Times | Meta | SEO

class SEO_ {

	public function __construct() {

		if ( is_admin() ) {
			add_action( 'load-post.php',     array( $this, 'init_metabox' ) );
			add_action( 'load-post-new.php', array( $this, 'init_metabox' ) );
		}

	}

	public function init_metabox() {

		add_action( 'add_meta_boxes',        array( $this, 'add_metabox' )         );
		add_action( 'save_post',             array( $this, 'save_metabox' ), 10, 2 );

	}

	public function add_metabox() {

		add_meta_box(
			'SEO',
			__( 'SEO items', 'text_domain' ),
			array( $this, 'render_metabox' ),
			array( 'attraction', ' bar', ' hotel', ' article', 'restaurant ' ),
			'advanced',
			'low'
		);

	}

	public function render_metabox( $post ) {

		// Retrieve an existing value from the database.
		$seo_seo_meta_description = get_post_meta( $post->ID, 'seo_seo_meta_description', true );

		// Set default values.
		if( empty( $seo_seo_meta_description ) ) $seo_seo_meta_description = 'default';

		// Form fields.
		echo '<table class="form-table">';

		echo '	<tr>';
		echo '		<th><label for="SEO_seo_meta_description" class="SEO_seo_meta_description_label">' . __( 'Meta Description', 'text_domain' ) . '</label></th>';
		echo '		<td>';
		echo '			<textarea id="SEO_seo_meta_description" name="SEO_seo_meta_description" class="SEO_seo_meta_description_field" placeholder="' . esc_attr__( 'add description', 'text_domain' ) . '">' . $SEO_seo_meta_description . '</textarea>';
		echo '			<p class="description">' . __( 'This is the seo friendly description', 'text_domain' ) . '</p>';
		echo '		</td>';
		echo '	</tr>';

		echo '</table>';

	}

	public function save_metabox( $post_id, $post ) {

		// Sanitize user input.
		$seo_new_seo_meta_description = isset( $_POST[ 'seo_seo_meta_description' ] ) ? sanitize_text_field( $_POST[ 'seo_seo_meta_description' ] ) : '';

		// Update the meta field in the database.
		update_post_meta( $post_id, 'seo_seo_meta_description', $seo_new_seo_meta_description );

	}

}

new SEO_;