wp-bootstrap/inc/Block/WidgetRenderer.php

<?php
/**
 * Widget Renderer.
 *
 * Transforms sidebar widget wrappers into Bootstrap 5 card components
 * and adjusts block widget content (headings, lists) for Bootstrap styling.
 *
 * Card structure:
 *   With title:    card → card-body → h4.card-title → content
 *   Without title: card → card-body → content
 *
 * The title is placed inside card-body as a card-title. This avoids
 * broken HTML when widgets omit the title (WordPress skips before_title
 * and after_title entirely when there is no title to output).
 *
 * @package WPBootstrap\Block
 * @since   1.1.0
 */

namespace WPBootstrap\Block;

use WP_HTML_Tag_Processor;

class WidgetRenderer
{
    /**
     * Register filters for widget output transformation.
     */
    public function __construct()
    {
        if ( is_admin() || wp_doing_ajax() ) {
            return;
        }

        if ( defined( 'REST_REQUEST' ) && REST_REQUEST ) {
            return;
        }

        add_filter( 'dynamic_sidebar_params', [ $this, 'wrapWidgetInCard' ] );
        add_filter( 'widget_block_content', [ $this, 'processBlockWidgetContent' ], 10, 3 );
    }

    /**
     * Restructure widget wrapper as a Bootstrap card.
     *
     * Uses card-body for all content with card-title for the heading.
     * This structure works correctly whether or not the widget outputs a title.
     *
     * Note: WordPress runs sprintf on before_widget BEFORE this filter,
     * so %1$s/%2$s are already replaced. We must use the processed values.
     *
     * @param array $params Sidebar parameters.
     * @return array Modified parameters.
     */
    public function wrapWidgetInCard( array $params ): array
    {
        $widgetId     = $params[0]['widget_id'] ?? '';
        $beforeWidget = $params[0]['before_widget'] ?? '';

        // Extract widget-type classes (e.g. widget_block, widget_search)
        // from the already-processed before_widget, skipping generic
        // wrapper classes that we're replacing.
        $widgetClasses = '';
        if ( preg_match( '/class="([^"]*)"/', $beforeWidget, $matches ) ) {
            $original = array_filter( explode( ' ', $matches[1] ) );
            $skip     = [ 'widget', 'mb-4' ];
            $kept     = array_diff( $original, $skip );
            $widgetClasses = implode( ' ', $kept );
        }

        $params[0]['before_widget'] = sprintf(
            '<div id="%s" class="card mb-3 widget %s"><div class="card-body">',
            esc_attr( $widgetId ),
            esc_attr( $widgetClasses )
        );
        $params[0]['after_widget']  = '</div></div>';
        $params[0]['before_title']  = '<h4 class="card-title h6 text-uppercase fw-semibold">';
        $params[0]['after_title']   = '</h4>';

        return $params;
    }

    /**
     * Process block widget content to downgrade h2 headings to h4.
     *
     * Block widgets render their headings as <h2 class="wp-block-heading">.
     * Inside a sidebar card, h2 is too large — replace with h4 for proper
     * visual hierarchy.
     *
     * @param string     $content  Widget block content.
     * @param array      $instance Widget instance data.
     * @param \WP_Widget $widget   Widget object.
     * @return string Modified content.
     */
    public function processBlockWidgetContent( string $content, array $instance, \WP_Widget $widget ): string
    {
        if ( empty( $content ) ) {
            return $content;
        }

        // Replace <h2 ... wp-block-heading ...>...</h2> with <h4> pairs.
        // Single regex ensures only headings with wp-block-heading class are
        // downgraded, preventing mismatched tags if a widget contains other h2s.
        $content = preg_replace(
            '/<h2(\s+class="[^"]*wp-block-heading[^"]*"[^>]*)>(.*?)<\/h2>/s',
            '<h4$1>$2</h4>',
            $content
        );

        return $content;
    }
}