<?php
/**
* Background block support flag.
*
* @package WordPress
* @since 6.4.0
*/
/**
* Registers the style block attribute for block types that support it.
*
* @since 6.4.0
* @access private
*
* @param WP_Block_Type $block_type Block Type.
*/
function wp_register_background_support( $block_type ) {
// Setup attributes and styles within that if needed.
if ( ! $block_type->attributes ) {
$block_type->attributes = array();
}
// Check for existing style attribute definition e.g. from block.json.
if ( array_key_exists( 'style', $block_type->attributes ) ) {
return;
}
$has_background_support = block_has_support( $block_type, array( 'background' ), false );
if ( $has_background_support ) {
$block_type->attributes['style'] = array(
'type' => 'object',
);
}
}
/**
* Renders the background styles to the block wrapper.
* This block support uses the `render_block` hook to ensure that
* it is also applied to non-server-rendered blocks.
*
* @since 6.4.0
* @since 6.5.0 Added support for `backgroundPosition` and `backgroundRepeat` output.
* @access private
*
* @param string $block_content Rendered block content.
* @param array $block Block object.
* @return string Filtered block content.
*/
function wp_render_background_support( $block_content, $block ) {
$block_type = WP_Block_Type_Registry::get_instance()->get_registered( $block['blockName'] );
$block_attributes = ( isset( $block['attrs'] ) && is_array( $block['attrs'] ) ) ? $block['attrs'] : array();
$has_background_image_support = block_has_support( $block_type, array( 'background', 'backgroundImage' ), false );
if (
! $has_background_image_support ||
wp_should_skip_block_supports_serialization( $block_type, 'background', 'backgroundImage' )
) {
return $block_content;
}
$background_image_source = isset( $block_attributes['style']['background']['backgroundImage']['source'] )
? $block_attributes['style']['background']['backgroundImage']['source']
: null;
$background_image_url = isset( $block_attributes['style']['background']['backgroundImage']['url'] )
? $block_attributes['style']['background']['backgroundImage']['url']
: null;
if ( ! $background_image_source && ! $background_image_url ) {
return $block_content;
}
$background_size = isset( $block_attributes['style']['background']['backgroundSize'] )
? $block_attributes['style']['background']['backgroundSize']
: 'cover';
$background_position = isset( $block_attributes['style']['background']['backgroundPosition'] )
? $block_attributes['style']['background']['backgroundPosition']
: null;
$background_repeat = isset( $block_attributes['style']['background']['backgroundRepeat'] )
? $block_attributes['style']['background']['backgroundRepeat']
: null;
$background_block_styles = array();
if (
'file' === $background_image_source &&
$background_image_url
) {
// Set file based background URL.
$background_block_styles['backgroundImage']['url'] = $background_image_url;
// Only output the background size and repeat when an image url is set.
$background_block_styles['backgroundSize'] = $background_size;
$background_block_styles['backgroundRepeat'] = $background_repeat;
$background_block_styles['backgroundPosition'] = $background_position;
// If the background size is set to `contain` and no position is set, set the position to `center`.
if ( 'contain' === $background_size && ! isset( $background_position ) ) {
$background_block_styles['backgroundPosition'] = 'center';
}
}
$styles = wp_style_engine_get_styles( array( 'background' => $background_block_styles ) );
if ( ! empty( $styles['css'] ) ) {
// Inject background styles to the first element, presuming it's the wrapper, if it exists.
$tags = new WP_HTML_Tag_Processor( $block_content );
if ( $tags->next_tag() ) {
$existing_style = $tags->get_attribute( 'style' );
$updated_style = '';
if ( ! empty( $existing_style ) ) {
$updated_style = $existing_style;
if ( ! str_ends_with( $existing_style, ';' ) ) {
$updated_style .= ';';
}
}
$updated_style .= $styles['css'];
$tags->set_attribute( 'style', $updated_style );
$tags->add_class( 'has-background' );
}
return $tags->get_updated_html();
}
return $block_content;
}
// Register the block support.
WP_Block_Supports::get_instance()->register(
'background',
array(
'register_attribute' => 'wp_register_background_support',
)
);
add_filter( 'render_block', 'wp_render_background_support', 10, 2 );