Custom fields ‘context’ => ‘sustom’

The context attribute accepts ‘global’, which is also the default value, to set it as valid for all items. You can instead pass an event ID or an array of event IDs to limit to events.

There’s also a filter mt_apply_custom_field_rules that can be used to write a custom function that determines whether a field should show.

Filter documentation

Thank you for the reply, but I have a question: I wrote ‘context’ => ‘460’
where 460 is the ID event…but now I’m not able to see the custom field…

Can you share a link?

This is the link, you can find the widget calendar: https://www.bibliosestoragazzi.it/

This is my code:

 * Add a second custom field by adding more values to the array
 */
$array['choose_seats'] = array(
    'title'             => 'Età precisa - SOLO EVENTI BAMBINI E RAGAZZI:',
    'sanitize_callback' => 'custom_sanitize_callback',
    'display_callback'  => 'custom_display_callback',
    'input_type'        => 'text',
    'context'           => 'global'
);

return $array;

}

I’d like to change “global” in a specific id event…

Passing the ID as a string in the ‘context’ argument works for me, so I’m wondering if you have the wrong ID value? Where did you get it from?

You should be using the ID that’s shown in the My Tickets block in your calendar with the shortcode preview. It won’t be the visible ID for the calendar event.

Ok, the problem was that i use wrong ID value. Thank you for the solution!

Other question: how can I add more ID?

What do you mean by adding more ID? Do you mean to the context attribute, or do you mean adding additional events? You’d add additional IDs to the context attribute as an array of IDs, e.g.

'context' => [ 21,25,32,240 ]