RequiredRule class

Rule that ensures a value is not null, empty, or whitespace-only.

Inheritance

Constructors

RequiredRule(String message)
Creates a new RequiredRule with the given message.
const

Properties

hashCode → int
The hash code for this object.
no setterinherited
message → String
The error message to return if validation fails.
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
A string representation of this object.
inherited
validate(String? value) → String?
Validates the value and returns an error string if it fails, or null if it passes.
override

Operators

operator ==(Object other) → bool
The equality operator.
inherited