Adding the sidebar to a Twentyeleven child theme

Twentyeleven offers a lot of cool features, one of my favorites is the Showcase template. However one of the downsides in my opinion (and probably yours, if you’ve found this article) is lack of a sidebar on your single posts and pages.

Others have pointed out viable solutions, however I wanted to stick to best practices and keep my parent theme unmodified.

Here I will explore how to add the sidebar to a twentyeleven child theme in only half a dozen lines of code.

Note: More information on creating a child theme can be found here.

We’ll begin by adding the sidebar back to your posts, by copying single.php to our child theme and modifying it.

            </div><!-- #content -->
        </div><!-- #primary -->

<?php get_footer(); ?>

Add the get_sidebar() function directly above get_footer() like so

            </div><!-- #content -->
        </div><!-- #primary -->

<?php get_sidebar(); ?>
<?php get_footer(); ?>

The same can be done for page.php if you want the sidebar to appear on your pages as well.

Now, the other tutorials I’ve seen advise you to edit twentyeleven’s functions.php and comment out the remove_twentyeleven_body_classes() function and it’s accompanying add_action(). You can certainly do so, but it goes against best practices, and you risk losing your modifications if you update twentyeleven.

In your child theme, create or modify your functions.php to contain the following.

<?php
function remove_twentyeleven_body_classes() {
    remove_filter( 'body_class', 'twentyeleven_body_classes' );
}
add_action( 'after_setup_theme', 'remove_twentyeleven_body_classes' );
?>

Here we are removing the filter that is added in twentyeleven’s functions.php, but since the child theme’s files are processed prior to the parents, simply removing the filter is not adequate and would be overridden by the parent function. As a result we need to add an action to remove the filter during the after_setup_theme action.

Save your files, and assuming it wasn’t already, activate the theme.
That’s it. Now you have your sidebar.