wp-includes/script-loader.php:3684Adds hooks to load block styles on demand in classic themes.
function wp_load_classic_theme_block_styles_on_demand(): void { // This is not relevant to block themes, as they are opted in to loading separate styles on demand via _add_default_theme_supports(). if ( wp_is_block_theme() ) { return; } /* * Make sure that wp_should_output_buffer_template_for_enhancement() returns true even if there aren't any * `wp_template_enhancement_output_buffer` filters added, but do so at priority zero so that applications which * wish to stream responses can more easily turn this off. */ add_filter( 'wp_should_output_buffer_template_for_enhancement', '__return_true', 0 ); // If a site has opted out of the template enhancement output buffer, then bail. if ( ! wp_should_output_buffer_template_for_enhancement() ) { return; } // The following two filters are added by default for block themes in _add_default_theme_supports(). /* * Load separate block styles so that the large block-library stylesheet is not enqueued unconditionally, and so * that block-specific styles will only be enqueued when they are used on the page. A priority of zero allows for * this to be easily overridden by themes which wish to opt out. If a site has explicitly opted out of loading * separate block styles, then abort. */ add_filter( 'should_load_separate_core_block_assets', '__return_true', 0 ); if ( ! wp_should_load_separate_core_block_assets() ) { return; } /* * Also ensure that block assets are loaded on demand (although the default value is from should_load_separate_core_block_assets). * As above, a priority of zero allows for this to be easily overridden by themes which wish to opt out. If a site * has explicitly opted out of loading block styles on demand, then abort. */ add_filter( 'should_load_block_assets_on_demand', '__return_true', 0 ); if ( ! wp_should_load_block_assets_on_demand() ) { return; } // Add hooks which require the presence of the output buffer. Ideally the above two filters could be added here, but they run too early. add_action( 'wp_template_enhancement_output_buffer_started', 'wp_hoist_late_printed_styles' );}Introduced in 6.9.0. Unchanged from 6.9.7 through 7.1.0.
Signature, return type and hooks compared across 3 parsed releases.
src/wp-includes/script-loader.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.