1522 					newId = attributes && this.idAttribute in attributes && attributes[ this.idAttribute ];
       
  1523 
       
  1524 				// Check if we're not setting a duplicate id before actually calling `set`.
       
  1525 				Backbone.Relational.store.checkId( this, newId );
       
  1526 
       
  1527 				result = Backbone.Model.prototype.set.apply( this, arguments );
       
  1528 
       
  1529 				// Ideal place to set up relations, if this is the first time we're here for this model
       
  1530 				if ( !this._isInitialized && !this.isLocked() ) {
       
  1531 					this.constructor.initializeModelHierarchy();
       
  1532 
       
  1533 					// Only register models that have an id. A model will be registered when/if it gets an id later on.
       
  1534 					if ( newId || newId === 0 ) {
       
  1535 						Backbone.Relational.store.register( this );
       
  1536 					}
       
  1537 
       
  1538 					this.initializeRelations( options );
       
  1539 				}
       
  1540 				// The store should know about an `id` update asap
       
  1541 				else if ( newId && newId !== id ) {
       
  1542 					Backbone.Relational.store.update( this );
       
  1543 				}
       
  1544 
       
  1545 				if ( attributes ) {
       
  1546 					this.updateRelations( attributes, options );
       
  1547 				}
       
  1548 			}
       
  1549 			finally {
       
  1550 				// Try to run the global queue holding external events
       
  1551 				Backbone.Relational.eventQueue.unblock();
       
  1552 			}
       
  1553 
       
  1554 			return result;
       
  1555 		},
       
  1556 
       
  1557 		clone: function() {
       
  1558 			var attributes = _.clone( this.attributes );
       
  1559 			if ( !_.isUndefined( attributes[ this.idAttribute ] ) ) {
       
  1560 				attributes[ this.idAttribute ] = null;
       
  1561 			}
       
  1562 
       
  1563 			_.each( this.getRelations(), function( rel ) {
       
  1564 				delete attributes[ rel.key ];
       
  1565 			});
       
  1566 
       
  1567 			return new this.constructor( attributes );
       
  1568 		},
       
  1569 
       
  1570 		/**
       
  1571 		 * Convert relations to JSON, omits them when required
       
  1572 		 */
       
  1573 		toJSON: function( options ) {
       
  1574 			// If this Model has already been fully serialized in this branch once, return to avoid loops
       
  1575 			if ( this.isLocked() ) {
       
  1576 				return this.id;
       
  1577 			}
       
  1578 
       
  1579 			this.acquire();
       
  1580 			var json = Backbone.Model.prototype.toJSON.call( this, options );
       
  1581 
       
  1582 			if ( this.constructor._superModel && !( this.constructor._subModelTypeAttribute in json ) ) {
       
  1583 				json[ this.constructor._subModelTypeAttribute ] = this.constructor._subModelTypeValue;
       
  1584 			}
       
  1585 
       
  1586 			_.each( this._relations, function( rel ) {
       
  1587 				var related = json[ rel.key ],
       
  1588 					includeInJSON = rel.options.includeInJSON,
       
  1589 					value = null;
       
  1590 
       
  1591 				if ( includeInJSON === true ) {
       
  1592 					if ( related && _.isFunction( related.toJSON ) ) {
       
  1593 						value = related.toJSON( options );
       
  1594 					}
       
  1595 				}
       
  1596 				else if ( _.isString( includeInJSON ) ) {
       
  1597 					if ( related instanceof Backbone.Collection ) {
       
  1598 						value = related.pluck( includeInJSON );
       
  1599 					}
       
  1600 					else if ( related instanceof Backbone.Model ) {
       
  1601 						value = related.get( includeInJSON );
       
  1602 					}
       
  1603 
       
  1604 					// Add ids for 'unfound' models if includeInJSON is equal to (only) the relatedModel's `idAttribute`
       
  1605 					if ( includeInJSON === rel.relatedModel.prototype.idAttribute ) {
       
  1606 						if ( rel instanceof Backbone.HasMany ) {
       
  1607 							value = value.concat( rel.keyIds );
       
