contract_variable_quantity

Purpose

Enables recurring contracts to calculate invoice quantities dynamically through user-defined formulas.

Features

contract.line.qty.formula: Users can register Python code formulas that derive invoice quantities using contract, line, and invoice context.
contract.line: Recurring invoice lines evaluate their assigned formula when the quantity type is variable, producing the quantity to invoice.
contract.contract: Contracts can skip generating invoice lines when formulas compute a zero quantity thanks to the skip zero qty option.
contract.template.line: Contract templates let users pick between fixed and variable quantities and select the appropriate formula for variable lines.