CRM/Core/CommunityMessages.php

   1 <?php
   2 /*
   3  +--------------------------------------------------------------------+
   4  | CiviCRM version 4.3                                                |
   5  +--------------------------------------------------------------------+
   6  | Copyright CiviCRM LLC (c) 2004-2013                                |
   7  +--------------------------------------------------------------------+
   8  | This file is a part of CiviCRM.                                    |
   9  |                                                                    |
  10  | CiviCRM is free software; you can copy, modify, and distribute it  |
  11  | under the terms of the GNU Affero General Public License           |
  12  | Version 3, 19 November 2007 and the CiviCRM Licensing Exception.   |
  13  |                                                                    |
  14  | CiviCRM is distributed in the hope that it will be useful, but     |
  15  | WITHOUT ANY WARRANTY; without even the implied warranty of         |
  16  | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.               |
  17  | See the GNU Affero General Public License for more details.        |
  18  |                                                                    |
  19  | You should have received a copy of the GNU Affero General Public   |
  20  | License and the CiviCRM Licensing Exception along                  |
  21  | with this program; if not, contact CiviCRM LLC                     |
  22  | at info[AT]civicrm[DOT]org. If you have questions about the        |
  23  | GNU Affero General Public License or the licensing of CiviCRM,     |
  24  | see the CiviCRM license FAQ at http://civicrm.org/licensing        |
  25  +--------------------------------------------------------------------+
  26 */
  27
  28 /**
  29  * Manage the download, validation, and rendering of community messages
  30  */
  31 class CRM_Core_CommunityMessages {
  32
  33   const DEFAULT_MESSAGES_URL = 'http://alert.civicrm.org/alert?prot=1&ver={ver}&uf={uf}&sid={sid}';
  34
  35   /**
  36    * Default time to wait before retrying
  37    */
  38   const DEFAULT_RETRY = 7200; // 2 hours
  39
  40   /**
  41    * @var CRM_Utils_HttpClient
  42    */
  43   protected $client;
  44
  45   /**
  46    * @var CRM_Utils_Cache_Interface
  47    */
  48   protected $cache;
  49
  50   /**
  51    * @var FALSE|string
  52    */
  53   protected $messagesUrl;
  54
  55   /**
  56    * @param CRM_Utils_Cache_Interface $cache
  57    * @param CRM_Utils_HttpClient $client
  58    */
  59   public function __construct($cache, $client, $messagesUrl = NULL) {
  60     $this->cache = $cache;
  61     $this->client = $client;
  62     if ($messagesUrl === NULL) {
  63       $this->messagesUrl = CRM_Core_BAO_Setting::getItem(CRM_Core_BAO_Setting::SYSTEM_PREFERENCES_NAME, 'community_messages_url', NULL, self::DEFAULT_MESSAGES_URL);
  64     }
  65     else {
  66       $this->messagesUrl = $messagesUrl;
  67     }
  68   }
  69
  70   /**
  71    * Get the messages document
  72    *
  73    * @return NULL|array
  74    */
  75   public function getDocument() {
  76     if ($this->messagesUrl === FALSE) {
  77       return NULL;
  78     }
  79
  80     $isChanged = FALSE;
  81     $document = $this->cache->get('communityMessages');
  82
  83     if (empty($document) || !is_array($document)) {
  84       $document = array(
  85         'messages' => array(),
  86         'expires' => 0, // ASAP
  87         'ttl' => self::DEFAULT_RETRY,
  88         'retry' => self::DEFAULT_RETRY,
  89       );
  90       $isChanged = TRUE;
  91     }
  92
  93     if ($document['expires'] <= CRM_Utils_Time::getTimeRaw()) {
  94       $newDocument = $this->fetchDocument($this->messagesUrl);
  95       if ($newDocument) {
  96         $document = $newDocument;
  97         $document['expires'] = CRM_Utils_Time::getTimeRaw() + $document['ttl'];
  98       }
  99       else {
 100         $document['expires'] = CRM_Utils_Time::getTimeRaw() + $document['retry'];
 101       }
 102       $isChanged = TRUE;
 103     }
 104
 105     if ($isChanged) {
 106       $this->cache->set('communityMessages', $document);
 107     }
 108
 109     return $document;
 110   }
 111
 112   /**
 113    * Download document from URL and parse as JSON
 114    *
 115    * @param string $url
 116    * @return NULL|array parsed JSON
 117    */
 118   public function fetchDocument($url) {
 119     list($status, $json) = $this->client->get(CRM_Utils_System::evalUrl($url));
 120     if ($status != CRM_Utils_HttpClient::STATUS_OK || empty($json)) {
 121       return NULL;
 122     }
 123     $doc = json_decode($json, TRUE);
 124     if (empty($doc) || json_last_error() != JSON_ERROR_NONE) {
 125       return NULL;
 126     }
 127     return $doc;
 128   }
 129
 130   /**
 131    * Pick one message
 132    *
 133    * @param callable $permChecker
 134    * @param array $components
 135    * @return NULL|array
 136    */
 137   public function pick($permChecker, $components) {
 138     throw new Exception('not implemented');
 139   }
 140
 141   /**
 142    * @param string $markup
 143    * @return string
 144    */
 145   public static function evalMarkup($markup) {
 146     throw new Exception('not implemented');
 147   }
 148
 149 }