Is there any way to stop the wp-container-{id} class from being output in the Group block?

[ddryo]

For classic themes that are not FSE themes, I don't think wp-container-{id} is necessary.

I would like to have the ability to turn off this class, as I feel this makes the HTML look messy.

On the other hand, as I wrote in #38126, I need a class that can determine that it is a "Row" block.

[MatzeKitt]

This should do the trick:

remove_filter( 'render_block', 'gutenberg_render_layout_support_flag' );

add_filter( 'render_block', function( $block_content, $block ) {
	if ( $block['blockName'] === 'core/group' ) {
		return $block_content;
	}
	
	return gutenberg_render_layout_support_flag( $block_content, $block );
}, 10, 2 );

This will remove the function that creates this class in the first place and then adds it again for every other block type.

[ddryo]

@MatzeKitt

Thank you. But that didn't work out.
I got an Call to undefined functiongutenberg_render_layout_support_flag() error.

[ddryo]

However, I was able to remove wp-container-{id} from all blocks with the following code.

remove_filter( 'render_block', 'wp_render_layout_support_flag', 10, 2 );
remove_filter( 'render_block', 'gutenberg_render_layout_support_flag', 10, 2 );

[nlstm-tm]

It took some digging but this is the proper way to do it specifically in the Gutenberg Editor

wp.hooks.removeFilter('editor.BlockListBlock', 'core/editor/layout/with-layout-styles')

Do this in your plain JS file enqueued in the Gutenberg Editor

[ddryo]

As it is used in various blocks, not just groups, I have found this specification necessary.

So I will close.

[jerome-toole]

In WordPress 6.1, a theme support option was added to opt out of these inlined layout styles and dynamic classes.

// Disable layout styles.

add_theme_support( 'disable-layout-styles' );

https://make.wordpress.org/core/2022/10/10/updated-editor-layout-support-in-6-1-after-refactor/

I found that the previous answer's solution (removing the wp_render_layout_support_flag filter) mostly worked but also removed some classes from the markup that I did want such as alignment classes (e.g. .is-content-justification-center).