From 26151f2e4c8f8d667f8e6e7625c47cedaffac189 Mon Sep 17 00:00:00 2001
From: Ingo Schommer <ingo@silverstripe.com>
Date: Sun, 8 May 2011 23:36:55 +1200
Subject: [PATCH] ENHANCEMENT Limiting page types based on
 SiteTree::$allowed_children in CMSMain.AddForm.js

---
 code/controller/CMSMain.php   |  3 ++
 javascript/CMSMain.AddForm.js | 52 ++++++++++++++++++++++++++++++++++-
 2 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/code/controller/CMSMain.php b/code/controller/CMSMain.php
index 3d59203e..8293ec21 100755
--- a/code/controller/CMSMain.php
+++ b/code/controller/CMSMain.php
@@ -1297,6 +1297,8 @@ JS;
 		
 		$fields = new FieldSet(
 			// new HiddenField("ParentID", false, ($this->parentRecord) ? $this->parentRecord->ID : null),
+			// TODO Should be part of the form attribute, but not possible in current form API
+			$hintsField = new LiteralField('Hints', sprintf('<span class="hints" data-hints="%s"></span>', $this->SiteTreeHints())),
 			$parentField = new TreeDropdownField("ParentID", _t('CMSMain.AddFormParentLabel', 'Parent page'), 'SiteTree'),
 			new OptionsetField("PageType", "", $pageTypes, 'Page')
 		);
@@ -1312,6 +1314,7 @@ JS;
 		$this->extend('updatePageOptions', $fields);
 		
 		$form = new Form($this, "AddForm", $fields, $actions);
+		$form->addExtraClass('cms-add-form');
 		
 		return $form;
 	}
diff --git a/javascript/CMSMain.AddForm.js b/javascript/CMSMain.AddForm.js
index 1e636f30..765309ec 100644
--- a/javascript/CMSMain.AddForm.js
+++ b/javascript/CMSMain.AddForm.js
@@ -20,7 +20,57 @@
 				this._super();
 			},
 			onclick: function() {
-				this.parents('li:first').addClass('selected').siblings().removeClass('selected');
+				var el = this.parents('li:first');
+				el.setSelected(true);
+				el.siblings().setSelected(false);
+			}
+		});
+		
+		$(".cms-add-form").entwine({
+			onmatch: function() {
+				var self = this;
+				this.find('#ParentID .TreeDropdownField').bind('change', function() {
+					self.updateTypeList();
+				});
+			},
+			
+			/**
+			 * Limit page type selection based on parent class.
+			 * Similar implementation to LeftAndMain.Tree.js.
+			 */
+			updateTypeList: function() {
+				var hints = this.find('.hints').data('hints'), 
+					metadata = this.find('#ParentID .TreeDropdownField').data('metadata'),
+					id = this.find('#ParentID .TreeDropdownField').getValue(),
+					newClassName = metadata[0].ClassName,
+					disallowedChildren = hints[newClassName ? newClassName : 'Root'].disallowedChildren || [],
+					defaultChildClass = hints[newClassName ? newClassName : 'Root'].defaultChild || null;
+				
+				// Limit selection
+				this.find('#PageType li').each(function() {
+					var className = $(this).find('input').val(), isAllowed = ($.inArray(className, disallowedChildren) == -1);
+					$(this).setEnabled(isAllowed);
+				});
+				
+				// Set default child selection, or fall back to first available option
+				if(defaultChildClass) {
+					var selectedEl = this.find('#PageType li input[value=' + defaultChildClass + ']').parents('li:first');
+				} else {
+					var selectedEl = this.find('#PageType li:not(.disabled):first');
+				}
+				selectedEl.setSelected(true);
+				selectedEl.siblings().setSelected(false);
+			}
+		});
+		
+		$(".cms-add-form #PageType li").entwine({
+			setSelected: function(bool) {
+				this.toggleClass('selected', bool);
+				this.find('input').attr('checked', bool ? 'checked' : null);
+			},
+			setEnabled: function(bool) {
+				$(this).toggleClass('disabled', bool);
+				$(this).find('input').attr('disabled', bool ? '' : 'disabled');
 			}
 		});