[Ask] Accessing options of a field from another field

[ghost]

Hello,

I have a custom field extended from Text field. I would want to access the options of a Select field on the same form from my custom text field.

I tried to implement postRender function in my custom field and do a lookup from there (traversing up the data structure using the parent property), but it seems that childrenByPropertyId objects in the data structure are empty at the time when postRender is run.

What would be the best strategy to implement this?