.length()

Passes when value.length equals length. Throws ArgumentError for a negative length.

Signature

StringValidator<O> length(int length, {String? message, MessageBuilder? messageBuilder})

Parameters

Parameter	Type	Meaning
length	int	The only accepted length. params['length'].
message	String?	Replaces the default error message.
messageBuilder	MessageBuilder?	Builds the message from the issue. message wins when both are given. See Message builders.

Issue

Code invalidLength. Default message: value must be exactly 3 characters long. value is replaced by the field name when there is one.

Code generation

@HasLength(n). Put the annotation on the constructor parameter or the field.

Example

Hand-written

final iso = l.string().length(3);

Generated

@HasLength(2) required String countryCode, // l.string().length(2).required()

iso.validate(input)+1-1

1. +valid: 'abc'
2. -invalid: 'abcd'value must be exactly 3 characters long