AngularJS ngResource does not send native header

Question

I am trying to use ngResource to request a REST API. I need to specify my API key in a custom header. I tried it like this:

angular.module('ApiService', ['ngResource'])

  .factory('Api', ['$resource', function($resource) {

    this.apiEndpoint = '';
    this.apiKey = '';

    return {

      init: function(apiEndpoint, apiKey) {
        this.apiEndpoint = apiEndpoint;
        this.apiKey = apiKey;
      },

      get: function(collection) {
        return $resource(this.apiEndpoint + 'api/1/' + collection, {},
          {
            get: {
              method: 'JSONP',
              headers: {'api_key': this.apiKey},
              params: {callback: 'JSON_CALLBACK'}
            }
          }
        ).get();
      }

    };

  }]);

which I then use in my controller, for example:

app.controller('MyCtrl', function ($scope, Api, ENV) {
  Api.init(ENV.apiEndpoint, ENV.apiKey);
  var widgets = Api.get('widgets');
});

My custom header is not set when I check XHR. Also, why doesn't XHR start until I call empty .get()after the original method $resource:get()?

I also tried directly setting the headers to $httpResource:

  .config(function($httpProvider) {
    $httpProvider.defaults.headers.get  = {'api_key': 'abc123'};
  })

but when checking a network request, this custom header is not set. What am I missing?

Answer 1

, , , JSONP , . . angularjs $http.jsonp.

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