Recursive deletion from index if a page is deleted

Fixes #8.

algolia.php

@@ -63,7 +63,7 @@ function algolia() {
   });
 
   kirby()->hook('panel.page.delete', function($page) {
-    return algolia()->deletePage($page);
+    return algolia()->deletePageRecursive($page);
   });
 
   kirby()->hook('panel.page.sort', function($page) {

lib/algolia.php

@@ -149,7 +149,6 @@ public function movePage(Page $oldPage, Page $newPage) {
 
   /**
    * Deletes a page from the index
-   * Used by Panel hooks
    *
    * @param Page|string $id Kirby page or page ID
    */
@@ -159,6 +158,22 @@ public function deletePage($id) {
     $this->getIndex()->deleteObject($id);
   }
 
+  /**
+   * Deletes a page and all its children from the index
+   * Used by Panel hooks
+   *
+   * @param Page|string $page Kirby page or page ID
+   */
+  public function deletePageRecursive($page) {
+    if(is_string($page)) $page = page($page);
+    if(!$page) return false;
+
+    $this->deletePage($page);
+    foreach($page->children() as $p) {
+      $this->deletePageRecursive($p);
+    }
+  }
+
   /**
    * Checks if a specific page should be included in the Algolia index
    * Uses the configuration option algolia.templates