Merge pull request #4 from Soflomo/feature/pretty-print-json

Add listener to print JSON to Pretty Print

src/Common/Mvc/View/PrettyPrintJsonListener.php

@@ -0,0 +1,99 @@
+<?php
+/**
+ * Copyright (c) 2014 Jurian Sluiman.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   * Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in
+ *     the documentation and/or other materials provided with the
+ *     distribution.
+ *
+ *   * Neither the names of the copyright holders nor the names of the
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * @author      Jurian Sluiman <jurian@soflomo.com>
+ * @copyright   2014 Jurian Sluiman.
+ * @license     http://www.opensource.org/licenses/bsd-license.php  BSD License
+ * @link        http://soflomo.com
+ */
+
+namespace Soflomo\Common\Mvc\View;
+
+use Zend\Mvc\MvcEvent;
+use Zend\Json\Json;
+
+/**
+ * Pretty-Print JSON responses
+ *
+ * Attach this listener to the MvcEvent::EVENT_FINISH event to
+ * modify the reponse. The listener will check whether the type
+ * of the response is application/json. If so, a requets header
+ * X-Pretty-Json must be send by the client. If both are true,
+ * the response will be modified to pretty print the JSON string.
+ *
+ * Usage:
+ * <code>
+ * public function onBootstrap(MvcEvent $e)
+ * {
+ *     $app = $e->getApplication();
+ *     $em  = $app->getEventManager();
+ *
+ *     $listener = new PrettyPrintJsonListener;
+ *     $em->attach(MvcEvent::EVENT_FINISH, $listener);
+ * }
+ * </code>
+ */
+class PrettyPrintJsonListener
+{
+    /**
+     * Invoked by event manager
+     *
+     * @param  MvcEvent $e
+     * @return void
+     */
+    public function __invoke(MvcEvent $e)
+    {
+        $response = $e->getResponse();
+        $headers  = $response->getHeaders();
+        if (!$headers->has('Content-Type')) {
+            return;
+        }
+
+        $contentType = $headers->get('Content-Type');
+        if (false !== strpos('application/json', $contentType->getFieldValue())) {
+            return;
+        }
+
+        $request = $e->getRequest();
+        $headers = $request->getHeaders();
+        if (!$headers->has('X-Pretty-Json')) {
+            return;
+        }
+
+        $body = $response->getContent();
+        $body = Json::prettyPrint($body, array('indent' => '  '));
+        $body = $body . "\n";
+        $response->setContent($body);
+    }
+}