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 and layouts if you 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:  * You can also enable JSONP support by setting parameter `_jsonp` to true or a string to specify
 48:  * custom query string paramater name which will contain the callback function name.
 49:  *
 50:  * @package       Cake.View
 51:  * @since         CakePHP(tm) v 2.1.0
 52:  */
 53: class JsonView extends View {
 54: 
 55: /**
 56:  * JSON views are always located in the 'json' sub directory for
 57:  * controllers' views.
 58:  *
 59:  * @var string
 60:  */
 61:     public $subDir = 'json';
 62: 
 63: /**
 64:  * Constructor
 65:  *
 66:  * @param Controller $controller
 67:  */
 68:     public function __construct(Controller $controller = null) {
 69:         parent::__construct($controller);
 70:         if (isset($controller->response) && $controller->response instanceof CakeResponse) {
 71:             $controller->response->type('json');
 72:         }
 73:     }
 74: 
 75: /**
 76:  * Skip loading helpers if this is a _serialize based view.
 77:  *
 78:  * @return void
 79:  */
 80:     public function loadHelpers() {
 81:         if (isset($this->viewVars['_serialize'])) {
 82:             return;
 83:         }
 84:         parent::loadHelpers();
 85:     }
 86: 
 87: /**
 88:  * Render a JSON view.
 89:  *
 90:  * ### Special parameters
 91:  * `_serialize` To convert a set of view variables into a JSON response.
 92:  *   Its value can be a string for single variable name or array for multiple names.
 93:  *   You can omit the`_serialize` parameter, and use a normal view + layout as well.
 94:  * `_jsonp` Enables JSONP support and wraps response in callback function provided in query string.
 95:  *   - Setting it to true enables the default query string parameter "callback".
 96:  *   - Setting it to a string value, uses the provided query string parameter for finding the
 97:  *     JSONP callback name.
 98:  *
 99:  * @param string $view The view being rendered.
100:  * @param string $layout The layout being rendered.
101:  * @return string The rendered view.
102:  */
103:     public function render($view = null, $layout = null) {
104:         $return = null;
105:         if (isset($this->viewVars['_serialize'])) {
106:             $return = $this->_serialize($this->viewVars['_serialize']);
107:         } elseif ($view !== false && $this->_getViewFileName($view)) {
108:             $return = parent::render($view, false);
109:         }
110: 
111:         if (!empty($this->viewVars['_jsonp'])) {
112:             $jsonpParam = $this->viewVars['_jsonp'];
113:             if ($this->viewVars['_jsonp'] === true) {
114:                 $jsonpParam = 'callback';
115:             }
116:             if (isset($this->request->query[$jsonpParam])) {
117:                 $return = sprintf('%s(%s)', h($this->request->query[$jsonpParam]), $return);
118:                 $this->response->type('js');
119:             }
120:         }
121: 
122:         return $return;
123:     }
124: 
125: /**
126:  * Serialize view vars
127:  *
128:  * @param array $serialize The viewVars that need to be serialized
129:  * @return string The serialized data
130:  */
131:     protected function _serialize($serialize) {
132:         if (is_array($serialize)) {
133:             $data = array();
134:             foreach ($serialize as $alias => $key) {
135:                 if (is_numeric($alias)) {
136:                     $alias = $key;
137:                 }
138:                 if (array_key_exists($key, $this->viewVars)) {
139:                     $data[$alias] = $this->viewVars[$key];
140:                 }
141:             }
142:             $data = !empty($data) ? $data : null;
143:         } else {
144:             $data = isset($this->viewVars[$serialize]) ? $this->viewVars[$serialize] : null;
145:         }
146: 
147:         if (version_compare(PHP_VERSION, '5.4.0', '>=') && Configure::read('debug')) {
148:             return json_encode($data, JSON_PRETTY_PRINT);
149:         }
150: 
151:         return json_encode($data);
152:     }
153: 
154: }
155: