Add a more robust plugin config system.

2010-11-20: Luke Shumaker <lukeshu@sbcglobal.net>
Add a more robust (but backward compatible) plugin config system
 * lib/util.php: add common_config_section($main), as a companion to common_config($main,$sub)
 * lib/statusnet.php:
    Functions for other Places:
      - add public static pluginFiles($name) which returns a list of all possible filenames a plugin with $name could be defined in.
      - addPlugin(...): use self::pluginFiles(...) instead of a hard-coded list.
    Actual Functionality:
      - add public static getPlugins() which returns
          array_merge(
            common_config('plugins','default'),
            common_config_section('plugin-list')
          )
      - use self::getPlugins() instead of common_config('plugins','default')
    Robustness:
      - handle plugins that have a type other than "array" or "null" for parameters without bugging out
 * actions/pluginenable.php: (in order of in the file):
    - use StatusNet::getPlugins() instead of common_config('plugins','default')
    - check if a plugin exists, not whether it is loaded (uses newly added StatusNet::pluginFiles(...))
    - Also save to 'plugin-list' (the new plugin system), in addition to 'plugins' (the old plugin system)

2 files changed, 48 insertions, 11 deletions

diff --git a/lib/statusnet.php b/lib/statusnet.php
index 4c2aacd8f..099894455 100644
--- a/lib/statusnet.php
+++ b/lib/statusnet.php
@@ -34,6 +34,25 @@ class StatusNet
     protected static $plugins = array();
 
     /**
+     * Return a list of possible filenames that plugin $name can be in.
+     *
+     * @param string $name class name & plugin file/subdir name
+     */
+    public static function pluginFiles($name) {
+        $name = ucfirst($name);
+        $pluginclass = "{$name}Plugin";
+
+        $files = array("local/plugins/{$pluginclass}.php",
+                       "local/plugins/{$name}/{$pluginclass}.php",
+                       "local/{$pluginclass}.php",
+                       "local/{$name}/{$pluginclass}.php",
+                       "plugins/{$pluginclass}.php",
+                       "plugins/{$name}/{$pluginclass}.php");
+
+        return $files;
+    }
+
+    /**
      * Configure and instantiate a plugin into the current configuration.
      * Class definitions will be loaded from standard paths if necessary.
      * Note that initialization events won't be fired until later.
@@ -50,12 +69,7 @@ class StatusNet
 
         if (!class_exists($pluginclass)) {
 
-            $files = array("local/plugins/{$pluginclass}.php",
-                           "local/plugins/{$name}/{$pluginclass}.php",
-                           "local/{$pluginclass}.php",
-                           "local/{$name}/{$pluginclass}.php",
-                           "plugins/{$pluginclass}.php",
-                           "plugins/{$name}/{$pluginclass}.php");
+            $files = self::pluginFiles($name);
 
             foreach ($files as $file) {
                 $fullpath = INSTALLDIR.'/'.$file;
@@ -168,22 +182,37 @@ class StatusNet
         }
         return $sites;
     }
+    /**
+     * Return a list of plugins that are currently in the system.
+     *
+     * This means default plugins, plugins that are explicitly enabled, or
+     * plugins that are explicitly disabled.
+     */
+
+    public static function getPlugins() {
+        // Default plugins
+        $pluginlist = common_config('plugins', 'default');
+        // Enabled plugins
+        $enabled=common_config_section('plugin-list');
+        if ($enabled) {
+            $pluginlist = array_merge($pluginlist,$enabled);
+        }  
+        return $pluginlist;
+    }
 
     /**
      * Fire initialization events for all instantiated plugins.
      */
     protected static function initPlugins()
     {
-        // Load default plugins
-        foreach (common_config('plugins', 'default') as $name => $params) {
+        // Load plugins
+        foreach (self::getPlugins() as $name => $params) {
             $key = 'disable-' . $name;
             if (common_config('plugins', $key)) {
                 continue;
             }
 
-            if (is_null($params)) {
-                addPlugin($name);
-            } else if (is_array($params)) {
+            if (is_array($params)) {
                 if (count($params) == 0) {
                     addPlugin($name);
                 } else {
@@ -196,6 +225,8 @@ class StatusNet
                         }
                     }
                 }
+            } else {
+                addPlugin($name);
             }
         }
 
diff --git a/lib/util.php b/lib/util.php
index 3d4adcf4b..379516529 100644
--- a/lib/util.php
+++ b/lib/util.php
@@ -1857,6 +1857,12 @@ function common_config($main, $sub)
             array_key_exists($sub, $config[$main])) ? $config[$main][$sub] : false;
 }
 
+function common_config_section($main)
+{
+    global $config;
+    return array_key_exists($main, $config) ? $config[$main] : false;
+}
+
 /**
  * Pull arguments from a GET/POST/REQUEST array with first-level input checks:
  * strips "magic quotes" slashes if necessary, and kills invalid UTF-8 strings.