1: <?php
  2: /**
  3:  * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
  4:  * Copyright 2005-2012, Cake Software Foundation, Inc. (http://cakefoundation.org)
  5:  *
  6:  * Licensed under The MIT License
  7:  * Redistributions of files must retain the above copyright notice.
  8:  *
  9:  * @copyright     Copyright 2005-2012, Cake Software Foundation, Inc. (http://cakefoundation.org)
 10:  * @link          http://cakephp.org CakePHP(tm) Project
 11:  * @license       MIT License (http://www.opensource.org/licenses/mit-license.php)
 12:  */
 13: 
 14: App::uses('View', 'View');
 15: 
 16: /**
 17:  * A view class that is used for JSON responses.
 18:  *
 19:  * By setting the '_serialize' key in your controller, you can specify a view variable
 20:  * that should be serialized to JSON and used as the response for the request.
 21:  * This allows you to omit views + layouts, if your just need to emit a single view
 22:  * variable as the JSON response.
 23:  *
 24:  * In your controller, you could do the following:
 25:  *
 26:  * `$this->set(array('posts' => $posts, '_serialize' => 'posts'));`
 27:  *
 28:  * When the view is rendered, the `$posts` view variable will be serialized 
 29:  * into JSON.
 30:  *
 31:  * You can also define `'_serialize'` as an array.  This will create a top level object containing
 32:  * all the named view variables:
 33:  *
 34:  * {{{
 35:  * $this->set(compact('posts', 'users', 'stuff'));
 36:  * $this->set('_serialize', array('posts', 'users'));
 37:  * }}}
 38:  * 
 39:  * The above would generate a JSON object that looks like:
 40:  *
 41:  * `{"posts": [...], "users": [...]}`
 42:  *
 43:  * If you don't use the `_serialize` key, you will need a view.  You can use extended
 44:  * views to provide layout like functionality.
 45:  *
 46:  * @package       Cake.View
 47:  * @since         CakePHP(tm) v 2.1.0
 48:  */
 49: class JsonView extends View {
 50: 
 51: /**
 52:  * JSON views are always located in the 'json' sub directory for a 
 53:  * controllers views.
 54:  * 
 55:  * @var string
 56:  */
 57:     public $subDir = 'json';
 58: 
 59: /**
 60:  * Constructor
 61:  *
 62:  * @param Controller $controller
 63:  */
 64:     public function __construct(Controller $controller = null) {
 65:         parent::__construct($controller);
 66:         if (isset($controller->response) && $controller->response instanceof CakeResponse) {
 67:             $controller->response->type('json');
 68:         }
 69:     }
 70: 
 71: /**
 72:  * Render a JSON view.
 73:  *
 74:  * Uses the special '_serialize' parameter to convert a set of
 75:  * view variables into a JSON response.  Makes generating simple 
 76:  * JSON responses very easy.  You can omit the '_serialize' parameter, 
 77:  * and use a normal view + layout as well.
 78:  *
 79:  * @param string $view The view being rendered.
 80:  * @param string $layout The layout being rendered.
 81:  * @return string The rendered view.
 82:  */
 83:     public function render($view = null, $layout = null) {
 84:         if (isset($this->viewVars['_serialize'])) {
 85:             $serialize = $this->viewVars['_serialize'];
 86:             if (is_array($serialize)) {
 87:                 $data = array();
 88:                 foreach ($serialize as $key) {
 89:                     $data[$key] = $this->viewVars[$key];
 90:                 }
 91:             } else {
 92:                 $data = isset($this->viewVars[$serialize]) ? $this->viewVars[$serialize] : null;
 93:             }
 94:             $content = json_encode($data);
 95:             $this->Blocks->set('content', $content);
 96:             return $content;
 97:         }
 98:         if ($view !== false && $viewFileName = $this->_getViewFileName($view)) {
 99:             if (!$this->_helpersLoaded) {
100:                 $this->loadHelpers();
101:             }
102:             $content = $this->_render($viewFileName);
103:             $this->Blocks->set('content', $content);
104:             return $content;
105:         }
106:     }
107: 
108: }
109: