HTTP Status Codes Are Important!!

So I was pushing some files over to our staging environment so that I could run some initial load testing on a project I've been working on, and my rsync script was missing a file. So when I hit the staging area, I received the Missing Template Error Handler that I specified in the ColdFusion Administrator. Great. However, I also happened to have the LiveHTTPHeaders Firefox plugin open because I was checking some HTTP header information a few minutes earlier. In checking the header information for the response, I noticed that a status of "200 OK" was being returned rather than the expected "404 Not Found" status. That's not good. I checked the LiveDocs page for the Missing Template Error Handler setting, and I didn't see any indication as to what the expected status code should be. I had just assumed that since ColdFusion was "smart" enough to know the page was missing, that it would set the 404 status code for me. Apparently not.

The HTTP status code of a request is important, particularly for web crawlers like Google or Yahoo! indexing your site. If you get rid of some files (and don't do anything at the IIS or Apache level to redirect users), then you're effectively telling the crawlers that the page still exists with the 200 OK status code.

The fix to the page was easy. Just drop this at the top of your Missing Template Error Handler template:

Note: It's critical that the statustext attribute say "Not Found" and nothing else.

A verification with my handy LiveHTTPHeaders plugin showed that the status code was indeed changed to 404 Not Found.

However, a missing template isn't the only situation where a status code is important. If you move a bunch of files around to better organize your site, keep in mind that search engines have likely already indexed your site or visitors may have bookmarked its location. Since you don't want to generate a bunch of missing template exceptions (regardless of the status code), a cleaner solution (again, barring directives being set in your web server configuration file) would be to specify a status code of 301, which notes that the requested file has been moved permanently. I've seen a lot of code where the developer has just used cflocation to do this. However, cflocation is notably different from a 301 redirect. A cflocation generates a 302 status code, which means that the file has been moved temporarily to a different URL. Hence, search engines will keep the "old" page in its index. However, with this code snippet below at the top of the old page, you can both redirect the user while specifying the more appropriate 301 error code:

For a list of HTTP status codes and their definitions, I highly recommend you bookmark this page (or del.icio.us it or whatever the kids are doing these days).

And remember, the cfheader tag is your friend in these situations.