Merge pull request joomla#50 from Lemings/patch-3

Thiis adds nested tag form field to administrator/tag view.

administrator/components/com_tags/models/forms/tag.xml

@@ -20,7 +20,7 @@
 
 	<field
 		name="parent_id"
-		type="tag"
+		type="tagnested"
 		label="COM_TAGS_FIELD_PARENT_LABEL"
 		description="COM_TAGS_FIELD_PARENT_DESC"
 		validate="notequals"

libraries/cms/form/field/tagnested.php

@@ -0,0 +1,77 @@
+<?php
+/**
+ * @package     Joomla.Administrator
+ * @subpackage  com_tags
+ *
+ * @copyright   Copyright (C) 2005 - 2013 Open Source Matters, Inc. All rights reserved.
+ * @license     GNU General Public License version 2 or later; see LICENSE.txt
+ */
+
+defined('JPATH_BASE') or die;
+
+JFormHelper::loadFieldClass('tag');
+
+/**
+ * Form Field class for the Joomla Framework.
+ *
+ * @package     Joomla.Administrator
+ * @subpackage  com_tags
+ * @since       3.1
+ */
+class JFormFieldTagNested extends JFormFieldTag
+{
+	/**
+	 * A flexible tag list that respects access controls
+	 *
+	 * @var    string
+	 * @since  3.1
+	 */
+	public $type = 'TagNested';
+
+	/**
+	 * An array of tags
+	 *
+	 * @var    string
+	 * @since  3.1
+	 */
+	public $tags;
+
+		/**
+	 * Method to get the field input for a tag field.
+	 *
+	 * @return  string  The field input.
+	 *
+	 * @since   3.1
+	 */
+	protected function getInput()
+	{
+		// This value is replaced with JTags object to fake parent tag formfield, othervise it is set to array ()
+		$newValue = new JTags;
+		$newValue->tags = $this->value;
+		$this->value = $newValue;
+
+		$input = parent::getInput();
+
+		return $input;
+	}
+
+	/**
+	 * Method to get a list of tags
+	 *
+	 * @return  array  The field option objects.
+	 * @since   3.1
+	 */
+	protected function getOptions()
+	{
+		$options = parent::getOptions();
+
+		// Add "-" before nested tags, depending on level 
+		foreach ($options as &$option)
+		{
+			$repeat = (isset($option->level) && $option->level - 1 >= 0) ? $option->level - 1 : 0;
+			$option->text = str_repeat('- ', $repeat) . $option->text;
+		}
+
+		return $options;
+	}
+}