AngularJS removing data from postdata

Question

I'm following the example from mightygio (http://mightygio.com/2013/05/integrating-rails-and-angularjs-part-3-rest-and-angular-resource) and would like to simplify the postData when updating.

Currently I have this

  $scope.update = ->
    Letter.update
      id: $stateParams['id']
    ,
      letter:
        subject: $scope.letter.subject
        body: $scope.letter.body

    # success
    , (response) ->
      $location.path "/letters"

    # failure
    , (response) ->

When I have a large form with lots of data this gets rather long and hard to maintain. It would be nicer if I could just pass the $scope.letter like so:

  $scope.update = ->
    Letter.update
      id: $stateParams['id']
    ,
      letter: $scope.letter

    # success
    , (response) ->
      $location.path "/letters"

    # failure
    , (response) ->

The problem I have is I cannot pass certain attributes to my backend when updating these are created_at, id & updated_at keys.

How could I remove these keys before sending my JSON to the server?

UPDATE

I suppose I could use something like this, but is there a better way?

  $scope.update = ->
    letter = {}
    #  Strip out id, created_at & updated_at
    angular.forEach($scope.letter, (value,key) ->
      if(key!='id' && key!='created_at' && key!='updated_at')
        letter[key]=value
    ,letter)

    Letter.update
      id: $stateParams['id']
    ,
      letter: letter
    # success
    , (response) ->
      $location.path "/letters"

    # failure
    , (response) ->

Answer 1

Highly recommend to use well known and performant utility libraries like Lo-Dash or Underscore. Using either of these you can easily choose to either include a whitelist of keys, or exclude a list of blacklisted keys.

Whitelist example:

_.pick({name: 'moe', age: 50, userid: 'moe1'}, 'name', 'age');
=> {name: 'moe', age: 50}

Blacklist example:

_.omit({name: 'moe', age: 50, userid: 'moe1'}, 'userid');
=> {name: 'moe', age: 50}

PS If you use the well known Restangular library the decision becomes even easier, as it depends on Lodash (or Underscore) already.