Summery Summery

Validate CSS.

Syntax Syntax

WP_Customize_Custom_CSS_Setting::validate( string $css )

Description Description

Checks for imbalanced braces, brackets, and comments. Notifications are rendered when the customizer state is saved.

Parameters Parameters


(string) (Required) The input string.

Return Return

(true|WP_Error) True if the input was validated, otherwise WP_Error.

Source Source

File: wp-includes/customize/class-wp-customize-custom-css-setting.php

	 * @return true|WP_Error True if the input was validated, otherwise WP_Error.
	public function validate( $css ) {
		$validity = new WP_Error();

		if ( preg_match( '#</?\w+#', $css ) ) {
			$validity->add( 'illegal_markup', __( 'Markup is not allowed in CSS.' ) );

		if ( ! $validity->has_errors() ) {
			$validity = parent::validate( $css );


Changelog Changelog

Version Description
4.9.0 Checking for balanced characters has been moved client-side via linting in code editor.
4.7.0 Introduced.


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