Academy_product_languages

class academy_product_languages {

	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(
			'custom_language',
			__( 'Available in language', 'academy' ),
			array( $this, 'product_render_language_box' ),
			'product',
			'side',
			'high'
		);

	}

	public function product_render_language_box( $post ) {

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

		// Set default values.

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

		echo '	<tr>';
		echo '		<th><label for="custom_product_languagesproduct_language" class="custom_product_languagesproduct_language_label">' . __( '', 'academy' ) . '</label></th>';
		echo '		<td>';
		echo '			<label><input type="checkbox" name="custom_product_languagesDK" class="custom_product_languagesproduct_language_field" value="' . $custom_product_languagesDK . '" ' . checked( $custom_product_languagesDK, 'checked', false ) . '> ' . __( 'Dansk', 'academy' ) . '</label><br>';
		echo '			<label><input type="checkbox" name="custom_product_languagesUK" class="custom_product_languagesproduct_language_field" value="' . $custom_product_languagesUK . '" ' . checked( $custom_product_languagesUK, 'checked', false ) . '> ' . __( 'Engelsk', 'academy' ) . '</label><br>';
		echo '			<label><input type="checkbox" name="custom_product_languagesSE" class="custom_product_languagesproduct_language_field" value="' . $custom_product_languagesSE . '" ' . checked( $custom_product_languagesSE, 'checked', false ) . '> ' . __( 'Svensk', 'academy' ) . '</label><br>';
		echo '			<label><input type="checkbox" name="custom_product_languagesNO" class="custom_product_languagesproduct_language_field" value="' . $custom_product_languagesNO . '" ' . checked( $custom_product_languagesNO, 'checked', false ) . '> ' . __( 'Norsk', 'academy' ) . '</label><br>';
		echo '		</td>';
		echo '	</tr>';

		echo '</table>';

	}

	public function save_metabox( $post_id, $post ) {

		// Sanitize user input.
		$custom_product_languagesnew_dk = isset( $_POST[ 'custom_product_languagesdk' ] ) ? 'checked' : '';
		$custom_product_languagesnew_uk = isset( $_POST[ 'custom_product_languagesuk' ] ) ? 'checked' : '';
		$custom_product_languagesnew_se = isset( $_POST[ 'custom_product_languagesse' ] ) ? 'checked' : '';
		$custom_product_languagesnew_no = isset( $_POST[ 'custom_product_languagesno' ] ) ? 'checked' : '';

		// Update the meta field in the database.
		update_post_meta( $post_id, 'custom_product_languagesdk', $custom_product_languagesnew_dk );
		update_post_meta( $post_id, 'custom_product_languagesuk', $custom_product_languagesnew_uk );
		update_post_meta( $post_id, 'custom_product_languagesse', $custom_product_languagesnew_se );
		update_post_meta( $post_id, 'custom_product_languagesno', $custom_product_languagesnew_no );

	}

}

new academy_product_languages;