CRM/Core/CommunityMessages.php

   1 <?php
   2 /*
   3  +--------------------------------------------------------------------+
   4  | CiviCRM version 4.5                                                |
   5  +--------------------------------------------------------------------+
   6  | Copyright CiviCRM LLC (c) 2004-2014                                |
   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 = 'https://alert.civicrm.org/alert?prot=1&ver={ver}&uf={uf}&sid={sid}&lang={lang}&co={co}';
  34   const DEFAULT_PERMISSION = 'administer CiviCRM';
  35
  36   /**
  37    * Default time to wait before retrying
  38    */
  39   const DEFAULT_RETRY = 7200; // 2 hours
  40
  41   /**
  42    * @var CRM_Utils_HttpClient
  43    */
  44   protected $client;
  45
  46   /**
  47    * @var CRM_Utils_Cache_Interface
  48    */
  49   protected $cache;
  50
  51   /**
  52    * @var FALSE|string
  53    */
  54   protected $messagesUrl;
  55
  56   /**
  57    * Create default instance
  58    *
  59    * @return CRM_Core_CommunityMessages
  60    */
  61   public static function create() {
  62     return new CRM_Core_CommunityMessages(
  63       new CRM_Utils_Cache_SqlGroup(array(
  64         'group' => 'community-messages',
  65         'prefetch' => FALSE,
  66       )),
  67       CRM_Utils_HttpClient::singleton()
  68     );
  69   }
  70
  71   /**
  72    * @param CRM_Utils_Cache_Interface $cache
  73    * @param CRM_Utils_HttpClient $client
  74    * @param null $messagesUrl
  75    */
  76   public function __construct($cache, $client, $messagesUrl = NULL) {
  77     $this->cache = $cache;
  78     $this->client = $client;
  79     if ($messagesUrl === NULL) {
  80       $this->messagesUrl = CRM_Core_BAO_Setting::getItem(CRM_Core_BAO_Setting::SYSTEM_PREFERENCES_NAME, 'communityMessagesUrl', NULL, '*default*');
  81     }
  82     else {
  83       $this->messagesUrl = $messagesUrl;
  84     }
  85     if ($this->messagesUrl === '*default*') {
  86       $this->messagesUrl = self::DEFAULT_MESSAGES_URL;
  87     }
  88   }
  89
  90   /**
  91    * Get the messages document (either from the cache or by downloading)
  92    *
  93    * @return NULL|array
  94    */
  95   public function getDocument() {
  96     $isChanged = FALSE;
  97     $document = $this->cache->get('communityMessages');
  98
  99     if (empty($document) || !is_array($document)) {
 100       $document = array(
 101         'messages' => array(),
 102         'expires' => 0, // ASAP
 103         'ttl' => self::DEFAULT_RETRY,
 104         'retry' => self::DEFAULT_RETRY,
 105       );
 106       $isChanged = TRUE;
 107     }
 108
 109     if ($document['expires'] <= CRM_Utils_Time::getTimeRaw()) {
 110       $newDocument = $this->fetchDocument();
 111       if ($newDocument && $this->validateDocument($newDocument)) {
 112         $document = $newDocument;
 113         $document['expires'] = CRM_Utils_Time::getTimeRaw() + $document['ttl'];
 114       }
 115       else {
 116         // keep the old messages for now, try again later
 117         $document['expires'] = CRM_Utils_Time::getTimeRaw() + $document['retry'];
 118       }
 119       $isChanged = TRUE;
 120     }
 121
 122     if ($isChanged) {
 123       $this->cache->set('communityMessages', $document);
 124     }
 125
 126     return $document;
 127   }
 128
 129   /**
 130    * Download document from URL and parse as JSON
 131    *
 132    * @return NULL|array parsed JSON
 133    */
 134   public function fetchDocument() {
 135     list($status, $json) = $this->client->get($this->getRenderedUrl());
 136     if ($status != CRM_Utils_HttpClient::STATUS_OK || empty($json)) {
 137       return NULL;
 138     }
 139     $doc = json_decode($json, TRUE);
 140     if (empty($doc) || json_last_error() != JSON_ERROR_NONE) {
 141       return NULL;
 142     }
 143     return $doc;
 144   }
 145
 146   /**
 147    * Get the final, usable URL string (after interpolating any variables)
 148    *
 149    * @return FALSE|string
 150    */
 151   public function getRenderedUrl() {
 152     return CRM_Utils_System::evalUrl($this->messagesUrl);
 153   }
 154
 155   /**
 156    * @return bool
 157    */
 158   public function isEnabled() {
 159     return $this->messagesUrl !== FALSE && $this->messagesUrl !== 'FALSE';
 160   }
 161
 162   /**
 163    * Pick a message to display
 164    *
 165    * @return NULL|array
 166    */
 167   public function pick() {
 168     $document = $this->getDocument();
 169     $messages = array();
 170     foreach ($document['messages'] as $message) {
 171       if (!isset($message['perms'])) {
 172         $message['perms'] = array(self::DEFAULT_PERMISSION);
 173       }
 174       if (!CRM_Core_Permission::checkAnyPerm($message['perms'])) {
 175         continue;
 176       }
 177
 178       if (isset($message['components'])) {
 179         $enabled = array_keys(CRM_Core_Component::getEnabledComponents());
 180         if (count(array_intersect($enabled, $message['components'])) == 0) {
 181           continue;
 182         }
 183       }
 184
 185       $messages[] = $message;
 186     }
 187     if (empty($messages)) {
 188       return NULL;
 189     }
 190
 191     $idx = rand(0, count($messages) - 1);
 192     return $messages[$idx];
 193   }
 194
 195   /**
 196    * @param string $markup
 197    * @return string
 198    */
 199   public static function evalMarkup($markup) {
 200     $config = CRM_Core_Config::singleton();
 201     $vals = array(
 202       'resourceUrl' => rtrim($config->resourceBase, '/'),
 203       'ver' => CRM_Utils_System::version(),
 204       'uf' => $config->userFramework,
 205       'php' => phpversion(),
 206       'sid' => md5('sid_' . (defined('CIVICRM_SITE_KEY') ? CIVICRM_SITE_KEY : '') . '_' . $config->userFrameworkBaseURL),
 207       'baseUrl' => $config->userFrameworkBaseURL,
 208       'lang' => $config->lcMessages,
 209       'co' => $config->defaultContactCountry,
 210     );
 211     $vars = array();
 212     foreach ($vals as $k => $v) {
 213       $vars['%%' . $k . '%%'] = $v;
 214       $vars['{{' . $k . '}}'] = urlencode($v);
 215     }
 216     return strtr($markup, $vars);
 217   }
 218
 219   /**
 220    * Ensure that a document is well-formed
 221    *
 222    * @param array $document
 223    * @return bool
 224    */
 225   public function validateDocument($document) {
 226     if (!isset($document['ttl']) || !is_integer($document['ttl'])) {
 227       return FALSE;
 228     }
 229     if (!isset($document['retry']) || !is_integer($document['retry'])) {
 230       return FALSE;
 231     }
 232     if (!isset($document['messages']) || !is_array($document['messages'])) {
 233       return FALSE;
 234     }
 235     foreach ($document['messages'] as $message) {
 236       // TODO validate $message['markup']
 237     }
 238
 239     return TRUE;
 240   }
 241
 242 }