AngularJS job queue

queue.coffee

angular.module('Queue')

.factory('Queue', ($q) ->
  class Queue
    constructor: ->
      @queue = []
      @processing = no

    enqueue: (func) =>
      defer = $q.defer()

      @queue.push
        func: func
        defer: defer

      @processQueue()

      defer.promise

    processQueue: ->
      return if @processing

      next = @queue.shift()

      if next?
        @processing = yes

        next.func().then((res) =>
          @processing = no

          next.defer.resolve(res)

          @processQueue()
        , (err) =>
          next.defer.reject(err)

          @processQueue()
        )
)

# Usage:

# queue = new Queue()
#
# doSomethingSerial: ->
#   queue.enqueue ->
#     defer = $q.defer()
#
#     defer.resolve()
#
#     defer.promise