felixarntz/theme-boilerplate

<?php
/**
 * Super_Awesome_Theme_AMP_Sanitizer class
 *
 * @package Super_Awesome_Theme
 * @license GPL-2.0-or-later
 * @link    https://super-awesome-author.org/themes/super-awesome-theme/
 */

/**
 * Class performing theme-specific AMP sanitization.
 *
 * @since 1.0.0
 */
final class Super_Awesome_Theme_AMP_Sanitizer extends AMP_Base_Sanitizer {

    /**
     * XPath for the DOMDocument.
     *
     * @since 1.0.0
     * @var DOMXPath
     */
    protected $xpath;

    /**
     * Sanitizes the HTML contained in the DOMDocument.
     *
     * @since 1.0.0
     */
    public function sanitize() {
        $this->xpath = new DOMXPath( $this->dom );

        $this->add_amp_indicator();
        $this->force_svg_support();
        $this->fix_header_image();
        $this->support_mobile_menu_toggle();
        $this->support_side_navbar_toggle();
    }

    /**
     * Adds an AMP indicator class to the html tag.
     *
     * @since 1.0.0
     */
    protected function add_amp_indicator() {
        $this->dom->documentElement->setAttribute(
            'class',
            'amp ' . $this->dom->documentElement->getAttribute( 'class' )
        );
    }

    /**
     * Forces SVG support, replacing no-svg class name with svg class name.
     *
     * @since 1.0.0
     */
    protected function force_svg_support() {
        $this->dom->documentElement->setAttribute(
            'class',
            preg_replace(
                '/(^|\s)no-svg(\s|$)/',
                ' svg ',
                $this->dom->documentElement->getAttribute( 'class' )
            )
        );
    }

    /**
     * Fixes the header image appearance by adjusting its layout attribute.
     *
     * @since 1.0.0
     */
    protected function fix_header_image() {
        $header_image = $this->xpath->query( '//div[@id = "wp-custom-header"]//amp-img' );

        if ( ! $header_image->length ) {
            return;
        }

        $header_image = $header_image->item( 0 );
        $header_image->setAttribute( 'layout', 'responsive' );
    }

    /**
     * Adds support for the mobile menu toggle, which is otherwise controlled by JS.
     *
     * @since 1.0.0
     */
    protected function support_mobile_menu_toggle() {
        $state_id = $this->args['state_id'];

        $navigation = $this->dom->getElementById( 'site-navigation' );
        if ( ! $navigation ) {
            return;
        }

        $button = $this->xpath->query( '//nav[@id = "site-navigation"]//button[ contains( @class, "menu-toggle" ) ]' );

        $navigation_class = $navigation->getAttribute( 'class' );

        $navigation->setAttribute(
            AMP_DOM_Utils::get_amp_bind_placeholder_prefix() . 'class',
            "{$state_id}.mobileMenuExpanded ? '{$navigation_class} toggled' : '{$navigation_class}'"
        );

        if ( ! $button->length ) {
            $navigation->setAttribute( 'class', $navigation_class . ' toggled' );
            return;
        }

        $button = $button->item( 0 );

        $button->setAttribute( 'on', "tap:AMP.setState( { {$state_id}: { mobileMenuExpanded: ! {$state_id}.mobileMenuExpanded } } )" );
        $button->setAttribute(
            AMP_DOM_Utils::get_amp_bind_placeholder_prefix() . 'aria-expanded',
            "{$state_id}.mobileMenuExpanded ? 'true' : 'false'"
        );
    }

    /**
     * Adds support for the side navbar toggle as necessary, which is otherwise controlled by JS.
     *
     * @since 1.0.0
     */
    protected function support_side_navbar_toggle() {
        $state_id = $this->args['state_id'];

        $navbar = $this->dom->getElementById( 'site-navbar' );
        if ( ! $navbar ) {
            return;
        }

        $button = $this->xpath->query( '//div[@id = "site-navbar"]//button[ contains( @class, "site-navbar-toggle" ) ]' );

        $navbar_class = $navbar->getAttribute( 'class' );

        $navbar->setAttribute(
            AMP_DOM_Utils::get_amp_bind_placeholder_prefix() . 'class',
            "{$state_id}.sideNavbarExpanded ? '{$navbar_class} toggled' : '{$navbar_class}'"
        );

        if ( ! $button->length ) {
            $navbar->setAttribute( 'class', $navbar_class . ' toggled' );
            return;
        }

        $button = $button->item( 0 );

        $button->setAttribute( 'on', "tap:AMP.setState( { {$state_id}: { sideNavbarExpanded: ! {$state_id}.sideNavbarExpanded } } )" );
        $button->setAttribute(
            AMP_DOM_Utils::get_amp_bind_placeholder_prefix() . 'aria-expanded',
            "{$state_id}.sideNavbarExpanded ? 'true' : 'false'"
        );
    }
}