Adding Promise.fromDeferred helper to wrap jQuery Deferreds

[kevinrobinson]

RSVP is great - thoroughly clear and small enough that it can be used as a fundamental abstraction across all my JS. I'm mostly working browser-side and mostly using $.Deferred now, and was surprised that it didn't chain the way I expected. In surveying the landscape, I didn't find a good fit, mostly for the same reasons you mentioned in http://news.ycombinator.com/item?id=4662222. So thanks!

I'm not sure if this fits with your goals for the project, but I think the idea to add helper functions that can wrap other promise abstractions into RSVP.Promises would be helpful in adopting it in my projects. This pull request adds that helper function for wrapping $.Deferred and is similar to #4 which wraps functions using Node-style callback parameters.

This is a little extra cruft (and basically useless for the Node build), so maybe this works better as an extension that is part of the project but a separate output of the build.

Thanks!

[kevinrobinson]

Example usage:

  var deferred = $.Deferred();
  var rsvpPromise = RSVP.Promise.fromDeferred(deferred);
  rsvpPromise.then(function(args) {
    //in here, args will be equal to [1,2,3]
  });
  deferred.resolve(1,2,3);

[russelldavis]

+1 for this (or something similar from #60). One issue with this particular implementation -- if an exception gets thrown in the success handler for the original jQuery Deferred, this won't reject the deferred, which Promises/A+ requires.

[wagenet]

@kevinrobinson Sorry for the slow activity on this. @wycats, is this something you're interested in?

[stefanpenner]

I believe #63 will provide the functionality you need and it does so by implementing the-promise-resolution-procedure

Let me know if #63 works for you

[stefanpenner]

I believe #63 addresses this.