Posted by stpaultim on Fri, Jun 28, 2024 - 1:30pm --- Updated: Aug 17 '24 - 12:32am

What would be the best way for a module to insert a class into the body tag for all pages on a site?

I tried overriding the core page.tpl.php template in my module, but that caused an unrecoverable error. I had to tear the site down and rebuild it (it was a demo site). 

Maybe I did that wrong? Any thoughts?

EDIT (August 16, 2024):

My use case for this is pretty specific and niche. I've created the Digital Agency Recipe Package, which creates a bunch of specific functionality and content in the way that a distribution might. I would like to provide a body class on all pages, when this recipe/module is active. It's my theory, that this will make it easier for another contributed theme to support this recipe. If there is a class specific to this recipe, other contributed themes can make modifications for this recipe without fear of breaking existing sites. 

 

Comments

Fri, Jun 28, 2024 - 3:13pm by argiepiano

As usual with template files, the best way to add a class anywhere is to implement template_preprocess_page(&$variables) {} in your theme's template.php file (replace template_preprocess_page with YOUR_THEME_preprocess_page).

Then you simply do

$variables['classes'][] = 'my-new-class';

Sat, Jun 29, 2024 - 11:46pm by amilenkov

I don't understand what is the need to have a body CSS class that is active on ALL pages on the site? If it's for every URL, then why you can't use CSS rules using the body tag itself as a selector.

But I've been trying to find a way for a long time and I would be very grateful if someone could tell me how to put a body class on certain categories of pages, for example:

  • Path - a class to be active only for a given page or more specifically NID (for nodes), TID (for tags) and UID (for users)
  • Content type - for all nodes of a specific content type
  • User Role
  • Random

Such a module existed for Drupal 6 and was extremely useful:
https://www.drupal.org/project/themer

The solution proposed by argiepiano can also be used - via template.php and not via a separate module, as long as if it is possible to code that generates a class differentiated at least for a specific NID TID or UID or just Random code for each page, layout or view

Sat, Aug 17, 2024 - 1:28am by stpaultim

I was able to use the hint by @argiepiano in the .module file for my module. The code was this simple:

If you want to only add the class for a specific content type, wrap it in an "if" statement and check for whatever conditions you need.

function digital_agency_preprocess_page(&$variables) { 
  $variables['classes'][] = 'digital-agency';
 }

Sat, Jun 29, 2024 - 11:57pm by amilenkov

Currently, Backdrop sets the body class only if the page is front page, class is "front",  also for the content type - "node-type-page". It would be useful to have more additional classes depending on the specific content or View

 

Sun, Aug 25, 2024 - 5:31am by DanM

I've accomplished something similar by using a Paragraphs type with a class applied to it.

Tue, Nov 12, 2024 - 6:56am by Enthusiast

In page.tpl.php you can get the current path and add it to the class array
$classes[] = 'path-' . str_replace('/', '', $_SERVER['REQUEST_URI']);
You will get an original class for each page. Sometimes it helps.

Wed, Nov 13, 2024 - 12:45am by amilenkov

@Enthusiast
Thanks so much for this tip!