felixarntz/theme-boilerplate

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

/**
 * Theme icons handling.
 *
 * @since 1.0.0
 */
final class Super_Awesome_Theme_Icons extends Super_Awesome_Theme_Theme_Component_Base {

    /**
     * Whether SVG icons are used on the current page.
     *
     * @since 1.0.0
     * @var bool
     */
    private $needs_svg = false;

    /**
     * Gets SVG markup for a specific icon.
     *
     * @since 1.0.0
     *
     * @param string $icon SVG icon identifier.
     * @param array  $args {
     *     Optional. Additional parameters for displaying the SVG.
     *
     *     @type string $title SVG title. Default empty.
     *     @type string $desc  SVG description. Default empty.
     *     @type bool   $fallback Whether to create fallback markup. Default false.
     * }
     * @return string SVG markup for the icon.
     */
    public function get_svg( $icon, array $args = array() ) {
        $this->needs_svg = true;

        $args = wp_parse_args( $args, array(
            'title'    => '',
            'desc'     => '',
            'fallback' => false,
        ) );

        $unique_id       = '';
        $aria_hidden     = ' aria-hidden="true"';
        $aria_labelledby = '';

        if ( ! empty( $args['title'] ) ) {
            $unique_id       = uniqid();
            $aria_hidden     = '';
            $aria_labelledby = ' aria-labelledby="title-' . $unique_id . '"';

            if ( ! empty( $args['desc'] ) ) {
                $aria_labelledby = ' aria-labelledby="title-' . $unique_id . ' desc-' . $unique_id . '"';
            }
        }

        $svg = '<svg class="icon icon-' . esc_attr( $icon ) . '"' . $aria_hidden . $aria_labelledby . ' role="img">';

        if ( ! empty( $args['title'] ) ) {
            $svg .= '<title id="title-' . $unique_id . '">' . esc_html( $args['title'] ) . '</title>';

            if ( ! empty( $args['desc'] ) ) {
                $svg .= '<desc id="desc-' . $unique_id . '">' . esc_html( $args['desc'] ) . '</desc>';
            }
        }

        // The whitespace is a work around to a keyboard navigation bug in Safari 10. See https://core.trac.wordpress.org/ticket/38387.
        $svg .= ' <use href="#icon-' . esc_attr( $icon ) . '" xlink:href="#icon-' . esc_attr( $icon ) . '"></use> ';

        if ( $args['fallback'] ) {
            $svg .= '<span class="svg-fallback icon-' . esc_attr( $icon ) . '"></span>';
        }

        $svg .= '</svg>';

        return $svg;
    }

    /**
     * Prints the SVG content.
     *
     * @since 1.0.0
     */
    public function print_svg() {
        $svg_icons = get_theme_file_path( '/assets/dist/images/icons.svg' );

        if ( ! file_exists( $svg_icons ) ) {
            return;
        }

        require_once( $svg_icons );
    }

    /**
     * Prints the SVG content if necessary.
     *
     * This should be called before the closing body tag of the page, so that icons loaded
     * can reference the file.
     *
     * The content is only printed if at least one icon is used in the current page.
     *
     * @since 1.0.0
     */
    public function maybe_print_svg() {
        if ( ! $this->needs_svg ) {
            return;
        }

        $this->print_svg();
    }

    /**
     * Adds hooks and runs other processes required to initialize the component.
     *
     * @since 1.0.0
     */
    protected function run_initialization() {
        add_action( 'wp_footer', array( $this, 'maybe_print_svg' ), 9999, 0 );
        add_action( 'admin_footer', array( $this, 'maybe_print_svg' ), 9999, 0 );
        add_action( 'login_footer', array( $this, 'maybe_print_svg' ), 9999, 0 );
    }
}