pre_wp_nav_menu │ filter-hook │ WP 3.9.0

Returning a non-null value from the filter will short-circuit wp_nav_menu(), echoing that value if $args->echo is true, returning that value otherwise.

Usage

add_filter( 'pre_wp_nav_menu', 'wp_kama_pre_wp_nav_menu_filter', 10, 2 );

/**
 * Function for `pre_wp_nav_menu` filter-hook.
 * 
 * @param string|null $output Nav menu output to short-circuit with.
 * @param stdClass    $args   An object containing wp_nav_menu() arguments.
 *
 * @return string|null
 */
function wp_kama_pre_wp_nav_menu_filter( $output, $args ){

	// filter...
	return $output;
}

$output(string|null)

Nav menu output to short-circuit with.
Default: null

$args(stdClass)

An object containing wp_nav_menu() arguments.

Changelog

Where the hook is called

$nav_menu = apply_filters( 'pre_wp_nav_menu', null, $args );

Where the hook is used in WordPress