  1608 						}
       
  1609 						else if ( rel instanceof Backbone.HasOne ) {
       
  1610 							value = value || rel.keyId;
       
  1611 
       
  1612 							if ( !value && !_.isObject( rel.keyContents ) ) {
       
  1613 								value = rel.keyContents || null;
       
  1614 							}
       
  1615 						}
       
  1616 					}
       
  1617 				}
       
  1618 				else if ( _.isArray( includeInJSON ) ) {
       
  1619 					if ( related instanceof Backbone.Collection ) {
       
  1620 						value = [];
       
  1621 						related.each( function( model ) {
       
  1622 							var curJson = {};
       
  1623 							_.each( includeInJSON, function( key ) {
       
  1624 								curJson[ key ] = model.get( key );
       
  1625 							});
       
  1626 							value.push( curJson );
       
  1627 						});
       
  1628 					}
       
  1629 					else if ( related instanceof Backbone.Model ) {
       
  1630 						value = {};
       
  1631 						_.each( includeInJSON, function( key ) {
       
  1632 							value[ key ] = related.get( key );
       
  1633 						});
       
  1634 					}
       
  1635 				}
       
  1636 				else {
       
  1637 					delete json[ rel.key ];
       
  1638 				}
       
  1639 
       
  1640 				// In case of `wait: true`, Backbone will simply push whatever's passed into `save` into attributes.
       
  1641 				// We'll want to get this information into the JSON, even if it doesn't conform to our normal
       
  1642 				// expectations of what's contained in it (no model/collection for a relation, etc).
       
  1643 				if ( value === null && options && options.wait ) {
       
  1644 					value = related;
       
  1645 				}
       
  1646 
       
  1647 				if ( includeInJSON ) {
       
  1648 					json[ rel.keyDestination ] = value;
       
  1649 				}
       
  1650 
       
  1651 				if ( rel.keyDestination !== rel.key ) {
       
  1652 					delete json[ rel.key ];
       
  1653 				}
       
  1654 			});
       
  1655 
       
  1656 			this.release();
       
  1657 			return json;
       
  1658 		}
       
  1659 	},
       
  1660 	{
       
  1661 		/**
       
  1662 		 *
       
  1663 		 * @param superModel
       
  1664 		 * @returns {Backbone.RelationalModel.constructor}
       
  1665 		 */
       
  1666 		setup: function( superModel ) {
       
  1667 			// We don't want to share a relations array with a parent, as this will cause problems with reverse
       
  1668 			// relations. Since `relations` may also be a property or function, only use slice if we have an array.
       
  1669 			this.prototype.relations = ( this.prototype.relations || [] ).slice( 0 );
       
  1670 
       
  1671 			this._subModels = {};
       
  1672 			this._superModel = null;
       
  1673 
       
  1674 			// If this model has 'subModelTypes' itself, remember them in the store
       
  1675 			if ( this.prototype.hasOwnProperty( 'subModelTypes' ) ) {
       
  1676 				Backbone.Relational.store.addSubModels( this.prototype.subModelTypes, this );
       
  1677 			}
       
  1678 			// The 'subModelTypes' property should not be inherited, so reset it.
       
  1679 			else {
       
  1680 				this.prototype.subModelTypes = null;
       
  1681 			}
       
  1682 
       
  1683 			// Initialize all reverseRelations that belong to this new model.
       
  1684 			_.each( this.prototype.relations || [], function( rel ) {
       
  1685 				if ( !rel.model ) {
       
  1686 					rel.model = this;
       
  1687 				}
       
  1688 
       
  1689 				if ( rel.reverseRelation && rel.model === this ) {
       
  1690 					var preInitialize = true;
       
  1691 					if ( _.isString( rel.relatedModel ) ) {
       
  1692 						/**
       
  1693 						 * The related model might not be defined for two reasons
       
  1694 						 *  1. it is related to itself
       
  1695 						 *  2. it never gets defined, e.g. a typo
       
  1696 						 *  3. the model hasn't been defined yet, but will be later
       
  1697 						 * In neither of these cases do we need to pre-initialize reverse relations.
       
