API Remove Trackback support

It was disabled since migrating the module to SS3,
and the whole concept has become less relevant since spammers discovered trackbacks
(ref http://en.wikipedia.org/wiki/Trackback#Spam).

Since we don't have the resources to make a spam-proof trackback system,
its prudent to remove it instead.

code/BlogEntry.php

@@ -37,10 +37,6 @@ class BlogEntry extends Page {
 		'ShowInMenus' => false
 	);
 
-	private static $extensions = array(
-		'TrackBackDecorator'
-	);
-
 	/**
 	 * Is WYSIWYG editing allowed?
 	 * @var boolean
@@ -174,21 +170,6 @@ function EditURL() {
 		return ($this->getParent()) ? $this->getParent()->Link('post') . '/' . $this->ID . '/' : false;
 	}
 
-	/**
-	 * Check to see if trackbacks are enabled.
-	 */
-	function TrackBacksEnabled() {
-		return ($this->getParent()) ? $this->getParent()->TrackBacksEnabled : false;
-	}
-
-	function trackbackping() {
-		if($this->TrackBacksEnabled() && $this->hasExtension('TrackBackDecorator')) {
-			return $this->decoratedTrackbackping();
-		} else {
-			Controller::curr()->redirect($this->Link());
-		}
-	}
-
 	function IsOwner() {
 		if(method_exists($this->Parent(), 'IsOwner')) {
 			return $this->Parent()->IsOwner();
@@ -251,7 +232,6 @@ class BlogEntry_Controller extends Page_Controller {
 
 	private static $allowed_actions = array(
 		'index',
-		'trackbackping',
 		'unpublishPost',
 		'PageComments',
 		'SearchForm'

code/BlogHolder.php

@@ -14,15 +14,14 @@
 class BlogHolder extends BlogTree implements PermissionProvider {
 
 	private static $icon = "blog/images/blogholder-file.png";
-
+	
 	private static $description = "Displays listings of blog entries";
 
 	private static $singular_name = 'Blog Holder Page';
-	
+
 	private static $plural_name = 'Blog Holder Pages';
 
 	private static $db = array(
-		'TrackBacksEnabled' => 'Boolean',
 		'AllowCustomAuthors' => 'Boolean',
 		'ShowFullEntry' => 'Boolean', 
 	);
@@ -42,13 +41,13 @@ function getCMSFields() {
 		$fields = parent::getCMSFields();
 		SiteTree::enableCMSFieldsExtensions();
 
-		//sets the ID and Name Map for Blog Ownership
-		$owners = new DropdownField('OwnerID', 'Blog owner', $blogOwners->map('ID', 'Name')->toArray());
-		$owners->setEmptyString('(None)');
-		$owners->setHasEmptyDefault(true);
-
-		$fields->addFieldToTab('Root.Main', new CheckboxField('TrackBacksEnabled', 'Enable TrackBacks'), "Content");
-		$fields->addFieldToTab('Root.Main', $owners, "Content");
+		$fields->addFieldToTab(
+			'Root.Main', 
+			DropdownField::create('OwnerID', 'Blog owner', $blogOwners->map('ID', 'Name')->toArray())
+				->setEmptyString('(None)')
+				->setHasEmptyDefault(true),
+			"Content"
+		);
 		$fields->addFieldToTab('Root.Main', new CheckboxField('AllowCustomAuthors', 'Allow non-admins to have a custom author field'), "Content");
 		$fields->addFieldToTab("Root.Main", new CheckboxField("ShowFullEntry", "Show Full Entry"), "Content");
 

templates/Layout/BlogEntry.ss

@@ -18,8 +18,5 @@
 
 	<% if IsOwner %><p class="edit-post"><a href="$EditURL" id="editpost" title="<% _t('EDITTHIS', 'Edit this post') %>"><% _t('EDITTHIS', 'Edit this post') %></a> | <a href="$Link(unpublishPost)" id="unpublishpost"><% _t('UNPUBLISHTHIS', 'Unpublish this post') %></a></p><% end_if %>
 
-	<% if TrackBacksEnabled %>
-		<% include TrackBacks %>
-	<% end_if %>
 	$PageComments
 </div>