How to use ISAPI_Rewrite 3 with SilverStripe

Introduction

SilverStripe is an open source content management system and framework. It supports SE-friendly URLs but for Apache Web Server only. In this short article we will show how to use this feature with ISAPI_Rewrite under IIS.
In this article we suppose you already have IIS and ISAPI_Rewrite 3 installed. To write the article we used ISAPI_Rewrite 3.1.0.56 and SilverStripe 2.2.2.

Getting and Installing SilverStripe

You can download SilverStripe from this page: http://www.silverstripe.com/silverstripe-web-application-framework/. After downloading please install CMS according to installation instructions provided by vendor.

Enabling SE-friendly URLs

Actually, SE-friendly feature is enabled by default. But SilverStripe does not originally support IIS and ISAPI_Rewrite. On the first page of the installation you may see this text:

Picture 1. Information messages in the installation.

If you open your web-site after SilverStripe installation, you will see the note that mod_rewrite is not enabled. Actually, SilverStripe tries to find mod_rewrite (only), and if the search is successful, SilverStripe automatically creates rules in .htaccess file, and you get CMS working with SE-friendly URLs!

Thus under IIS we need to do some hacking. Let's just disable the check for mod_rewrite.
Please go to SilverStripe installation folder and open rewritetest.php file. Please find this code:

$testrewriting = file_get_contents($location);

if($testrewriting == 'OK') {
  return true;
}

And comment is out as follows:

//$testrewriting = file_get_contents($location);

//if($testrewriting == 'OK') {
	return true;
//}

So we just commented the check and left only return true and .htaccess configuration file required to run SEF URLs is already in place.
Done! Now you can use SilverStripe with pretty SE-friendly URLs powered by ISAPI_Rewrite.