Enabling Additional CSS / custom-css

Question

Custom CSS is a feature since 4.7

Just choose the Additional CSS tab when customizing your current theme to get started!

The problem is that a theme developed a while back does not show the Additional CSS tab.

I happened to be using twentythirteen as a base for another project, and there it is, nothing anywhere in the functions.php is enabling it, it just works.

Anyone have any idea about how to enable it?

While I can use the following:

$wp_customize->add_setting( 'custom_theme_css', array( ) ); $wp_customize->add_control( 'custom_theme_css', array( 'label' => __( 'Custom Theme CSS' ), 'type' => 'textarea', 'section' => 'custom_css', ) ); $wp_customize->add_section( 'custom_css', array( 'title' => __( 'Custom CSS' ), 'description' => __( 'Add custom CSS here' ), 'panel' => '', // Not typically needed. 'priority' => 160, 'capability' => 'edit_theme_options', 'theme_supports' => '', // Rarely needed. ) ); 

I am essentially creating a new setting, rather than using the new core feature.

I want to enable the core, something like $wp_customize->add_section('custom_css');

Answer 1

Lol, coming back to my own post 3 years later looking for answers.

Deactivating plugins did nothing, but ended up finding WP_Customize_Code_Editor_Control which has options for code_type.

So here is a manual method for adding a proper CSS editor to a theme. This probably only useful for updating older themes that were already installed.

add_action( 'customize_register', function($wp_customize) { $wp_customize->add_setting( 'custom_css', array( ) ); $wp_customize->add_control( new WP_Customize_Code_Editor_Control( $wp_customize,'custom_css', array( 'label' => __( 'Custom CSS' ), 'code_type' => 'css', 'section' => 'custom_css', 'settings' => 'custom_css', ) )); $wp_customize->add_section( 'custom_css', array( 'title' => __( 'Custom CSS' ), 'description' => __( 'Add custom CSS here' ), 'panel' => '', // Not typically needed. 'priority' => 160, 'capability' => 'edit_theme_options', 'theme_supports' => '', // Rarely needed. ) ); $custom_css = get_theme_mod( 'custom_css', '' ); wp_register_style( 'custom-css', false ); wp_enqueue_style( 'custom-css' ); wp_add_inline_style( 'custom-css', $custom_css ); });