collectDataFields
collectDataFields(
nodes,data): (InputField|TextareaField|NumberField|ChoiceField)[]
Depth-first walk of a node tree, flattened to the data-carrying fields that are currently
visible given data — a Fieldset/Row is walked through unconditionally, but a Variant
contributes only its currently-selected branch’s fields, so a field inside a branch that isn’t
shown never gets treated as present or required.
data is required, not optional, deliberately: a caller that doesn’t have the respondent’s current
answers yet has no correct default to fall back to (an empty object would make every Variant
resolve as if nothing had been answered, which is only sometimes what a caller wants).
Parameters
Section titled “Parameters”FormNode[]
Returns
Section titled “Returns”(InputField | TextareaField | NumberField | ChoiceField)[]