  1698 						 * However, for 3. (which is, to us, indistinguishable from 2.), we do need to attempt
       
  1699 						 * setting up this relation again later, in case the related model is defined later.
       
  1700 						 */
       
  1701 						var relatedModel = Backbone.Relational.store.getObjectByName( rel.relatedModel );
       
  1702 						preInitialize = relatedModel && ( relatedModel.prototype instanceof Backbone.RelationalModel );
       
  1703 					}
       
  1704 
       
  1705 					if ( preInitialize ) {
       
  1706 						Backbone.Relational.store.initializeRelation( null, rel );
       
  1707 					}
       
  1708 					else if ( _.isString( rel.relatedModel ) ) {
       
  1709 						Backbone.Relational.store.addOrphanRelation( rel );
       
  1710 					}
       
  1711 				}
       
  1712 			}, this );
       
  1713 
       
  1714 			return this;
       
  1715 		},
       
  1716 
       
  1717 		/**
       
  1718 		 * Create a 'Backbone.Model' instance based on 'attributes'.
       
  1719 		 * @param {Object} attributes
       
  1720 		 * @param {Object} [options]
       
  1721 		 * @return {Backbone.Model}
       
  1722 		 */
       
  1723 		build: function( attributes, options ) {
       
  1724 			// 'build' is a possible entrypoint; it's possible no model hierarchy has been determined yet.
       
  1725 			this.initializeModelHierarchy();
       
  1726 
       
  1727 			// Determine what type of (sub)model should be built if applicable.
       
  1728 			var model = this._findSubModelType( this, attributes ) || this;
       
  1729 
       
  1730 			return new model( attributes, options );
       
  1731 		},
       
  1732 
       
  1733 		/**
       
  1734 		 * Determines what type of (sub)model should be built if applicable.
       
  1735 		 * Looks up the proper subModelType in 'this._subModels', recursing into
       
  1736 		 * types until a match is found.  Returns the applicable 'Backbone.Model'
       
  1737 		 * or null if no match is found.
       
  1738 		 * @param {Backbone.Model} type
       
  1739 		 * @param {Object} attributes
       
  1740 		 * @return {Backbone.Model}
       
  1741 		 */
       
  1742 		_findSubModelType: function( type, attributes ) {
       
  1743 			if ( type._subModels && type.prototype.subModelTypeAttribute in attributes ) {
       
  1744 				var subModelTypeAttribute = attributes[ type.prototype.subModelTypeAttribute ];
       
  1745 				var subModelType = type._subModels[ subModelTypeAttribute ];
       
  1746 				if ( subModelType ) {
       
  1747 					return subModelType;
       
  1748 				}
       
  1749 				else {
       
  1750 					// Recurse into subModelTypes to find a match
       
  1751 					for ( subModelTypeAttribute in type._subModels ) {
       
  1752 						subModelType = this._findSubModelType( type._subModels[ subModelTypeAttribute ], attributes );
       
  1753 						if ( subModelType ) {
       
  1754 							return subModelType;
       
  1755 						}
       
  1756 					}
       
  1757 				}
       
  1758 			}
       
  1759 
       
  1760 			return null;
       
  1761 		},
       
  1762 
       
  1763 		/**
       
  1764 		 *
       
  1765 		 */
       
  1766 		initializeModelHierarchy: function() {
       
  1767 			// Inherit any relations that have been defined in the parent model.
       
  1768 			this.inheritRelations();
       
  1769 
       
  1770 			// If we came here through 'build' for a model that has 'subModelTypes' then try to initialize the ones that
       
  1771 			// haven't been resolved yet.
       
