angular_serial_resolver.js.coffee

# Resolves an arbitrary number of promises in order. Returns the last promise
# unresolved (or an empty promise if there were none) for chainability.
serialResolver = (promises) ->
  promise = promises.shift()

  switch
    # Promise array was empty to begin with.
    when promise is undefined
      $q.when()
    # For the last promise in the array, return it for chainability.
    when promises.length is 0
      promise
    # Process a promise serially and call the next one.
    else
      promise.then ->
        serialResolver(promises)