Dynamically Overriding a Page’s Template

It is easy to override the template for a post or page in WordPress in a few ways. For example, the naming of page template files can be used to override a single page’s template:

• page-{id}.php
• page-{slug}.php

Or, a page template can be chosen in the Page Attributes section when editing a page:

This works great when you always want a page template to be used for a particular page. But what if you need to change a page’s template based on something that might change? Like the current user’s role, for example? Well, you can use the template_include filter in WordPress to override the normally-used template in a function.

Start out by attaching a function to the filter:

add_filter( 'template_include', 'dynamic_page_template' );

This can be added to your theme’s functions.php file or to a custom plug-in. In this example, the function called dynamic_page_template will be invoked. This function will accept the parameter, $page_template, which is the $page_template that is to be used. If you want the page template defined in a way above (by the template name or the selected template in the Page Attribute area) to work as normal, simply returning $page_template will accomplish this. However, we can also set $page_template to something different and return that instead. Here is a simple example:

function dynamic_page_template( $page_template ){
  global $post;
  if (100 == $post->ID) :
    $page_template = get_template_directory() . "/page-test.php";
  endif;
  return $page_template;
}

In this example, we are pulling in the $post (or page) information by calling it globally. Then, we can check for the post ID value. If the ID is 100, we are setting the page template dynamically to the page-test.php file in our theme. The get_template_directory call gets us the directory for our theme. Now, even if we have a file named page-100.php, our function will take precedence.