  1772 			if ( this.prototype.subModelTypes ) {
       
  1773 				var resolvedSubModels = _.keys( this._subModels );
       
  1774 				var unresolvedSubModels = _.omit( this.prototype.subModelTypes, resolvedSubModels );
       
  1775 				_.each( unresolvedSubModels, function( subModelTypeName ) {
       
  1776 					var subModelType = Backbone.Relational.store.getObjectByName( subModelTypeName );
       
  1777 					subModelType && subModelType.initializeModelHierarchy();
       
  1778 				});
       
  1779 			}
       
  1780 		},
       
  1781 
       
  1782 		inheritRelations: function() {
       
  1783 			// Bail out if we've been here before.
       
  1784 			if ( !_.isUndefined( this._superModel ) && !_.isNull( this._superModel ) ) {
       
  1785 				return;
       
  1786 			}
       
  1787 			// Try to initialize the _superModel.
       
  1788 			Backbone.Relational.store.setupSuperModel( this );
       
  1789 
       
  1790 			// If a superModel has been found, copy relations from the _superModel if they haven't been inherited automatically
       
  1791 			// (due to a redefinition of 'relations').
       
  1792 			if ( this._superModel ) {
       
  1793 				// The _superModel needs a chance to initialize its own inherited relations before we attempt to inherit relations
       
  1794 				// from the _superModel. You don't want to call 'initializeModelHierarchy' because that could cause sub-models of
       
  1795 				// this class to inherit their relations before this class has had chance to inherit it's relations.
       
  1796 				this._superModel.inheritRelations();
       
  1797 				if ( this._superModel.prototype.relations ) {
       
  1798 					// Find relations that exist on the '_superModel', but not yet on this model.
       
  1799 					var inheritedRelations = _.filter( this._superModel.prototype.relations || [], function( superRel ) {
       
  1800 						return !_.any( this.prototype.relations || [], function( rel ) {
       
  1801 							return superRel.relatedModel === rel.relatedModel && superRel.key === rel.key;
       
  1802 						}, this );
       
  1803 					}, this );
       
  1804 
       
  1805 					this.prototype.relations = inheritedRelations.concat( this.prototype.relations );
       
  1806 				}
       
  1807 			}
       
  1808 			// Otherwise, make sure we don't get here again for this type by making '_superModel' false so we fail the
       
  1809 			// isUndefined/isNull check next time.
       
  1810 			else {
       
  1811 				this._superModel = false;
       
  1812 			}
       
  1813 		},
       
  1814 
       
  1815 		/**
       
  1816 		 * Find an instance of `this` type in 'Backbone.Relational.store'.
       
  1817 		 * A new model is created if no matching model is found, `attributes` is an object, and `options.create` is true.
       
  1818 		 * - If `attributes` is a string or a number, `findOrCreate` will query the `store` and return a model if found.
       
  1819 		 * - If `attributes` is an object and is found in the store, the model will be updated with `attributes` unless `options.merge` is `false`.
       
  1820 		 * @param {Object|String|Number} attributes Either a model's id, or the attributes used to create or update a model.
       
  1821 		 * @param {Object} [options]
       
  1822 		 * @param {Boolean} [options.create=true]
       
  1823 		 * @param {Boolean} [options.merge=true]
       
  1824 		 * @param {Boolean} [options.parse=false]
       
  1825 		 * @return {Backbone.RelationalModel}
       
  1826 		 */
       
  1827 		findOrCreate: function( attributes, options ) {
       
  1828 			options || ( options = {} );
       
  1829 			var parsedAttributes = ( _.isObject( attributes ) && options.parse && this.prototype.parse ) ?
       
  1830 				this.prototype.parse( _.clone( attributes ) ) : attributes;
       
  1831 
       
  1832 			// If specified, use a custom `find` function to match up existing models to the given attributes.
       
  1833 			// Otherwise, try to find an instance of 'this' model type in the store
       
  1834 			var model = this.findModel( parsedAttributes );
       
  1835 
       
  1836 			// If we found an instance, update it with the data in 'item' (unless 'options.merge' is false).
       
  1837 			// If not, create an instance (unless 'options.create' is false).
       
