Need jQuery's "when" functionality for mpromise/mongoose

Question

Is there such a thing as a when clause for mpromise/mongoose? I'm looking to do something lke this without having to write my own wrapper for mpromise.

$.when(jQueryPromise1,jQueryPromise3,jQueryPromise3).done(function(r1,r2,r3) {
    // success code
}.fail(function(err1,err2,err3) {
    //failure code
});

I realize chaining exists, that's not what I want. I'm looking for a mechanism in mpromise/mongoose that will execute when all promises have been completed.

Answer 1

Here's a sample implementation of when:

function when(/* promise list */) {
    var promises = [].slice.call(arguments),
        whenPromise = new Promise,
        results = new Array(promises.length),
        remaining = promises.length,
        done = false,
        finish = function() {
            done = true;
        };

    whenPromise.onFulfill(finish).onReject(finish);

    promises.forEach(function(promise) {
        promise.onFulfill(function(result) {
            if (!done) {
                // index of result should correspond to original index of promise
                results[promises.indexOf(promise)] = result;
                if (--remaining == 0) {
                    // fulfill when all are fulfilled
                    whenPromise.fulfill.apply(whenPromise, results);
                }
            }
        }).onReject(function(err) {
            if (!done) {
                // reject when one is rejected (a la jQuery)
                whenPromise.reject(err);
            }
        });
    });
}