Change record status: 
Project: 
Introduced in branch: 
8.x
Introduced in version: 
8.0
Description: 

In Drupal 7 it was possible to specify separate block templates per region, such as block--header.tpl.php and block--footer.php to output different HTML for blocks placed in the header and footer regions. It was also possible to adjust variables based on region in hook_preprocess_block(). Both of these features have been removed.

It is suggested you use standard CSS cascading selectors to style blocks differently on different parts of the page.

Impacts: 
Themers
Updates Done (doc team, etc.)
Online documentation: 
Not done
Theming guide: 
Not done
Module developer documentation: 
Not done
Examples project: 
Not done
Coder Review: 
Not done
Coder Upgrade: 
Not done
Other: 
Other updates done

Comments

Benia’s picture

If I use CSS to hide #sidebar, in whatever theme, a wide blank block is created instead; The sidebar region keeps staying, but just as an empty and blank "box".

allan00958’s picture

I don't know if you found the answer already but maybe try this in your page.html.twig:

<div class="someClass">
    <div class="row">
        {% if page.sidebar %}
            <div class="col-12">
               {{ page.sidebar}}
            </div>   
        {% endif %}
    </div>
</div>

Maybe add an if statement and hide the sidebar using a preprocess function.