Add hierarhical managment

backend/wordpress/wp-content/plugins/groups/lib/admin/groups-admin-tree-view.php

@@ -0,0 +1,54 @@
+<?php
+/**
+ * groups-admin-tree-view.php
+ *
+ * Copyright (c) "kento" Karim Rahimpur www.itthinx.com
+ *
+ * This code is released under the GNU General Public License.
+ * See COPYRIGHT.txt and LICENSE.txt.
+ *
+ * This code is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * This header and all notices must be kept intact.
+ *
+ * @author Karim Rahimpur
+ * @package groups
+ * @since groups 1.0.0
+ */
+
+if ( !defined( 'ABSPATH' ) ) {
+	exit;
+}
+
+/**
+ * Tree view : a simple tree view
+ */
+function groups_admin_tree_view() {
+
+	global $wpdb;
+
+	$output = '';
+	$today = date( 'Y-m-d', time() );
+
+	if ( !current_user_can( GROUPS_ACCESS_GROUPS ) ) {
+		wp_die( __( 'Access denied.', 'groups' ) );
+	}
+
+	$output .=
+		'<div class="groups-tree-view">' .
+		'<h1>' .
+		__( 'Tree of Groups', 'groups' ) .
+		'</h1>';
+
+	$tree = Groups_Utility::get_group_tree();
+	$tree_output = '';
+	Groups_Utility::render_group_tree( $tree, $tree_output );
+	$output .= $tree_output;
+
+	$output .= '</div>'; // .groups-tree-view
+
+	echo $output;
+} // function groups_admin_tree_view()