Document (NIF, NIE, CIF)

The NIF, the NIE or the CIF, with the control letter genuinely checked. 12345678A has the shape of a NIF and does not exist, because that number gets the Z: here it is checked, and the error says what is wrong ("The letter does not match the number") instead of an "invalid format" that helps nobody.

When to use it

• Customer sign-ups, billing details: any form that asks for a Spanish document. Each type with its own algorithm.
• What comes out through onChange is clean, without spaces, dots or hyphens, and in uppercase: 12345678Z.
• error for whatever the server says (a NIF that already has an account): it takes precedence over the one the field calculates.

When not to

• A foreign document (a passport, a tax number from another country): TextField.
• A bank account: IbanField.

Keyboard: that of a text field. The check fires on leaving the field, not on every key: marking a half-typed document in red is noise.

Accessibility: it is a TextField, with its label (by default "ID number"), its help and its error linked. When the document is valid, the help says so in words ("NIF is valid", "NIE is valid", "CIF is valid"), not with a color tick, and only if it really is, not if it "has the shape of" one.

Fine-tuning: no variables of its own: they are those of the field, --amset-field-*, with the digits in fixed width (amset-field--numeric).