Wraps a function in a dojo.Deferred object.

DeferredWrapper.js

define([
    'dojo/_base/declare',
    'dojo/_base/lang',
    'dojo/Deferred'
], function (declare, lang, Deferred) {
    return declare([Deferred], {
        
        // summary:
        //      Wraps a function in a dojo.Deferred object.

        // The result of the callback - can be another Deferred object
        inner: null,

        constructor: function (/*Function*/ callback) {
            // summary:
            //      Creates a Deferred which calls the callback when resolved.
            
            this.then(lang.hitch(this, function() {
                this.inner = callback();
            }));
        }

    });

});