mukeshpanchal27 · October 1, 2024 09:48 · felixarntz · Sep 25, 2024 · mukeshpanchal27 · Sep 26, 2024
diff --git a/README.md b/README.md
diff --git a/wpp-column-context.php b/wpp-column-context.php
 <?php
 /**
 * Plugin Name: WPP Column Context
 * Version: 0.1
 * Author: Mukesh Panchal
 * License: GPL2
 */

 namespace WPP_Column_Context;

 use WP_HTML_Tag_Processor;

 // If this file is called directly, abort.
 if ( ! defined( 'WPINC' ) ) {
 	die;
 }

 add_filter(
 	'render_block_context',
 	function( $context, $block, $parent ) {
 		// Merge current context into the parent's context.
 		if ( $parent ) {
 			$context = array_merge( $parent->context, $context );
 		}

 		if ( 'core/columns' === $block['blockName'] ) {
 			$context['wpp-columns'] = count( $block['innerBlocks'] );
 			// Extra context for testing.
 			$context['wpp-columns-extra'] = 'columns-extra';
 		}

 		// For demo purposes, this assumes all unspecified columns are equal widths
 		if ( 'core/column' === $block['blockName'] ) {
 			$context['wpp-col-width'] = $block['attrs']['width'] ?? 'auto';
 			// Extra context for testing.
 			$context['wpp-col-extra'] = 'col-extra';
 		}
 		return $context;
 	},
 	10,
 	3
 );

 /*
 * Inspiration taken from current block binding implementation.
 * https://github.com/WordPress/wordpress-develop/blob/6.6/src/wp-includes/class-wp-block-bindings-registry.php#L193-L204
 */
 add_filter(
 	'get_block_type_uses_context',
 	function ( $uses_context, $block_type ) {
 		if ( 'core/image' === $block_type->name ) {
 			// Use array_values to reset the array keys.
 			return array_values( array_unique( array_merge( $uses_context, array( 'wpp-columns','wpp-col-width' ) ) ) );
 		}
 		return $uses_context;
 	},
 	10,
 	2
 );

 add_filter( 'render_block_core/image', __NAMESPACE__ . '\\wpp_add_image_block_sizes', 10, 3 );
 /**
 * Calculate image sizes attribute for an image block during rendering.
 *
 * @param string   $block_content The block content.
 * @param array    $parsed_block  The parsed block data.
 * @param WP_Block $wp_block      The block instance.
 * @return string The updated block content.
 */
 function wpp_add_image_block_sizes( $block_content, $parsed_block, $wp_block ) {

 	// If you want to check the context for image block add `?debug` in you url.
 	if ( isset( $_GET['debug'] ) ) {
 		echo '<pre>';
 		print_r( $wp_block->context );
 		echo '</pre>';
 	}
 	/**
 	 * Callback for calculating image sizes attribute value for an image block.
 	 *
 	 * This is a workaround to use block context data when calculating the img sizes attribute.
 	 *
 	 * @since 😎
 	 *
 	 * @param string $sizes The image sizes attribute value.
 	 * @param array  $size  The image size data.
 	 */
 	$filter = function( $sizes, $size ) use ( $wp_block ) {
 		$alignment    = $wp_block->attributes['align'] ?? '';
 		$columns      = $wp_block->context['wpp-columns'] ?? ''; // Consider two columns
 		$column_width = $wp_block->context['wpp-col-width'] ?? ''; // Consider 50% each width

 		// Hypotehtical function to calculate better sizes.
 		$sizes = wpp_better_sizes_calc( $size, $alignment, $columns, $column_width );

 		return $sizes;
 	};

 	// Hook this filter early, before default fitlers are run.
 	add_filter( 'wp_calculate_image_sizes', $filter, 9, 2 );

 	/*
 	 * A performance problem to still be solved with this approach is that
 	 * wp_calculate_image_sizes() will make a DB query to get the image metadata.
 	 * It does this to get the image width, which is needed to calculate
 	 * the sizes attribute. Currently, this function is called from `wp_filter_content_tags`
 	 * which has already primed the cache with the image metadata. That cache priming
 	 * will need to be hanlded earlier if sizes is calculated during block rendering.
 	 */
 	$sizes = wp_calculate_image_sizes(
 		// If we don't have a size slug, assume the full size was used.
 		$parsed_block['attrs']['sizeSlug'] ?? 'full',
 		null,
 		null,
 		$parsed_block['attrs']['id'] ?? 0
 	);

 	remove_filter( 'wp_calculate_image_sizes', $filter, 9 );

 	// Bail early if sizes are not calculated.
 	if ( ! $sizes ) {
 		return $block_content;
 	}

 	// Add the sizes attribute to the image tag here.
 	$processor = new WP_HTML_Tag_Processor( $block_content );
 	$processor->next_tag( 'img' );
 	$processor->set_attribute( 'sizes', $sizes );

 	$return = $processor->get_updated_html();

 	return $return;
 };

 /**
 * Hypothetical function to calculate better sizes.
 *
 * @param array  $size         The image size data.
 * @param string $alignment    The image alignment.
 * @param int    $columns      The column count.
 * @param string $column_width The column width.
 * @return string The sizes attribute value.
 */
 function wpp_better_sizes_calc( $size, $alignment, $columns, $column_width ) {
 	switch ( $alignment ) {
 		case 'full':
 			return '100vw';
 			break;
 		case 'wide':
 			// Hard coded wide size from TT4 theme for demo only.
 			if ( 2 === $columns && '50%' === $column_width ) { // Statically checking for column
 				return '(max-width: 640px) 100vw, 640px';	
 			}
 			return '(max-width: 1280px) 100vw, 1280px';
 			break;
 		default:
 			// Hard coded wide size from TT4 theme for demo only.
 			if ( 2 === $columns && '50%' === $column_width ) { // Statically checking for column
 				return '(max-width: 310px) 100vw, 310px';	
 			}
 			return '(max-width: 620px) 100vw, 620px';
 	}
 }