Themes: Add a shim for wp_body_open()

[pento]

Split off from #12563.

WordPress 5.2 adds the wp_body_open() function, and the default themes make use of it.

They don't have a shim for this function, however, so will trigger fatal errors if they're run on an older version of WordPress.

[lgedeon]

Proposed solution to add this to each of the default themes.

<?php
if ( ! function_exists( 'wp_body_open' ) ) {
        function wp_body_open() {
                do_action( 'wp_body_open' );
        }
}

We might also add the doc block. Not sure on expectations there.

[johnbillion]

What's the real purpose of the wp_body_open() wrapper function? It presents consistency with other functions such as wp_head() and wp_footer(), but would placing a direct call to do_action( 'wp_body_open' ) be so bad?

[timph]

Replying to johnbillion:

What's the real purpose of the wp_body_open() wrapper function? It presents consistency with other functions such as wp_head() and wp_footer(), but would placing a direct call to do_action( 'wp_body_open' ) be so bad?

I understand the consistency part, and agree with this. Just adding that do_action( 'wp_body_open' ) is 100% more clear about what it actually does as well. It's frustrating when you have to search through code just to figure out something is only a wrapper around an action.

[klihelp]

Core functions looks consistent in the theme, and without any parameter. Needed action:)

wp_head();

wp_body_open();

wp_footer();

[adamsilverstein]

What's the real purpose of the wp_body_open() wrapper function?

Mainly this was added this way for consistency with other function calls/existing pattern for header/footer calls. It was discussed a bit in #12563. I do see how switching to triggering an action directly would remove the need for a shim though, which we didn;t consider previously.

[ramiy]

The default themes, and any other theme should use:

<?php if ( function_exists( 'wp_body_open' ) ) wp_body_open(); ?>

instead of just:

<?php wp_body_open(); ?>

Unless the theme "Minimum Required WordPress Version" is 5.2+.

[ramiy]

The second patch implements the solution suggested by @lgedeon.

Note that some themes has a separate file with backward compatibility functions (inc/back-compat.php). In other themes the code implemented in functions.php.

[adamsilverstein]

Thanks for the patches @ramiy! I like 46679-back-comp.patch​ - it brings the functionality wherever these themes are used, benefiting users.

Does this look good to you @pento?

[pento]

Yah, I like the direction of 46679-back-comp.patch​. The function shouldn't go in inc/back-compat.php, though, as that file is only loaded on versions of WordPress where the theme won't work, and it'll prevent the theme from being activated. Where the file exists, lets put it in inc/template-tags.php.

To address the other options:

• I think the wp_body_open() function call fits better with the wp_head() / wp_footer() pattern. Particularly as this is the actual function call that works in WP 5.2+, using a do_action() call solely for back compat is presenting a sub-optimal example for folks to base their themes off.
• Adding a function_exists( 'wp_body_open' ) check is an unnecessary logic check in a template file, which should be avoided where possible.

[ramiy]

@pento Thanks for the feedback. I've updated the patch.

In 2010-2014 I used the functions.php file, In 2015-2019 I used the inc/template-tags.php file.

Also, I replaced if () { ... } with if () : ... endif;, to match the current code convention in theme files.

[ramiy]

@adamsilverstein @pento please review the new patch.

[adamsilverstein]

Thanks @ramiy - patch looks good to me. @pento - does this look good for commit?

[ramiy]

@pento ?

[pento]

Thanks, @ramiy! Patch looks good.

[adamsilverstein]

In 45256:

Bundled Theme: add a wp_body_open shim for older WordPress versions.

WordPress 5.2 adds the wp_body_open() function, and the default themes make use of it. This patch adds a shim for wp_body_open to bundled themes so this function will also work in older versions of WordPress.

Props lgedeon, johnbillion, timph, ramiy, pento.
Fixes #46679.