Dynamic Required Fields

What does this script do?

Dynamically sets field requirements based on document content. In this example: when the invoice currency is not EUR, the exchange rate field becomes mandatory and visible. For EUR invoices, the exchange rate field is hidden and optional.

Trigger

ON_FIELD_CHANGE on document type INVOICE

Full Script

# Read current currency
currency = get_field_value(document_data, "currency", "EUR")

# Foreign currency: exchange rate is required and visible
if currency and currency != "EUR":
    set_is_required(document_data, "exchange_rate", True)
    set_is_hidden(document_data, "exchange_rate", False)
else:
    # EUR: exchange rate is optional and hidden
    set_is_required(document_data, "exchange_rate", False)
    set_is_hidden(document_data, "exchange_rate", True)

Variation: Purchase invoice vs. cost invoice

po = get_field_value(document_data, "purchase_order", "")

if po and po.strip():
    # Purchase invoice: PO number is required
    set_field_value(document_data, "invoice_category", "PURCHASE_INVOICE")
    set_is_required(document_data, "purchase_order", True)
else:
    # Cost invoice: PO number not needed, hide table
    set_field_value(document_data, "invoice_category", "COST_INVOICE")
    set_is_required(document_data, "purchase_order", False)
    delete_tables(document_data)

Step-by-Step Explanation

1. Read the controlling field (currency in this case)

2. Apply business rules — different field requirements based on the value

3. Set visibility — hide irrelevant fields to keep the UI clean

4. Set requirements — make relevant fields mandatory

Trigger choice: ON_FIELD_CHANGE runs every time a user modifies a field, so the requirements update in real-time. AFTER_FORMATTING only runs once after initial extraction.

Functions Used

• get_field_value() — Read controlling field

• set_is_required() — Set field as mandatory/optional

• set_is_hidden() — Show/hide fields

• set_field_value() — Set category field

• delete_tables() — Remove tables for cost invoices