Is there a way to create a deferred object wrapper in jQuery

Question

I've been reading a lot about the new jQuery.Deferred object. One thing that'd be really useful would be to be able to convert an existing object into a deferred one, then you'd get 100% flexibility about where you get your data from.

I'm thinking something along the lines of

$.makeDeferred({property: "data"}) // returns an object with .promise() method, in resolved state, and that passes the original object as data/context to any callback function

Does anyone know if this method already exists, or how to go about creating one?

Answer 1

You shouldn't need to wrap your object to get this effect, since most methods that are passed promises as parameters will treat a plain object as an already-resolved promise.

That said, if you really want this, try this:

(function($) {
    $.makeDeferred = function() {
        var d = $.Deferred();
        d.resolve(arguments);
        return d.promise();
    };
))(jQuery);

This would at least allow you to also handle the case where you want to call a method of the promise, eg my_promise.done() , as opposed to passing the promise, ie $.when(my_promise) .

[untested, may not work, E&OE, etc.]

EDIT

Actually, I thnk all you have to do is wrap your plain-old-data in $.when :

$.when({property: "data"})