Allow a plugin to update phplist (#946)

* Allow a plugin to update the phplist code

* When a new release is available link to a plugin if available in preference to the updater

Author: bramley

public_html/lists/admin/Updater.php

@@ -0,0 +1,8 @@
+<?php
+/**
+ * A plugin should implement this interface if it wants to be responsible for updating phpList.
+ * It should implement an admin page with the name "update".
+ */
+interface Updater
+{
+}

public_html/lists/admin/index.php

@@ -523,24 +523,25 @@ function mb_strtolower($string)
         echo Info($GLOBALS['I18N']->get('Running in testmode, no emails will be sent. Check your config file.'));
     }
 
- #   if (!DEVVERSION) { ## why not, quite useful to see
-    if (ALLOW_UPDATER) {
+    if (ALLOW_UPDATER || $updaterplugin) {
         $updaterdir = __DIR__ . '/../updater';
 
         include 'updateLib.php';
         $updateNotif = checkForUpdate();
-        $moreInfo = ' <ul><li><a href="https://www.phplist.com/download?utm_source=pl' . VERSION . '&amp;utm_medium=updatedownload&amp;utm_campaign=phpList" title="' . s('Download the new version') . '" target="_blank">' . s('Download the new version') . '</a></li>';
 
-        if (file_exists($updaterdir)) {
-            $moreInfo .= '<li>'.s('or use the %sphpList Updater%s','<a href="?page=update" title="' . s('automatic updater') . '">','</a>');
-        }
-        $moreInfo .= '</ul>';
+        if ($updateNotif !== '' && $_GET['page'] !== 'update') {
+            $moreInfo = ' <ul><li><a href="https://www.phplist.com/download?utm_source=pl' . VERSION . '&amp;utm_medium=updatedownload&amp;utm_campaign=phpList" title="' . s('Download the new version') . '" target="_blank">' . s('Download the new version') . '</a></li>';
 
-        if ($updateNotif !== '') {
+            if ($updaterplugin) {
+                $class = get_class($updaterplugin);
+                $moreInfo .= '<li>'.s('or use the %sphpList Updater%s', sprintf('<a href="?page=update&amp;pi=%s" title="', $class) . s('automatic updater') . '">','</a>');
+            } elseif (file_exists($updaterdir)) {
+                $moreInfo .= '<li>'.s('or use the %sphpList Updater%s','<a href="?page=update" title="' . s('automatic updater') . '">','</a>');
+            }
+            $moreInfo .= '</ul>';
             Info($updateNotif . '' . $moreInfo);
         }
     }
-#   }
 
     if (version_compare(PHP_VERSION, '5.3.3', '<') && WARN_ABOUT_PHP_SETTINGS) {
         Error(s('Your PHP version is out of date. phpList requires PHP version 5.3.3 or higher.'));

public_html/lists/admin/pluginlib.php

@@ -4,12 +4,14 @@
 require_once dirname(__FILE__).'/EmailSender.php';
 include_once dirname(__FILE__).'/defaultplugin.php';
 require_once dirname(__FILE__).'/AnalyticsQuery.php';
+require_once dirname(__FILE__).'/Updater.php';
 
 $GLOBALS['plugins'] = array();
 $GLOBALS['editorplugin'] = false;
 $GLOBALS['authenticationplugin'] = false;
 $GLOBALS['emailsenderplugin'] = false;
 $GLOBALS['analyticsqueryplugin'] = false;
+$GLOBALS['updaterplugin'] = false;
 
 $pluginRootDirs = array();
 if (PLUGIN_ROOTDIRS != '') {
@@ -123,6 +125,10 @@
                         $default_config['analytic_tracker']['values'] += array('plugin' => $analyticsqueryplugin->name);
                     }
 
+                    if (!$GLOBALS['updaterplugin'] && $pluginInstance instanceof Updater) {
+                        $GLOBALS['updaterplugin'] = $pluginInstance;
+                    }
+
                     if (!empty($pluginInstance->DBstruct)) {
                         foreach ($pluginInstance->DBstruct as $tablename => $tablecolumns) {
                             $GLOBALS['tables'][$className.'_'.$tablename] = $GLOBALS['table_prefix'].$className.'_'.$tablename;