#56 - Prevent errors when serializing objects with circular references

kiva · May 6, 2014 · 2bcd646 · 2bcd646
1 parent b11f9a1
commit 2bcd646
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Showing 4 changed files with 160 additions and 12 deletions.
diff --git a/src/backbone.siren.js b/src/backbone.siren.js
@@ -500,6 +500,26 @@ _.extend(BbSiren, {
 	}
 
 
+	/**
+	 * Wrapper for .toJSON()
+	 *
+	 * @param {*} val
+	 * @param {Object} options
+	 * @returns {*} A serialized version of the given val.
+	 */
+	, serializeData: function (val, options) {
+		options = options || {};
+
+		if (BbSiren.isHydratedObject(val)) {
+			if (_.indexOf(options.renderedEntities, val.url()) < 0 ) {
+				return val.toJSON(options);
+			}
+		} else {
+			return val;
+		}
+	}
+
+
 	/**
 	 * Parses a raw siren model into a Backbone.Siren.Model and maintains its representation in the store.
 	 *
@@ -875,10 +895,15 @@ _.extend(BbSiren, {
         /**
          * http://backbonejs.org/#Model-toJSON
          *
+         * If passed an actionName, .toJSON() will only serialize the properties from the action's field's
+         *
          * @param {Object} options
          * @returns {Object}
          */
         , toJSON: function (options) {
+			options = options || {};
+			options.renderedEntities = options.renderedEntities || [];
+
             var action
             , json = {}
             , self = this;
@@ -887,19 +912,16 @@ _.extend(BbSiren, {
                 action = this.getActionByName(options.actionName);
             }
 
+			options.renderedEntities.push(this.url());
+
 		    if (action) {
                 _.each(action.fields, function (field) {
-                    var val = self.get(field.name);
-
-                    json[field.name] = BbSiren.isHydratedObject(val)
-                        ? val.toJSON({actionName: field.action})
-                        : val;
+	                options.actionName = field.action;
+	                json[field.name] = BbSiren.serializeData(self.get(field.name), options);
                 });
             } else {
                 _.each(this.attributes, function (val, name) {
-                    json[name] = (val instanceof Backbone.Siren.Model) || (val instanceof Backbone.Siren.Collection)
-                        ? val.toJSON(options)
-                        : val;
+	                json[name] = BbSiren.serializeData(val, options);
                 });
             }
 
@@ -1038,7 +1060,10 @@ _.extend(BbSiren, {
 	     * @returns {Object}
 	     */
 	    , toJSON: function (options) {
-		    options  = options || {};
+			options = options || {};
+			options.renderedEntities = options.renderedEntities || [];
+
+			options.renderedEntities.push(this.url());
 
 //			    if (! options.isNestedBatch) { // @todo WIP
 //				    delete options.actionName;

diff --git a/test/spec/backbone.siren.collection.js b/test/spec/backbone.siren.collection.js
@@ -328,7 +328,14 @@ describe('Siren Collection: ', function () {
 
 
         it('returns an empty array if the collection does not have any matching attributes for the given action', function () {
-            var mySirenCollection = new Backbone.Siren.Collection({actions: [{name: 'do-test'}]});
+            var mySirenCollection = new Backbone.Siren.Collection({
+	            actions: [{
+	                name: 'do-test'
+                }]
+	            , links: [
+		            {rel: ['test'], href:'x.io'}
+	            ]
+            });
 
             expect(mySirenCollection.toJSON({actionName: 'do-test'})).toEqual([]);
         });

diff --git a/test/spec/backbone.siren.js b/test/spec/backbone.siren.js
@@ -200,6 +200,33 @@ describe('Backbone.Siren: ', function () {
 	});
 
