Sidebar-page.php issues

Well I got the error to go away, but still have the original problem of the sidebar dropping down below the main content

Here is the way it is supposed to look. This page uses sidebar-page.php as the template:

LINK

But here is how it ends up when I create a new template using sidebar-page.php. The sidebar drops below the main content:

LINK

Your primary content has a width of 100%, therefore it spans the entire website and doesn’t make room for the secondary content (sidebar).

Yes, but WordPress is supposed to adjust that when using the sidebar-page.php template. I made an exact copy of that file, changed the template name at the top, and saved it as a different file name. When I assign it as a template to a page, I don’t get the same layout as the sidebar.php template.

Nevermind, I finally got it, but I would love to know why this is so hard to do? Surely people have the need for multiple static pages with different sidebars? Seems this should be much more convenient to achieve!

https://codex.www.ads-software.com/Child_Themes#Using_functions.php

don’t copy functions.php of the parent theme into the chilc theme;

as for the sidebar page template, you need to add a filter function for the body_class into functions.php of the child theme, to remove the .singular class when using the sidebar page template;

example:

add_filter('body_class', 'adjust_body_class_for_template', 20, 2);
function adjust_body_class_for_template($wp_classes, $extra_classes) { 

if( is_page_template('yoursidebarpagetemplatefilename.php') ) :
// Filter the body classes     

          foreach($wp_classes as $key => $value) {
          if ($value == 'singular') unset($wp_classes[$key]);
          }

endif;
// Add the extra classes back untouched
return array_merge($wp_classes, (array) $extra_classes );
}

EDIT PS:
well done.

I would love to know why this is so hard to do?

it just is – ‘hard’ or ‘not hard’ depends on personal experience with WordPress; Twenty Eleven is just a bit tricky in some aspects.

Thanks. Yes, seems quite a bit more complex than twenty ten..