如何使用 Laravel API 在 AngularJS 表单中发送 csrf_token()

I am trying to build an angular + laravel rest application. I can get the views of my database. When I try to add new items. I get 500 error telling me mismatch csrf token. My form layout is :

<form class="form-horizontal" ng-submit="addItem()">

  <input type="text" ng-model="itemEntry" placeholder="Type and hit Enter to add item">
</form>

This is how I try to add item to database :

$scope.addItem = function(CSRF_TOKEN) {
    $http.post('/shop', { text: $scope.itemEntry, csrf_token: CSRF_TOKEN} ).success(function(data, status) {
        if(data) {
            var last = _.last($scope.items);
            _token = CSRF_TOKEN;
            $scope.items.push({text: $scope.itemEntry, bought: false, id: (last.id + 1) });
            $scope.itemEntry = '';
            console.log($scope.items);
        } else {
            console.log('There was a problem. Status: ' + status + '; Data: ' + data);
        }
    }).error(function(data, status) {
            console.log('status: ' + status);
        });

}

以下是我在应用程序中使用的过滤:

Route::filter('csrf', function()
{
    if (Session::token() != Input::get('_token'))
    {
        throw new Illuminate\Session\TokenMismatchException;
    }
});

在我的Blade 视图中，我使用了以下功能:

<input type="hidden" name="_token" value="{{ csrf_token() }}" />

How can I send the csrf_token when I use html forms?

Thanks

Edit 1 : Adding header to post request like this does not give errors.

  $http({
    method  : 'POST',
    url     : '/shop',
    data    :  $scope.itemEntry,  // pass in data as strings
    headers : { 'Content-Type': 'application/x-www-form-urlencoded' }   
  });