 
+	describe('.serializeData()', function () {
+		it('returns a serialized version of the model or collection', function () {
+			this.spy(Backbone.Siren.Model.prototype, 'toJSON');
+			this.spy(Backbone.Siren.Collection.prototype, 'toJSON');
+
+			var settingsModel = new Backbone.Siren.Model(rawSettingsModel);
+			Backbone.Siren.serializeData(settingsModel);
+			expect(settingsModel.toJSON).toHaveBeenCalled();
+
+			var collection = new Backbone.Siren.Collection(rawCollection);
+			Backbone.Siren.serializeData(collection);
+			expect(collection.toJSON).toHaveBeenCalled();
+		});
+
+
+		it('returns the value if it\'s not a Model or Collection', function () {
+			expect(Backbone.Siren.serializeData('two')).toBe('two');
+		});
+
+
+		it('returns `undefined` if val\'s already been rendered', function () {
+			var settingsModel = new Backbone.Siren.Model(rawSettingsModel);
+			expect(Backbone.Siren.serializeData(settingsModel, {renderedEntities: [settingsModel.url()]})).not.toBeDefined();
+		});
+	});
+
+
 	describe('.parseCollection()', function () {
 		it('creates a new collection from a raw collection', function () {
 			var collection = Backbone.Siren.parseCollection(rawCurrentCollection);

diff --git a/test/spec/backbone.siren.model.js b/test/spec/backbone.siren.model.js
@@ -24,7 +24,65 @@ describe('Siren Model: ', function () {
 		    , {"rel":["next"],"href": "http://api.x.io/orders/43"}
         ]
     }
-    , sirenModel, store;
+
+	, rawCircularModel = {
+		// Level one
+		name: 'l1'
+		, properties: {
+			level: 'one'
+		}
+		, entities: [
+			// Level two
+			{
+				name: 'l2'
+				, properties: {
+				level: 'two'
+			}
+				, entities: [
+				// Level three - back to "one"
+				{
+					name: 'l3'
+					, properties: {
+					level: 'one'
+				}
+					, entities: [
+					// Level four - back to "two"
+					{
+						name: 'l4'
+						, properties: {
+						level: 'two'
+					}
+						, entities: []
+						, links: [
+						{rel: ['self'], href: 'x.io/two'}
+					]
+					}
+				]
+					, links: [
+					{rel: ['self'], href: 'x.io/one'}
+				]
+				}
+				, {
+					name: 'random'
+					, properties: {
+						random: 'yes'
+					}
+					, entities: []
+					, links: [
+						{rel: ['self'], href: 'x.io/random'}
+					]
+				}
+			]
+				, links: [
+				{rel: ['self'], href: 'x.io/two'}
+			]
+			}
+		]
+		, links: [
+			{rel: ['self'], href: 'x.io/one'}
+		]
+	}
+	, sirenModel, store;
 
 
     beforeEach(function () {
@@ -342,7 +400,13 @@ describe('Siren Model: ', function () {
         it('returns an empty object if the model does not have any matching attributes for the given action', function () {
 	        // @todo should probably throw instead.
 
-            var mySirenModel = new Backbone.Siren.Model({actions: [{name: 'do-test'}]});
+            var mySirenModel = new Backbone.Siren.Model({actions: [{
+	                name: 'do-test'
+                }]
+	            , links: [
+		            {rel: ['test'], href:'x.io'}
+	            ]
+            });
 
             expect(mySirenModel.toJSON({actionName: 'do-test'})).toEqual({});
         });
@@ -354,6 +418,31 @@ describe('Siren Model: ', function () {
 
 	        expect(model.toJSON()).toEqual(props);
         });
+
+
+	    it('will only parse an entity once', function () {
+		    var mySirenModel = new Backbone.Siren.Model(rawCircularModel);
+		    var serializedData = mySirenModel.toJSON();
+
+		    expect(serializedData.l2.random).toBeDefined();
+		    expect(serializedData.l2.l3).not.toBeDefined();
+
+		    // Nest the circular model one level deeper
+		    mySirenModel = new Backbone.Siren.Model({
+			    properties: {
+				    level: 'top'
+			    }
+			    , entities: [rawCircularModel]
+			    , links: [
+				    {rel: ['self'], href: 'x.io/top'}
+			    ]
+		    });
+
+		    serializedData = mySirenModel.toJSON();
+
+		    expect(serializedData.l1.l2.random).toBeDefined();
+		    expect(serializedData.l1.l2.l3).not.toBeDefined();
+	    });
     });