MDL-39088 add new general uninstall url support to plugin manager

admin/renderer.php

@@ -375,7 +375,7 @@ class core_admin_renderer extends plugin_renderer_base {
      * Display a page to confirm the plugin uninstallation.
      *
      * @param plugin_manager $pluginman
-     * @param plugin_info $pluginfo
+     * @param plugininfo_base $pluginfo
      * @param moodle_url $continueurl URL to continue after confirmation
      * @return string
      */
@@ -384,10 +384,14 @@ class core_admin_renderer extends plugin_renderer_base {
 
         $pluginname = $pluginman->plugin_name($pluginfo->component);
 
+        $confirm = '<p>' . get_string('uninstallconfirm', 'core_plugin', array('name' => $pluginname)) . '</p>';
+        if ($extraconfirm = $pluginfo->get_uninstall_extra_warning()) {
+            $confirm .= $extraconfirm;
+        }
+
         $output .= $this->output->header();
         $output .= $this->output->heading(get_string('uninstalling', 'core_plugin', array('name' => $pluginname)));
-        $output .= $this->output->confirm(get_string('uninstallconfirm', 'core_plugin', array('name' => $pluginname)),
-            $continueurl, $this->page->url);
+        $output .= $this->output->confirm($confirm, $continueurl, $this->page->url);
         $output .= $this->output->footer();
 
         return $output;
@@ -397,7 +401,7 @@ class core_admin_renderer extends plugin_renderer_base {
      * Display a page with results of plugin uninstallation and offer removal of plugin files.
      *
      * @param plugin_manager $pluginman
-     * @param plugin_info $pluginfo
+     * @param plugininfo_base $pluginfo
      * @param progress_trace_buffer $progress
      * @param moodle_url $continueurl URL to continue to remove the plugin folder
      * @return string
@@ -431,7 +435,7 @@ class core_admin_renderer extends plugin_renderer_base {
      * Display a page with results of plugin uninstallation and inform about the need to remove plugin files manually.
      *
      * @param plugin_manager $pluginman
-     * @param plugin_info $pluginfo
+     * @param plugininfo_base $pluginfo
      * @param progress_trace_buffer $progress
      * @return string
      */

lib/adminlib.php

@@ -115,6 +115,8 @@ define('INSECURE_DATAROOT_ERROR', 2);
 /**
  * Automatically clean-up all plugin data and remove the plugin DB tables
  *
+ * NOTE: do not call directly, use new /admin/plugins.php?uninstall=component instead!
+ *
  * @param string $type The plugin type, eg. 'mod', 'qtype', 'workshopgrading' etc.
  * @param string $name The plugin name, eg. 'forum', 'multichoice', 'accumulative' etc.
  * @uses global $OUTPUT to produce notices and other messages

lib/pluginlib.php

@@ -520,6 +520,26 @@ class plugin_manager {
         return true;
     }
 
+    /**
+     * Returns uninstall URL if exists.
+     *
+     * @param string $component
+     * @return moodle_url uninstall URL, null if uninstall not supported
+     */
+    public function get_uninstall_url($component) {
+        if (!$this->can_uninstall_plugin($component)) {
+            return null;
+        }
+
+        $pluginfo = $this->get_plugin_info($component);
+
+        if (is_null($pluginfo)) {
+            return null;
+        }
+
+        return $pluginfo->get_uninstall_url();
+    }
+
     /**
      * Uninstall the given plugin.
      *
@@ -2825,6 +2845,15 @@ abstract class plugininfo_base {
         return true;
     }
 
+    /**
+     * Optional extra warning before uninstallation, for example number of uses in courses.
+     *
+     * @return string
+     */
+    public function get_uninstall_extra_warning() {
+        return '';
+    }
+
     /**
      * Returns the URL of the screen where this plugin can be uninstalled
      *