Add child PDF snippets to SearchWP result excerpt

searchwp-customizations.php

<?php

// Add child PDF snippets to SearchWP result excerpt.
add_filter( 'get_the_excerpt', function( $excerpt ) {
	global $post;

	if ( ! $post instanceof WP_Post || ! is_search() ||  post_password_required() || $post->searchwp_excerpt_found ) {
		return $excerpt;
	}

	$post->searchwp_excerpt_found = true;

	$attached_pdfs = get_attached_media( 'application/pdf', $post->ID );

	if ( empty( $attached_pdfs ) ) {
		return $excerpt;
	}

	// The number of words to include in PDF excerpt.
	$pdf_excerpt_length = 20;

	foreach ( $attached_pdfs as $attached_pdf ) {
		$source    = \SearchWP\Utils::get_post_type_source_name( 'attachment' );
		$pdf_entry = new \SearchWP\Entry( $source, $attached_pdf->ID, false, false );

		$pdf_excerpt = \SearchWP\Sources\Post::get_global_excerpt(
			$pdf_entry, get_search_query(), $pdf_excerpt_length
		);

		if ( \SearchWP\Settings::get( 'highlighting', 'boolean' ) ) {
			$pdf_excerpt = \SearchWP\Highlighter::apply( $pdf_excerpt, get_search_query() );
		}

		if ( ! empty( $pdf_excerpt ) ) {
			$pdf_label = get_the_title( $attached_pdf->ID );
			$excerpt   .= '<br /><br /><strong>' . wp_kses_post( $pdf_label )
					. '</strong>: ' . wp_kses_post( $pdf_excerpt );
		}
	}

	return $excerpt;
} );