Assigning Data to Fields
Return field values from your handler to populate or update fields in the running form. The SDK merges your response formData onto the current form state.
Prepopulating Widgets with Default Values
When a form loads, the SDK calls Form_onInit(bool isInitialLoad) with isInitialLoad: true. This is the place to fetch data from your database and assign values via record.SetField() — the SDK will render whatever you set before returning the response to the frontend.
Prepopulating Select Boxes with Values
Select (dropdown) widgets display options that come from your backend at load time. You supply these via the fieldAllowedValues dictionary in your response.
Autocomplete
Autocomplete allows users to search a large dataset by typing, with your backend filtering and returning matching options dynamically. It is powered by the onChange event on a Select widget configured for autocomplete mode.