CoffeeScript version of jQuery.ajaxQueue

jQuery.ajaxQueue.coffee

# <reference path="jquery-1.8.0.min.js" />
# from: https:#gist.github.com/1039247

###
* jQuery.ajaxQueue - A queue for ajax requests
* 
* (c) 2011 Corey Frang
* Dual licensed under the MIT and GPL licenses.
*
* Requires jQuery 1.5+
###


(($) ->

    # jQuery on an empty object, we are going to use this as our Queue 
    ajaxQueue = $({})

    $.ajaxQueue = (ajaxOpts, stopQueueAfterError) ->
    
        jqXHR = null
        dfd = $.Deferred()
        promise = dfd.promise()

        stopQueueAfterError = stopQueueAfterError || true

        #queue our ajax request
        ajaxQueue.queue( doRequest )

        # add the abort method
        promise.abort = (statusText) ->
            # proxy abort to the jqXHR if it is active 
            if jqXHR
                jqXHR.abort statusText 
        
            # if there wasn't already a jqXHR we need to remove from queue
            queue = ajaxQueue.queue()
            index = $.inArray doRequest, queue 

            if index > -1 
                queue.splice index, 1 
        
            # and then reject the deferred
            dfd.rejectWith ajaxOpts.context || ajaxOpts, [ promise, statusText, "" ]
            promise
    

        # run the actual query
        doRequest = (next) ->
            failCallback = -> 
                next()
                return
        
            if stopQueueAfterError
                failCallback = -> 
                    # cannot continue to process queue after an error 
                    return

            jqXHR = $.ajax(ajaxOpts)
                .done(dfd.resolve)
                .fail(dfd.reject)
                .then(next, failCallback)
    
        promise

)(jQuery)