In a new post to his blog Benjamin Schneider looks at how you can use the Tidy extension to clean up the (X)HTML markup that comes out of your application.

Tidy is a very cool PHP extension. You can let it tell you what kind of mistakes you might have in your HTML markup and even correct it for you - if you want. In my projects I use it to give me a hint if my generated markup is invalid. This way I can easily correct it during development without being dependent on external validators. In this post I will show you how easy it is and how few lines of code you need to make your application show any potential errors you might have in your HTML markup.

He shows how, with the help of output buffering, to grab the HTML output of your script and push it through the Tidy functionality (via a call to tidy_parse_string) and outputting the results. It even has a built in error catcher for when it finds invalid formatting in the generated markup. You can find out more about the features of this extension in the PHP manual.