Last year I noticed that there were 11 ways to get to my blog. Literally 11 different URLs and it wasn't helping me my ranking in the search engines. I wrote about this in detail and how I used ISAPI_Rewrite to fix it up.
Fast forward to this year and the IIS7 team has been taking advantage of IIS7's modular design to release a bunch of new modules out-of-band.
Both the newest ISAPI_Rewrite and Apache's standard mod_rewrite module uses distributed configuration files or .htaccess files.
Here's just part of my .htaccess file that makes sure that all the incoming URLs end up at the final canonical http://www.hanselman.com/blog/
RewriteRule /blog/default\.aspx http\://www.hanselman.com/blog/ [I,RP]
RewriteCond Host: ^hanselman\.com
RewriteRule (.*) http\://www.hanselman.com$1 [I,RP]
RewriteCond Host: ^computerzen\.com
RewriteRule (.*) http\://www.hanselman.com$1 [I,RP]
RewriteCond Host: ^www.computerzen\.com
RewriteRule (.*) http\://www.hanselman.com/blog/ [I,RP]
After you've installed the IIS7 Rewrite module, you can bring rules in a couple ways. The nicest is by importing them directly. Notice the tree view in the screenshot below. It gets updated in as you type.
Note that the importer only really understands rules in the mod_rewrite syntax. It doesn't fully support ISAPI_Rewrite so some things like Host: and [I] aren't supported in this release, but I'm hoping (and I've formally asked) that they'll support them for the final RTW (Release to Web). If you have ISAPI_Rewrite rules, you can either convert them then manually edit them to tidy up (what I did), or you can convert them to mod_rewrite syntax first.
For example, in the rule importer UI I could have replaced the ISAPI_Rewrite directive "Host:" with "%{HTTP_HOST}" and "[I]" with "[NC]" (meaning case insensitive). Or, I can just edit the incorrectly imported rules.
This is useful for importing existing rules like mine, but it's still hard since we're talking obscure formats left and right. There's also an Add Rule wizard:
_thumb.png "Add rule(s)")
It's REALLY easy with the User Friendly URL dialog to interactively create mappings between the URLs your app uses and the URLs you want. See in the screenshot below how the combo-box is dynamically populated based on the example I put in the top text box?
_thumb.png "Add rules to enable user friendly URLs (2)")
The User Interface for this module is surprisingly deep in functionality. There's a Regular Expression tester built into it, which makes Regular Expressions suck by about -2.
ASP.NET MVC and SEO
I noticed a post by Jason Young recently on ASP.NET and SEO (Search Engine Optimization). He's concerned about trailing slashes
Ultimately I don't think it's that big of a deal since the URLs that your application generates are always consistent. Your app is what teaches search engines what to ask for. As long as your application is generating URLs that look the way you want them, you're cool.
The only real problem happens when other humans link to you and they make a mistake. Perhaps they include a trailing slash when you don't want one. Still, not a huge deal, but if you feel strongly about it, that's where a rewrite module comes in useful. I think that the Rewrite module would fit Jason's requirements.
Matt Hawley at eXcentrics World wrote a Legacy Route using ASP.NET Routing which is a clever idea as well. He could have certainly used this Rewrite Module, but ultimately as long as you're returning HTTP 301's (redirect permanent) or HTTP 302 (temporary redirect) as you fine appropriate, then use what makes you happy.
What's really important is that both these guys respect the permalink. A 404 is never a good thing.
Every site is different, but if I add a basic rule like this to my ASP.NET MVC site…
…and request http://localhost/rewritetest/Home/Index, the resulting HTTP Headers look like this, as the module forces the trailing backslash (of course you could also force NO backslash if it makes you happy):
GET /rewritetest/Home/Index HTTP/1.1
Accept-Encoding: gzip, deflate
Host: localhost
Connection: Keep-Alive
HTTP/1.1 301 Moved Permanently
Content-Type: text/html; charset=UTF-8
Location: http://localhost/rewritetest/Home/Index/
Server: Microsoft-IIS/7.0
X-Powered-By: ASP.NET
I'm not a regular expression expert, but searching the web for "mod_rewrite" rules will keep you busy for next 50 years. Here my favorite reference for .htaccess and mod_rewrite rules.
Learning the basics of the IIS7 Rewrite Module:
Functionality reference
Video walkthrough
Enjoy.
Hosting By
_2.png "Add rule(s)")
_2.png "Add rules to enable user friendly URLs (2)")
Ok, it's meme time. Now, you may be surprised to hear that under my cool exterior, I was a nerd in school. No, no, you say! It's not so! Surely you were the most popular kid, Scott? You weren't beaten brutally each day for having glasses that weighed more than your huge head? Nonsense!
