Limit SearchWP results to the current bbPress Forum when applicable

searchwp-customizations.php

<?php

// Customize native WordPress search form to include current bbPress Forum ID if applicable.
add_filter( 'get_search_form', function( $markup ) {
	if ( ! function_exists( 'bbp_get_forum_id' ) ) {
		return $markup;
	}

	$forum_id = isset( $_REQUEST['swpforumid'] ) ? absint( $_REQUEST['swpforumid'] ) : bbp_get_forum_id();

	if ( empty( $forum_id ) ) {
		return $markup;
	}

	return str_replace( '</form>',
		'<input type="hidden" name="swpforumid" value="' . esc_attr( $forum_id ) . '" /></form>',
		$markup
	);
} );

// Limit SearchWP results to the current bbPress Forum when applicable.
add_filter( 'searchwp\query\mods', function( $mods, $query ) {
	if ( ! isset( $_REQUEST['swpforumid'] ) ) {
		return $mods;
	}

	$mod = new \SearchWP\Mod(
		\SearchWP\Utils::get_post_type_source_name( 'post' )
	);

	$mod->set_where( [ [
		'column'  => 'id',
		'value'   => absint( $_REQUEST['swpforumid'] ),
		'compare' => '=',
		'type'    => 'NUMERIC',
	] ] );

	$mods[] = $mod;

	return $mods;
}, 30, 2 );