/** * navigation.js * * Handles toggling the navigation menu for small screens. */ ( function() { var container, button, menu; container = document.getElementById( 'site-navigation' ); if ( ! container ) { return; } button = container.getElementsByTagName( 'button' )[0]; if ( 'undefined' === typeof button ) { return; } menu = container.getElementsByTagName( 'ul' )[0]; // Hide menu toggle button if menu is empty and return early. if ( 'undefined' === typeof menu ) { button.style.display = 'none'; return; } if ( -1 === menu.className.indexOf( 'nav-menu' ) ) { menu.className += ' nav-menu'; } button.onclick = function() { if ( -1 !== container.className.indexOf( 'toggled' ) ) { container.className = container.className.replace( ' toggled', '' ); } else { container.className += ' toggled'; } }; } )();