Show/hide section in theme customizer based on selection from another section

Question

I have a customizer option in my theme that has two sections: a drop-down menu and a text area. The drop down menu has three options: Active,Suspended and cancelled. I'm trying to find a way to hide the text area only if 'Suspended' is selected.

I've looked online and found something with active_callback but I'm unfamiliar with that callback.

Code so far:

function twsa_customizer( $wp_customize ) {
// Show schedule
$wp_customize->add_setting( 'twsa_show_schedule' );
$wp_customize->add_control( 'twsa_show_schedule', array(
'type' => 'select',
'label' => 'Show status',
'section' => 'twsa_show',
'choices' => array(
    'active' => 'Active',
    'suspended' => 'Suspended',
    'cancelled' => 'Cancelled',
),) );
$wp_customize->add_setting('twsa_show_suspend');
$wp_customize->add_control('twsa_show_suspend', array(
'description' => 'Reason for suspension',
'section' => 'twsa_show',
'type' => 'textarea',
'active_callback' => 'estore_is_cart',
));
}
add_action( 'customize_register', 'twsa_customizer', 20 );

Answer 1

In this example, estore_is_cart should return true only if 'suspended' === $wp_customize->get_setting( 'twsa_show_schedule' )->value(). Or in other words:

$wp_customize->add_control( 'twsa_show_suspend', array(
    'description' => 'Reason for suspension',
    'section' => 'twsa_show',
    'type' => 'textarea',
    'active_callback' => function() use ( $wp_customize ) {
        return 'suspended' === $wp_customize->get_setting( 'twsa_show_schedule' )->value();
    },
));