  1838 			if ( _.isObject( attributes ) ) {
       
  1839 				if ( model && options.merge !== false ) {
       
  1840 					// Make sure `options.collection` and `options.url` doesn't cascade to nested models
       
  1841 					delete options.collection;
       
  1842 					delete options.url;
       
  1843 
       
  1844 					model.set( parsedAttributes, options );
       
  1845 				}
       
  1846 				else if ( !model && options.create !== false ) {
       
  1847 					model = this.build( parsedAttributes, _.defaults( { parse: false }, options ) );
       
  1848 				}
       
  1849 			}
       
  1850 
       
  1851 			return model;
       
  1852 		},
       
  1853 
       
  1854 		/**
       
  1855 		 * Find an instance of `this` type in 'Backbone.Relational.store'.
       
  1856 		 * - If `attributes` is a string or a number, `find` will query the `store` and return a model if found.
       
  1857 		 * - If `attributes` is an object and is found in the store, the model will be updated with `attributes` unless `options.merge` is `false`.
       
  1858 		 * @param {Object|String|Number} attributes Either a model's id, or the attributes used to create or update a model.
       
  1859 		 * @param {Object} [options]
       
  1860 		 * @param {Boolean} [options.merge=true]
       
  1861 		 * @param {Boolean} [options.parse=false]
       
  1862 		 * @return {Backbone.RelationalModel}
       
  1863 		 */
       
  1864 		find: function( attributes, options ) {
       
  1865 			options || ( options = {} );
       
  1866 			options.create = false;
       
  1867 			return this.findOrCreate( attributes, options );
       
  1868 		},
       
  1869 
       
  1870 		/**
       
  1871 		 * A hook to override the matching when updating (or creating) a model.
       
  1872 		 * The default implementation is to look up the model by id in the store.
       
  1873 		 * @param {Object} attributes
       
  1874 		 * @returns {Backbone.RelationalModel}
       
  1875 		 */
       
  1876 		findModel: function( attributes ) {
       
  1877 			return Backbone.Relational.store.find( this, attributes );
       
  1878 		}
       
  1879 	});
       
  1880 	_.extend( Backbone.RelationalModel.prototype, Backbone.Semaphore );
       
  1881 
       
  1882 	/**
       
  1883 	 * Override Backbone.Collection._prepareModel, so objects will be built using the correct type
       
  1884 	 * if the collection.model has subModels.
       
  1885 	 * Attempts to find a model for `attrs` in Backbone.store through `findOrCreate`
       
  1886 	 * (which sets the new properties on it if found), or instantiates a new model.
       
  1887 	 */
       
  1888 	Backbone.Collection.prototype.__prepareModel = Backbone.Collection.prototype._prepareModel;
       
  1889 	Backbone.Collection.prototype._prepareModel = function( attrs, options ) {
       
  1890 		var model;
       
  1891 
       
  1892 		if ( attrs instanceof Backbone.Model ) {
       
  1893 			if ( !attrs.collection ) {
       
  1894 				attrs.collection = this;
       
  1895 			}
       
  1896 			model = attrs;
       
  1897 		}
       
  1898 		else {
       
  1899 			options = options ? _.clone( options ) : {};
       
  1900 			options.collection = this;
       
  1901 
       
  1902 			if ( typeof this.model.findOrCreate !== 'undefined' ) {
       
  1903 				model = this.model.findOrCreate( attrs, options );
       
  1904 			}
       
  1905 			else {
       
  1906 				model = new this.model( attrs, options );
       
  1907 			}
       
  1908 
       
  1909 			if ( model && model.validationError ) {
       
  1910 				this.trigger( 'invalid', this, attrs, options );
       
  1911 				model = false;
       
  1912 			}
       
  1913 		}
       
  1914 
       
  1915 		return model;
       
  1916 	};
       
  1917 
       
  1918 
       
  1919 	/**
       
  1920 	 * Override Backbone.Collection.set, so we'll create objects from attributes where required,
       
  1921 	 * and update the existing models. Also, trigger 'relational:add'.
       
