Source: services/FileReaderService.js

    /**
     * @ngdoc service
     * @name FileReaderService
     * @module s4c.services.FileReaderService
     * 
     * @description  Componente para acesso a api do backend e/ou comunicação entre controllers
     * 
     *
     */
     
(function () {
    angular.module('s4c.services')
        .factory('FileReaderService', FileReaderService);

    FileReaderService.$inject = []

   /**	
	* @method FileReaderService
	*/
    function FileReaderService() {
        var service = {
            readTextFile: readTextFile
        };

  		/**	
		* @method readTextFile
		* @param {*} file
		* @param {*} callback
		*/
        function readTextFile(file, callback) {
            var rawFile = new XMLHttpRequest();
            rawFile.overrideMimeType("application/json");
            rawFile.open("GET", file, true);
            rawFile.onreadystatechange = function () {
                if (rawFile.readyState === 4 && (rawFile.status == "200" || rawFile.status == 0)) {
                    callback(rawFile.responseText);
                }
            }
            rawFile.send(null);
        }
        return service;
    }
}());