apply_filters( 'language_attributes', string $output, string $doctype )

使用示例

• 示例1

  下面是一个函数，用于强制HTML lang属性的区域设置，而不破坏其他属性，如dir

  /**
   * Forces the site locale for the HTML lang attribute.
   * 
   * @param string $locale the locale to set with the following format : "en-US"
   * @return void
   */
  function wpdocs_force_site_locale( $locale = 'en-US' ) {
  	add_filter( 'language_attributes', function( $output ) use ( $locale ) {
  		// match the lang attribute and replace it with the new locale
  		$lang_regex = '/lang="([a-zA-Z-_]+)"/';
  		$output     = preg_replace( $lang_regex, 'lang="' . $locale . '"', $output );
  
  		// update the xml:lang attribute as well
  		$xml_lang_regex = '/xml:lang="([a-zA-Z-_]+)"/';
  		$output         = preg_replace( $xml_lang_regex, 'xml:lang="' . $locale . '"', $output );
  		
  		return $output;
  	} );
  }