wscott: Added base code for a working Google Sitemaps support.

Changes in Files: 
* Sitemap.php - controller for the sitemap, new 
* Sitemap.ss - template for the sitemap, new 

* main.php - added director rule 
* SiteTree?.php - added 'priority' database field, cms code to override priority 

TODO: ping google when the sitemap is updated, 

namely when pages are added / removed, or when a priority is overridden 


git-svn-id: svn://svn.silverstripe.com/silverstripe/open/modules/sapphire/trunk@41689 467b73ca-7a2a-4603-9d3b-597d59a354a9

core/control/Sitemap.php

@@ -0,0 +1,80 @@
+<?php
+/**
+ * Initial implementation of Sitemap support.
+ * SitemapController should handle requests to 'sitemap.xml'
+ * the other two classes are used to render the sitemap
+ */
+
+class Sitemap extends Controller {
+	protected $Pages;
+	function __construct()
+	{
+		$this->Pages=DataObject::get('SiteTree');
+	}
+
+	public function Items()
+	{
+		foreach($this->Pages as $page)
+		{
+			// The one field that isn't easy to deal with in the template is
+			// Change frequency, so we set that here.
+			$properties = $page->toMap();
+			$created = new Datetime($properties['Created']);
+			$now = new Datetime();
+			$versions = $properties['Version'];
+			$timediff = $now->format('U') - $created->format('U');
+			
+			// Check how many revisions have been made over the lifetime of the
+			// Page for a rough estimate of it's changing frequency.
+			
+			$period = $timediff / ($versions + 1);
+			
+			if($period > 60*60*24*365) // > 1 year
+			{
+				$page->ChangeFreq='yearly';
+			}
+			else if($period > 60*60*24*30) // > ~1 month
+			{
+				$page->ChangeFreq='monthly';
+			}
+			else if($period > 60*60*24*7) // > 1 week
+			{
+				$page->ChangeFreq='weekly';
+			}
+			else if($period > 60*60*24) // > 1 day
+			{
+				$page->ChangeFreq='daily';
+			}
+			else if($period > 60*60) // > 1 hour
+			{
+				$page->ChangeFreq='hourly';
+			}
+			else // < 1 hour
+			{
+				$page->ChangeFreq='always';
+			}
+		}
+		return $this->Pages;
+	}
+	
+	static function Ping()
+	{
+		$location = urlencode(Director::absoluteBaseURL() . '/sitemap.xml');
+		
+		$response = HTTP::sendRequest("www.google.com", "/webmasters/sitemaps/ping",
+			"sitemap=" . $location);
+			
+		return $response;
+	}
+	
+	function index($url)
+	{
+		// We need to override the default content-type
+		ContentNegotiator::disable();
+		header('Content-type: application/xml; charset="utf-8"');
+		
+		// But we want to still render.
+		return array();
+	}
+}
+?>

core/model/SiteTree.php

@@ -671,7 +671,9 @@ class SiteTree extends DataObject {
 						new HeaderField("Search Engine Meta-tags"),
 						new TextField("MetaTitle", "Title"),
 						new TextareaField("MetaDescription", "Description"),
-						new TextareaField("MetaKeywords", "Keywords")
+						new TextareaField("MetaKeywords", "Keywords"),
+						new LiteralField("", "<p>Manually specify a Priority for this page:: (valid values are from 0 to 1)</p>"),
+						new NumericField("Priority","Page Priority")
 					)
 				),
 				new Tab("Behaviour",
@@ -990,7 +992,8 @@ class SiteTree extends DataObject {
 		"Viewers" => "Enum('Anyone, LoggedInUsers, OnlyTheseUsers', 'Anyone')", 
  		"Editors" => "Enum('LoggedInUsers, OnlyTheseUsers', 'LoggedInUsers')", 
  		"ViewersGroup" => "Int", 
- 		"EditorsGroup" => "Int" 
+ 		"EditorsGroup" => "Int",
+		"Priority" => "Float"
 	);
   
   static $indexes = array(
@@ -1028,7 +1031,8 @@ class SiteTree extends DataObject {
 		"Status" => "New page",
 		"CanCreateChildren" => array(10),
 		"Viewers" => "Anyone", 
- 		"Editors" => "LoggedInUsers" 
+ 		"Editors" => "LoggedInUsers",
+		"Priority" => .5
 	);
 
 	static $has_one = array(

main.php

@@ -63,6 +63,7 @@ Director::addRules(10, array(
 	'$Controller/$Action/$ID/$OtherID' => '*',
 	'images/$Action/$Class/$ID/$Field' => 'Image_Uploader',
 	'' => 'RootURLController',
+	'sitemap.xml' => 'Sitemap',
 ));
 
 Director::addRules(1, array(

templates/Sitemap.ss

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<urlset xmlns="http://www.google.com/schemas/sitemap/0.84"
+xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+xsi:schemaLocation="http://www.google.com/schemas/sitemap/0.84">
+	<% control Items %>
+	<url>
+		<loc>$AbsoluteLink</loc>
+		<lastmod>$LastEdited.Format(c)</lastmod>
+		<% if ChangeFreq %><changefreq>$ChangeFreq</changefreq><% end_if %>
+		<% if Priority %><priority>$Priority</priority><% end_if %>
+	</url>
+	<% end_control %>
+</urlset>