Walker_PageDropdown::start_el() WordPress Method

	public function start_el( &$output, $data_object, $depth = 0, $args = array(), $current_object_id = 0 ) {
		// Restores the more descriptive, specific name for use within this method.
		$page = $data_object;
		$pad  = str_repeat( ' ', $depth * 3 );

		if ( ! isset( $args['value_field'] ) || ! isset( $page->{$args['value_field']} ) ) {
			$args['value_field'] = 'ID';
		}

		$output .= "\t<option class=\"level-$depth\" value=\"" . esc_attr( $page->{$args['value_field']} ) . '"';
		if ( $page->ID == $args['selected'] ) {
			$output .= ' selected="selected"';
		}
		$output .= '>';

		$title = $page->post_title;
		if ( '' === $title ) {
			/* translators: %d: ID of a post. */
			$title = sprintf( __( '#%d (no title)' ), $page->ID );
		}

		/**
		 * Filters the page title when creating an HTML drop-down list of pages.
		 *
		 * @since 3.1.0
		 *
		 * @param string  $title Page title.
		 * @param WP_Post $page  Page data object.
		 */
		$title = apply_filters( 'list_pages', $title, $page );

		$output .= $pad . esc_html( $title );
		$output .= "</option>\n";
	}