i would like to have the following situation: some posts(that are assigned to a certain category) to show up in single.php when in single post view and the others i want them to show in index.php.
So i need to define/change what template wordpress is using dinamically. I guess that some query variable holds the name of the template file it should use if a certain condition is met. Example: some query variable is set to single.php for posts in single view if single.php is detected in the theme and to index.php if there's no single.php.
I want to know what variable is that and set it to a different value (file name) for a certain condition but i don't know if my info is right and if that's even possible.
I would like all posts from category "no sidebar custom header" to be displayed by single.php and all the rest by index.php.
Can i do that?