Fix for issue #5 / Parse deserialization of nested objects

Author: typhonrt

src/parseExtend.js

@@ -6,6 +6,8 @@ import _             from 'underscore';
 import extend        from 'backbone-es6/src/extend.js';
 import modelExtend   from './modelExtend.js';
 
+import Utils         from 'typhonjs-core-utils/src/Utils.js';
+
 // Add HTTPS image fetch substitution to Parse.Object ---------------------------------------------------------------
 
 /**
@@ -20,8 +22,7 @@ Parse.Object.prototype.getHTTPSUrl = function(key)
 
    if (!_.isUndefined(urlRequest) && urlRequest !== null && !_.isUndefined(urlRequest.url))
    {
-      return urlRequest.url().replace('http://files.parsetfss.com/',
-       'https://s3.amazonaws.com/files.parsetfss.com/');
+      return urlRequest.url().replace('http://files.parsetfss.com/', 'https://s3.amazonaws.com/files.parsetfss.com/');
    }
 };
 
@@ -56,4 +57,96 @@ export default function parseExtend(Backbone)
           'https://s3.amazonaws.com/files.parsetfss.com/');
       }
    };
-}
+// Various fixes for Backbone / Parse integration -------------------------------------------------------------------
+
+   s_FIX_ISSUE5_DESERIALIZATION(Backbone);
+}
+
+/**
+ * Stores subclass information registered with Parse.Object.
+ * @type {{}}
+ */
+const s_PARSE_OBJECT_CLASS_MAP = {};
+
+/**
+ * Fixes backbone-parse-es6 issue #5 - https://github.com/typhonjs-backbone-parse/backbone-parse-es6/issues/5
+ *
+ * It's necessary to override Parse.Object.fromJSON to support proper deserialization.
+ *
+ * It should be noted that ParseModel now supports a `subClasses` getter which defines an object hash of an associated
+ * className with the constructor / class to associate. By adding this to your ParseModel / Backbone.Model classes
+ * this will automatically register them with `Parse.Object.registerSubclass`.
+ *
+ * For a test suite please see:
+ * https://github.com/typhonjs-demos-test/typhonjs-issues-demos/tree/master/repos/backbone-parse-es6/src/issue5
+ *
+ * @param {object}   Backbone - Backbone instance
+ */
+const s_FIX_ISSUE5_DESERIALIZATION = (Backbone) =>
+{
+   /**
+    * Override `getSubclass` as it is referenced in `fromJSON`.
+    *
+    * @param {string}   className - Parse.Object className / table ID.
+    *
+    * @returns {*}
+    */
+   Parse.Object.getSubclass = (className) =>
+   {
+      if (typeof className !== 'string') { throw new TypeError('The first argument must be a valid class name.'); }
+
+      return s_PARSE_OBJECT_CLASS_MAP[className];
+   };
+
+   /**
+    * Override `registerSubclass` as it needs to use `s_PARSE_OBJECT_CLASS_MAP` above.
+    *
+    * @param {string}   className - Parse.Object className / table ID.
+    * @param {function} constructor - Class / constructor to register as a subclass.
+    */
+   Parse.Object.registerSubclass = (className, constructor) =>
+   {
+      if (typeof className !== 'string') { throw new TypeError('The first argument must be a valid class name.'); }
+
+      if (typeof constructor === 'undefined') { throw new TypeError('You must supply a subclass constructor.'); }
+
+      if (typeof constructor !== 'function')
+      {
+         throw new TypeError(
+          'You must register the subclass constructor. Did you attempt to register an instance of the subclass?');
+      }
+
+      s_PARSE_OBJECT_CLASS_MAP[className] = constructor;
+
+      if (!constructor.className) { constructor.className = className; }
+   };
+
+   /**
+    * Override `fromJSON` to check constructor. If it is a type of `Backbone.Model` then construct it as a `ParseModel`
+    * passing in the associated `Parse.Object` otherwise just return the `Parse.Object`.
+    *
+    * @param {object}   json - JSON object
+    *
+    * @returns {*}
+    */
+   Parse.Object.fromJSON = (json) =>
+   {
+      if (!json.className) { throw new Error('Cannot create an object without a className'); }
+
+      const constructor = Parse.Object.getSubclass(json.className);
+      const parseObject = new Parse.Object(json.className);
+      const otherAttributes = {};
+
+      for (const attr in json)
+      {
+         if (attr !== 'className' && attr !== '__type') { otherAttributes[attr] = json[attr]; }
+      }
+
+      parseObject._finishFetch(otherAttributes);
+
+      if (json.objectId) { parseObject._setExisted(true); }
+
+      return constructor && Utils.isTypeOf(constructor, Backbone.Model) ? new constructor({}, { parseObject }) :
+       parseObject;
+   };
+};