javascript - How can i store Promise instead of Deferred -

i have piece of code, communicate ios native layer dispatching request callback id, , storing deferred in array. when callback comes, can resolve or reject deferred.

my code:

jsgate = (function () {     function jsgate() {}     jsgate._messagecount = 0;     jsgate._callbackdeferreds = {};     jsgate.dispatch = function (plugin, method, args) {         var callbackid, d, message;         callbackid = this._messagecount;         message = {             plugin: plugin,             method: method,             "arguments": args,             callbackid: callbackid         };         send(message)         this._messagecount++;         d = new deferred;         this._callbackdeferreds[callbackid] = d;         return d.promise;     };      jsgate.callback = function (callbackid, issuccess, valueorreason) {         var d;         d = this._callbackdeferreds[callbackid];         if (issuccess) {             d.resolve(valueorreason[0]);         } else {             d.reject(valueorreason[0]);         }         return delete this._callbackdeferreds[callbackid];     };      return jsgate; })(); 

examples of usage:

jsgate.dispatch("readlater", "fetchsomething", []).then(function (value) {     return console.log(value); }); return jsgate.dispatch("readlater", "asyncerror", []).then(function (value) {     return console.log(value); }, function (reason) {     return console.log("failed: " + reason); }); 

what's best practice using a+ promises?

after long research: there's no clean way of doing without strange hacks. main difference between deferred , promise can't manipulate promise result outside. in general - it's approach, in specific case, need functionality, - have stick deferred.