upload.php

<?php
    class Photo extends CI_Controller{
      function __construct(){
        parent::__construct();

        header('Access-Control-Allow-Origin: *');
        header('Access-Control-Allow-Method: PUT, GET, POST, DELETE, OPTIONS*');
        header('Access-Control-Allow-Headers: Content-Type, x-xsrf-token');
      }

      function upload() {

        $target_path = "upload/";

        $target_path = $target_path . basename( $_FILES['file']['name']);

        if (move_uploaded_file($_FILES['file']['tmp_name'], $target_path)) {
            echo "Upload and move success";
        } else {
        echo $target_path;
            echo "There was an error uploading the file, please try again!";
        }
      }

    }
 ?>