Queue to manage ajax requests (made for angularjs $resource objects)

gistfile1.js

/*

Example usage:
ajaxEnqueue(Resource.get, {id: 1}, function(val) {console.log("API returned "+val)"})

Where Resource is an angular $resource object.

This queue will throttle AJAX requests so that only a limited number (ajaxParallel) are in flight at a time.

*/

//TODO: Encapsulate this in a service object, get rid of globals.

var ajaxQueue = [];
var ajaxParallel = 10;
var ajaxOutstanding = 0;

function ajaxEnqueue(method, params, success, failure) {
    ajaxQueue.push(function() {
        method(params, function(val) {
            if (typeof(success) == "function") {
                success(val);
            }
            ajaxOutstanding--;
            ajaxDequeue();
        }, function(val) {
            if (typeof(failure) == "function") {
                failure(val);
            }
            ajaxOutstanding--;
            ajaxDequeue();
        });
    });
    ajaxDequeue();
}

function ajaxDequeue() {
    if (ajaxOutstanding < ajaxParallel && ajaxQueue.length > 0) {
        ajaxOutstanding++;
        ajaxQueue.shift()();
    }
}