1: <?php
  2: /**
  3:  * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
  4:  * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
  5:  *
  6:  * Licensed under The MIT License
  7:  * For full copyright and license information, please see the LICENSE.txt
  8:  * Redistributions of files must retain the above copyright notice.
  9:  *
 10:  * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 11:  * @link          http://cakephp.org CakePHP(tm) Project
 12:  * @license       http://www.opensource.org/licenses/mit-license.php MIT License
 13:  */
 14: 
 15: App::uses('View', 'View');
 16: 
 17: /**
 18:  * A view class that is used for JSON responses.
 19:  *
 20:  * By setting the '_serialize' key in your controller, you can specify a view variable
 21:  * that should be serialized to JSON and used as the response for the request.
 22:  * This allows you to omit views + layouts, if your just need to emit a single view
 23:  * variable as the JSON response.
 24:  *
 25:  * In your controller, you could do the following:
 26:  *
 27:  * `$this->set(array('posts' => $posts, '_serialize' => 'posts'));`
 28:  *
 29:  * When the view is rendered, the `$posts` view variable will be serialized
 30:  * into JSON.
 31:  *
 32:  * You can also define `'_serialize'` as an array. This will create a top level object containing
 33:  * all the named view variables:
 34:  *
 35:  * {{{
 36:  * $this->set(compact('posts', 'users', 'stuff'));
 37:  * $this->set('_serialize', array('posts', 'users'));
 38:  * }}}
 39:  *
 40:  * The above would generate a JSON object that looks like:
 41:  *
 42:  * `{"posts": [...], "users": [...]}`
 43:  *
 44:  * If you don't use the `_serialize` key, you will need a view. You can use extended
 45:  * views to provide layout like functionality.
 46:  *
 47:  * @package       Cake.View
 48:  * @since         CakePHP(tm) v 2.1.0
 49:  */
 50: class JsonView extends View {
 51: 
 52: /**
 53:  * JSON views are always located in the 'json' sub directory for a
 54:  * controllers views.
 55:  *
 56:  * @var string
 57:  */
 58:     public $subDir = 'json';
 59: 
 60: /**
 61:  * Constructor
 62:  *
 63:  * @param Controller $controller
 64:  */
 65:     public function __construct(Controller $controller = null) {
 66:         parent::__construct($controller);
 67:         if (isset($controller->response) && $controller->response instanceof CakeResponse) {
 68:             $controller->response->type('json');
 69:         }
 70:     }
 71: 
 72: /**
 73:  * Render a JSON view.
 74:  *
 75:  * Uses the special '_serialize' parameter to convert a set of
 76:  * view variables into a JSON response. Makes generating simple
 77:  * JSON responses very easy. You can omit the '_serialize' parameter,
 78:  * and use a normal view + layout as well.
 79:  *
 80:  * @param string $view The view being rendered.
 81:  * @param string $layout The layout being rendered.
 82:  * @return string The rendered view.
 83:  */
 84:     public function render($view = null, $layout = null) {
 85:         if (isset($this->viewVars['_serialize'])) {
 86:             return $this->_serialize($this->viewVars['_serialize']);
 87:         }
 88:         if ($view !== false && $this->_getViewFileName($view)) {
 89:             return parent::render($view, false);
 90:         }
 91:     }
 92: 
 93: /**
 94:  * Serialize view vars
 95:  *
 96:  * @param array $serialize The viewVars that need to be serialized
 97:  * @return string The serialized data
 98:  */
 99:     protected function _serialize($serialize) {
100:         if (is_array($serialize)) {
101:             $data = array();
102:             foreach ($serialize as $key) {
103:                 $data[$key] = $this->viewVars[$key];
104:             }
105:         } else {
106:             $data = isset($this->viewVars[$serialize]) ? $this->viewVars[$serialize] : null;
107:         }
108:         return json_encode($data);
109:     }
110: 
111: }
112: