applyDerivations

Applies all pending derivations from a collection.

This function processes derivations in order, evaluating conditions and computing values. It handles loop prevention through:

1. Chain tracking (prevents same derivation from running twice in one cycle)
2. Value equality checks (skips if target already has computed value)
3. Max iteration limit (safety fallback)

Presentation

function applyDerivations(
  collection: DerivationCollection,
  context: DerivationApplicatorContext,
  changedFields?: Set<string> | undefined,
): DerivationProcessingResult;

Returns

Parameters

const result = applyDerivations(collection, {
  formValue: formValueSignal,
  rootForm: form(),
  derivationFunctions: customFnConfig?.derivations,
  logger: inject(DynamicFormLogger),
});

if (result.maxIterationsReached) {
  console.warn('Possible derivation loop detected');
}