Creating a Cross-Origin Resource Sharing (CORS) Controller in PencilBlue

cors_controller.js

/*
    Copyright (C) 2015  PencilBlue, LLC

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

module.exports = function(pb) {

    //PB dependencies
    var util           = pb.util;
    var BaseController = pb.BaseController;
    var PluginService  = pb.PluginService;

    /**
     * CORS Controller - A sample controller to demonstrate how open up API endpoints for cross domain requests
     * 
     * @class CorsApiController
     * @constructor
     * @extends BaseController
     */
    function CorsApiController(){}
    util.inherits(CorsApiController, BaseController);

    /**
     * The handler for responding to the options request
     * @method render
     * @param {Function} cb
     */
    CorsApiController.prototype.render = function(cb) {
        var result = {
            content: '',
            headers: {
                'Access-Control-Allow-Origin': "*"
            }
        };
        cb(result);
    };
    
    /**
     * Provides the routes that are to be handled by an instance of this prototype.  
     * The route provides a definition of path, permissions, authentication, and 
     * expected content type. In this particular case we are building a simple 
     * API with no special CRUD operations.  Therefore, we can leverage the 
     * power of the BaseApiController and let it do the heavy lifting for us.  
     * All we have to do is define the routes.
     * Method is optional
     * Path is required
     * Permissions are optional
     * Access levels are optional
     * Content type is optional
     * 
     * @param cb A callback of the form: cb(error, array of objects)
     */
    CorsApiController.getRoutes = function(cb) {
        var routes = [
            {
                //opens up all endpoints
                method: 'options',
                path: "*",
                handler: "render",
                auth_required: false,
            },
            {
                //opens up all endpoints under a the API prefix
                method: 'options',
                path: "/api/*",
                handler: "render",
                auth_required: false,
            },
            {
                //opens up a specific end-point
                method: 'options',
                path: "/api/articles",
                handler: "render",
                auth_required: false,
            },
        ];
        cb(null, routes);
    };

    //exports
    return CorsApiController;
};