Modifying an existing customizer control

This post shows you how to modify an existing customizer control — helpful for the solution was a Gist by Marcio Duarte.

In my case, I wanted to add an active_callback to the header image control to only show it if the user is on a static front page. To get this done, we only need one line of code:

/**
 * Set active callback for the header image control.
 */
$wp_customize->get_control( 'header_image' )->active_callback = 'slug_is_static_front_page';
Code language: PHP (php)

You can modify the other control properties accordingly — a few examples can be found in the above-linked Gist. For the sake of completeness here is the callback function:

/**
 * Check if we are on a static front page.
 *
 * @param WP_Customize_Control $control Control object.
 *
 * @return bool
 */
function slug_is_static_front_page( $control ) {
	/**
	 * Return true if is static front page.
	 */
	if ( is_front_page() && is_page() ) {
		return true;
	} else {
		return false;
	}
}
Code language: PHP (php)