class.jnews-meta-header

<?php
/**
 * @author : Jegtheme
 */

class JNews_Meta_Header {

    /**
     * @var JNews_Meta_Header
     */
    private static $instance;

    /**
     * @var JNews_Meta_Facebook
     */
    private $facebook_meta;

    /**
     * @var JNews_Meta_Twitter
     */
    private $twitter_meta;

    /**
     * @return JNews_Meta_Header
     */
    public static function getInstance() {
        if ( null === static::$instance ) {
            static::$instance = new static();
        }
        return static::$instance;
    }

    private function __construct() {
        add_action( 'wp', array( $this, 'instantiate_post' ), 1 );
        add_action( 'after_setup_theme', array( $this, 'load_metabox' ) );
        add_action( 'wp_head', array( $this, 'generate_social_meta' ), 1 );
    }

    public function load_metabox() {
        if ( class_exists( 'VP_Metabox' ) ) {
            global $pagenow;
            if ( $pagenow === 'post.php' || $pagenow === 'post-new.php' || ! is_admin() ) {
                new VP_Metabox( JNEWS_META_HEADER_DIR . '/metabox/social-meta.php' );
            }
        }
    }

    public function instantiate_post() {
        require_once 'class.jnews-meta-abstract.php';
        require_once 'class.jnews-meta-facebook.php';
        require_once 'class.jnews-meta-twitter.php';

        $post_id = get_the_ID();

        $this->facebook_meta = new JNews_Meta_Facebook( $post_id );
        $this->twitter_meta  = new JNews_Meta_Twitter( $post_id );
    }

    public function generate_social_meta() {
        if ( ! is_admin() && $this->facebook_meta instanceof JNews_Meta_Facebook && $this->twitter_meta instanceof JNews_Meta_Facebook ) {
            // Language is required for gettext.
            // Without it, 'gettext' or '_' will cause error instead of translate text.
            // phpcs:disable WordPress.PHP.DiscouragedPHPFunctions
            $locale      = function_exists( 'jnews_get_locale' ) ? jnews_get_locale() : get_locale();
            $prev_locale = getenv( 'LC_ALL' );
            putenv( 'LC_ALL=' . $locale );

            $this->facebook_meta->render_meta();
            $this->twitter_meta->render_meta();

            $this->add_fb_app_id();

            // Revert Language.
            if ( $prev_locale ) {
                putenv( 'LC_ALL=' . $prev_locale );
            } else {
                putenv( 'LC_ALL' );
            }
            // phpcs:enable WordPress.PHP.DiscouragedPHPFunctions
        }
    }

    public function add_fb_app_id() {
        $id = jnews_get_option( 'social_meta_fb_app_id', '' );

        if ( ! empty( $id ) ) {
            echo '<meta property="fb:app_id" content="' . $id . '">';
        }
    }
}