  1922 	 */
       
  1923 	var set = Backbone.Collection.prototype.__set = Backbone.Collection.prototype.set;
       
  1924 	Backbone.Collection.prototype.set = function( models, options ) {
       
  1925 		// Short-circuit if this Collection doesn't hold RelationalModels
       
  1926 		if ( !( this.model.prototype instanceof Backbone.RelationalModel ) ) {
       
  1927 			return set.call( this, models, options );
       
  1928 		}
       
  1929 
       
  1930 		if ( options && options.parse ) {
       
  1931 			models = this.parse( models, options );
       
  1932 		}
       
  1933 
       
  1934 		var singular = !_.isArray( models ),
       
  1935 			newModels = [],
       
  1936 			toAdd = [],
       
  1937 			model = null;
       
  1938 
       
  1939 		models = singular ? ( models ? [ models ] : [] ) : _.clone( models );
       
  1940 
       
  1941 		//console.debug( 'calling add on coll=%o; model=%o, options=%o', this, models, options );
       
  1942 		for ( var i = 0; i < models.length; i++ ) {
       
  1943 			model = models[i];
       
  1944 			if ( !( model instanceof Backbone.Model ) ) {
       
  1945 				model = Backbone.Collection.prototype._prepareModel.call( this, model, options );
       
  1946 			}
       
  1947 			if ( model ) {
       
  1948 				toAdd.push( model );
       
  1949 				if ( !( this.get( model ) || this.get( model.cid ) ) ) {
       
  1950 					newModels.push( model );
       
  1951 				}
       
  1952 				// If we arrive in `add` while performing a `set` (after a create, so the model gains an `id`),
       
  1953 				// we may get here before `_onModelEvent` has had the chance to update `_byId`.
       
  1954 				else if ( model.id !== null && model.id !== undefined ) {
       
  1955 					this._byId[ model.id ] = model;
       
  1956 				}
       
  1957 			}
       
  1958 		}
       
  1959 
       
  1960 		// Add 'models' in a single batch, so the original add will only be called once (and thus 'sort', etc).
       
  1961 		// If `parse` was specified, the collection and contained models have been parsed now.
       
  1962 		toAdd = singular ? ( toAdd.length ? toAdd[ 0 ] : null ) : toAdd;
       
  1963 		var result = set.call( this, toAdd, _.defaults( { merge: false, parse: false }, options ) );
       
  1964 
       
  1965 		for ( i = 0; i < newModels.length; i++ ) {
       
  1966 			model = newModels[i];
       
  1967 			// Fire a `relational:add` event for any model in `newModels` that has actually been added to the collection.
       
  1968 			if ( this.get( model ) || this.get( model.cid ) ) {
       
  1969 				this.trigger( 'relational:add', model, this, options );
       
  1970 			}
       
  1971 		}
       
  1972 
       
  1973 		return result;
       
  1974 	};
       
  1975 
       
  1976 	/**
       
  1977 	 * Override 'Backbone.Collection.remove' to trigger 'relational:remove'.
       
  1978 	 */
       
  1979 	var remove = Backbone.Collection.prototype.__remove = Backbone.Collection.prototype.remove;
       
  1980 	Backbone.Collection.prototype.remove = function( models, options ) {
       
  1981 		// Short-circuit if this Collection doesn't hold RelationalModels
       
  1982 		if ( !( this.model.prototype instanceof Backbone.RelationalModel ) ) {
       
  1983 			return remove.call( this, models, options );
       
  1984 		}
       
  1985 
       
  1986 		var singular = !_.isArray( models ),
       
  1987 			toRemove = [];
       
  1988 
       
  1989 		models = singular ? ( models ? [ models ] : [] ) : _.clone( models );
       
  1990 		options || ( options = {} );
       
  1991 
       
  1992 		//console.debug('calling remove on coll=%o; models=%o, options=%o', this, models, options );
       
  1993 		_.each( models, function( model ) {
       
  1994 			model = this.get( model ) || ( model && this.get( model.cid ) );
       
