Custom fields that call a function

Hi, I found a youtube channel showing different coding examples when trying to make auto-populating relate fields. This video shows that you’re able to call a php function that you define in /custom/Extension/application/Ext/Utils/<custom_util_name>.php, but I don’t see any ‘function’ attributes in the metadata or vardef sections of sugarcrm/suitecrm docs for custom fields. Does anyone have experience using fields in this way? My issue is that SuiteCRM recognizes the definition of the function created in my custom_util.php, but there is no interaction the field

What exactly are you trying to achieve? Is it JavaScript function you need to call?

I’m looking to pull data from other modules and do math without needing to refresh

@lucid
You can add javascript with ajax call to entrypoint. Documentation about entrypoint here: