[AngularJS + cryptoJS + Gravatar] Provider vs factory

Configurable Bits Need a Provider

We want to be able to configure the characterLength before Tweetableruns. Refactor the Tweetable factory into a provider and expose asetLength() function that will allow us to set a characterLength in our app config.

angular.module('NoteWrangler')
.factory('Tweetable', ['$http', function TweetableFactory($http) {
  var characterLength = 144;

  return function(potentialTweet) {
    return $http({
      method: 'POST',
      url: 'http://gentle-spire-1153.herokuapp.com/tweet',
      data: {
        description: potentialTweet,
        maxLength: characterLength
      }
    });
  };
}]);

Change the factory definition into a provider definition.

.provider('Tweetable', ['$http', function TweetableProvider($http) {

Wrap the existing function returned by our TweetableProvider() function in a call to the $get() function required by providers. Don't forget to move the $http service injection!

angular.module('NoteWrangler')
.provider('Tweetable', [function TweetableProvider() {
  var characterLength = 144;
  this.$get = function($http){
    return function(potentialTweet) {
      return $http({
        method: 'POST',
        url: 'http://gentle-spire-1153.herokuapp.com/tweet',
        data: {
          description: potentialTweet,
          maxLength: characterLength
        }
      });
    };
  };
}]);

Create a setLength() function attached to the provider that sets thecharacterLength variable.

angular.module('NoteWrangler')
.provider('Tweetable', [function TweetableProvider() {
  var characterLength = 144;
  this.$get = function($http){
    return function(potentialTweet) {
      return $http({
        method: 'POST',
        url: 'http://gentle-spire-1153.herokuapp.com/tweet',
        data: {
          description: potentialTweet,
          maxLength: characterLength
        }
      });
    };
  };
  
  this.setLength = function(length){
      characterLength = length;
  };
}]);

Configuring the Tweet Length

Now that our provider is ready to go, let's call the setLength() method ofTweetableProvider to configure the acceptable maximum tweet length. Instead of 144 characters, we need to allow for a characterLength of 40.

Let's call config() on our NoteWrangler module and provide it an anonymous function.

Inject TweetableProvider into the config() function.

Call the setLength() function of TweetableProvider from within the config()function and pass it a value of 40.

angular.module('NoteWrangler', ['ngRoute'])
.config(function(TweetableProvider){
    TweetableProvider.setLength(40);
});

Link: https://code.google.com/p/crypto-js/