  1995 			model && toRemove.push( model );
       
  1996 		}, this );
       
  1997 
       
  1998 		var result = remove.call( this, singular ? ( toRemove.length ? toRemove[ 0 ] : null ) : toRemove, options );
       
  1999 
       
  2000 		_.each( toRemove, function( model ) {
       
  2001 			this.trigger( 'relational:remove', model, this, options );
       
  2002 		}, this );
       
  2003 
       
  2004 		return result;
       
  2005 	};
       
  2006 
       
  2007 	/**
       
  2008 	 * Override 'Backbone.Collection.reset' to trigger 'relational:reset'.
       
  2009 	 */
       
  2010 	var reset = Backbone.Collection.prototype.__reset = Backbone.Collection.prototype.reset;
       
  2011 	Backbone.Collection.prototype.reset = function( models, options ) {
       
  2012 		options = _.extend( { merge: true }, options );
       
  2013 		var result = reset.call( this, models, options );
       
  2014 
       
  2015 		if ( this.model.prototype instanceof Backbone.RelationalModel ) {
       
  2016 			this.trigger( 'relational:reset', this, options );
       
  2017 		}
       
  2018 
       
  2019 		return result;
       
  2020 	};
       
  2021 
       
  2022 	/**
       
  2023 	 * Override 'Backbone.Collection.sort' to trigger 'relational:reset'.
       
  2024 	 */
       
  2025 	var sort = Backbone.Collection.prototype.__sort = Backbone.Collection.prototype.sort;
       
  2026 	Backbone.Collection.prototype.sort = function( options ) {
       
  2027 		var result = sort.call( this, options );
       
  2028 
       
  2029 		if ( this.model.prototype instanceof Backbone.RelationalModel ) {
       
  2030 			this.trigger( 'relational:reset', this, options );
       
  2031 		}
       
  2032 
       
  2033 		return result;
       
  2034 	};
       
  2035 
       
  2036 	/**
       
  2037 	 * Override 'Backbone.Collection.trigger' so 'add', 'remove' and 'reset' events are queued until relations
       
  2038 	 * are ready.
       
  2039 	 */
       
  2040 	var trigger = Backbone.Collection.prototype.__trigger = Backbone.Collection.prototype.trigger;
       
  2041 	Backbone.Collection.prototype.trigger = function( eventName ) {
       
  2042 		// Short-circuit if this Collection doesn't hold RelationalModels
       
  2043 		if ( !( this.model.prototype instanceof Backbone.RelationalModel ) ) {
       
  2044 			return trigger.apply( this, arguments );
       
  2045 		}
       
  2046 
       
  2047 		if ( eventName === 'add' || eventName === 'remove' || eventName === 'reset' || eventName === 'sort' ) {
       
  2048 			var dit = this,
       
  2049 				args = arguments;
       
  2050 
       
  2051 			if ( _.isObject( args[ 3 ] ) ) {
       
  2052 				args = _.toArray( args );
       
  2053 				// the fourth argument is the option object.
       
  2054 				// we need to clone it, as it could be modified while we wait on the eventQueue to be unblocked
       
  2055 				args[ 3 ] = _.clone( args[ 3 ] );
       
  2056 			}
       
  2057 
       
  2058 			Backbone.Relational.eventQueue.add( function() {
       
  2059 				trigger.apply( dit, args );
       
  2060 			});
       
  2061 		}
       
  2062 		else {
       
  2063 			trigger.apply( this, arguments );
       
  2064 		}
       
  2065 
       
  2066 		return this;
       
  2067 	};
       
  2068 
       
  2069 	// Override .extend() to automatically call .setup()
       
  2070 	Backbone.RelationalModel.extend = function( protoProps, classProps ) {
       
  2071 		var child = Backbone.Model.extend.call( this, protoProps, classProps );
       
  2072 
       
  2073 		child.setup( this );
       
  2074 
       
  2075 		return child;
       
  2076 	};
       
  2077 }));