To me, nothing can be more fun or more frustrating than learning something new that will make my website better. When I first heard of sitemap.xml files, I heard about them through the google webmaster pages. I don't know for sure if google started this or if it was something that came out of something else. My experience with the sitemap.xml file grew out of Google's Webmasters pages.
My first experience in creating a sitemap.xml file came from the java app from over at audit my pc dot-com. The application was an easy load and quickly generated me a sitemap.xml file that I could put in the root directory of davidj.org. I was so impressed with how quick I had a sitemap.xml file to submit that I gladly put a link to this page on the main page of my site.
There isn't much to the sitemap.xml file. There is the main container, the 'urlset' and then the url's within that set. Each URL consists of a location, a modified date, a priority rating, and a frequency of updates tag. The java app only filled in the location(http://www.davidj.org/index.html) and occassionally the modified date(2006-04-05 12:34:56). The priority is given as a drop down as well as the frequency of updates. At first I went through the 150 or so locations and really thought about how often I updated them. Then I found out that my sitemap.xml file was not working and the extra information wasn't helping.
The next place that I went that was helpful in working out the sitemap.xml problem was nodemap.com. I was having difficulty with google believing in my sitemap.xml file. Google kept telling me that my sitemap.xml file was empty and that there were no URL's in it. I got frustrated!
In order to use nodemap.com I had to set up an account, but it was relatively painless. Then I was able to go to my account and use their validator. They said the same thing that google said. I was more lost. (When I came back to this page later, with a working sitemap.xml file, I was very impressed!)
I kept searching for more information about what was wrong with my sitemap.xml file. All google was saying was that it was Empty. There seemed to be very little help against that Empty error message that would help me. I did, however, find another site to aid in my quest for a clean sitemap.xml file.
xml-sitemaps.com has an online tool for generating sitemap.xml files. It looks like they have written a php script that can be installed on a server to update the sitemap.xml files as well. However, I wanted to use their oneline sitemap.xml generator to see if there was a difference in the syntax that might explain my empty error from google. There is a limit of 500 url's in the online generator, and there were no excludes that I found so I was at their mercy for what they put in. Additionally, they generate urllist.txt files for yahoo. They also generate basic html for a sitemap if you just want to throw it on your website. This is a class act website if I ever saw one. But the file I put up still wasn't validating!
sitemapdoc dot-com may be a busy looking site, but they have got some serious good stuff going on here as well. There is a big button that says create map that will crawl a website and return a nice sitemap.xml file. They have a limit of 750 pages and have a button to show filtering and settings. You just have to look a little harder for what you need to find it here. But it is there.
The tool that I like is called the 'Edit Existing Map Sitemap Doctor' and is awesome for validating and updating a current sitemap.xml file. The interface again is a little rough, but I can handle rough because of the power! They have an excellent validator that directs you right to where you want to be to find errors.
I know what some of you are wondering, did you find the answer to the empty sitemap error from google? Yes, I did. I can tell you honestly that it had nothing to do with google or any of the validation engines. I was having my php get in the way of the xml file. I had to add a couple lines to the top of the xml file to get around php stomping on it. I am willing to bet that this is not a problem that many others will experience. I added these lines to the top of the sitemap file:
<? header('Content-type: text/xml'); ?>
<? print "<?xml version=\"1.0\" encoding=\"UTF-8\"?>";?>
I removed the <?xml version="1.0" encoding="UTF-8"?> at the top of the xml file. I must remember to do this! You should probably forget that you read it.
So now I am a happy sitemap.xml camper. I hope these links are a help to you as well.
These links were probably referenced above, but if you came here looking for them, this is the easiest way to go!