Question

I use the strophe.archive plugin but the done function of the Deferred object seems to be “undefined” after Strophe sends the query. I also added the plugin to the “shim” of require.js:

        var q = $.Deferred();     
        q = connection.archive.listCollections("[e-mail]");
        console.log(q);
        q.done(function(){
            console.log("DONE");
        });

I get the following trace:

Uncaught TypeError: Cannot call method 'done' of undefined test.js:23
Backbone.View.extend.initialize test.js:23
Backbone.View backbone.js:1148
child backbone.js:1393
Backbone.Router.extend.pageTest router.js:92
(anonymous function) backbone.js:900
(anonymous function) backbone.js:1082
_.some._.any underscore.js:193
_.extend.loadUrl backbone.js:1080
_.extend.navigate backbone.js:1125
_.extend.navigate backbone.js:909
Backbone.View.extend.pageTest test1.js:199
jQuery.event.dispatch require-jquery.js:5385
elemData.handle.eventHandle

shim:

  archive: {
      deps: ["jquery", "strophe"],
      exports: "archive"
  },

Answer 1

You invoke a deferred obj and assign it to q, and then you assign the result of listCollections to q. These are two different and completely unrelated assignments. Just because you made q a deferred initially doesn’t mean that the result from listCollections is now somehow deferrable.

    var q = $.Deferred();  // q is a deferred obj
    q = connection.archive.listCollections("[e-mail]"); // q is undefined

listCollections must return a deferred object for you to be able to call done on it.

Looking at the plugin code, it looks like listCollections doesn’t return anything.

Instead, you must pass listCollections a callback function:

    var q = $.Deferred();     
    q = connection.archive.listCollections("[e-mail]", null, function(){
        console.log("DONE");
    });

Alternatively, you can make a wrapper function for listCollections that will return a deferred.

    function deferrableListCollections () {
        var q = $.Deferred();     
        connection.archive.listCollections("[e-mail]", null, function(){
            q.resolve() ;
        });
        return q;
    }

No you can call something similar to your original code:

    q = deferrableListCollections("[e-mail]");
    q.done(function(){
        console.log("DONE");
    });