StartsWithValidator class

A validator that checks whether a given string starts with a specific prefix.

The StartsWithValidator ensures that the input string begins with the expected prefix, with support for case-sensitive and case-insensitive validation.

Example

final validator = StartsWithValidator(
  'Hello',
  message: 'Must start with "Hello"',
);

print(validator.validate('Hello World')); // null (valid)
print(validator.validate('hello world')); // 'Must start with "Hello"' (invalid)

final caseInsensitiveValidator = StartsWithValidator(
  'hello',
  message: 'Must start with "hello"',
  caseSensitivity: CaseSensitivity.insensitive,
);

print(caseInsensitiveValidator.validate('Hello World')); // null (valid)

Parameters

• prefix: The required prefix that the string must start with.
• message: The error message if validation fails.
• caseSensitivity: Defines whether the validation should be case-sensitive or not (default: CaseSensitivity.sensitive).

Behavior:

• If caseSensitivity is CaseSensitivity.insensitive, both the prefix and the input value are converted to lowercase before comparison.
• If the input value is null, validation fails.

Inheritance

• Object
• Validator<String>
• ValidatorWithMessage<String>
• StartsWithValidator

Constructors

StartsWithValidator(String prefix, {required String message, CaseSensitivity caseSensitivity = CaseSensitivity.sensitive})

Creates a StartsWithValidator with the given prefix, message, and caseSensitivity.

Properties

caseSensitivity → CaseSensitivity

Determines whether the validation is case-sensitive or not.

final

hashCode → int

The hash code for this object.

no setter, inherited

message → String

The error message to be returned when validation fails.

final, inherited

prefix → String

The required prefix for validation.

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

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(covariant String value) → String?

Validates the provided value.

override

Operators

operator ==(Object other) → bool

The equality operator.

inherited