By default all Wordpress posts viewed as a single post are controlled by the particular theme’s “single.php” file.

Wordpress, by default is setup to use one template file (“single.php“) for every post.(But what if you wanted to display a different layout or different code dependent on the specific categories a post or filed into?

To do this with Wordpress; one needs to use a bit of PHP in the “single.php” file and create category specific files.

In the below example lets assume the following:

• Category 2 is my Blog
• Category 15 is a Photography section
• Category 18 is a Video section

I want to display a different layout according to the particular post’s category so I would edit “single.php” as follows:

<?php
$post = $wp_query->post;
if ( in_category('2') ) {
include(TEMPLATEPATH . '/single-blog.php'); } 
elseif ( in_category('15') ) {
include(TEMPLATEPATH . '/single-photography.php'); } 
elseif ( in_category('18') ) {
include(TEMPLATEPATH . '/single-video.php'); } 
else {
include(TEMPLATEPATH . '/single-default.php');
}
?>

Proceeding editing this, the referenced files must be created e.g. “single-blog.php“, “single-photography.php” and “single-video.php” file referenced above. Also a “single-default.php” file should also be created so that any post that is not in any of the specified categories (15, 18 ir 2) will just use a default template file – “single-default.php“.