com.vaadin.flow.data.validator

Class AbstractValidator<T>

java.lang.Object

com.vaadin.flow.data.validator.AbstractValidator<T>

Type Parameters:

T - The value type

All Implemented Interfaces:

Validator<T>, Serializable, BiFunction<T,ValueContext,ValidationResult>

Direct Known Subclasses:

RangeValidator, RegexpValidator, StringLengthValidator

public abstract class AbstractValidator<T>
extends Object
implements Validator<T>

An abstract base class for typed validators.

Since:

1.0.

Author:

Vaadin Ltd

See Also:

Serialized Form

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractValidator(String errorMessage) Constructs a validator with the given error message.

Method Summary

Modifier and Type	Method and Description
protected String	getMessage(T value) Returns the error message for the given value.
protected ValidationResult	toResult(T value, boolean isValid) A helper method for creating a Result from a value and a validity flag.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.vaadin.flow.data.binder.Validator

alwaysPass, apply, from, from, from, from

Methods inherited from interface java.util.function.BiFunction

andThen

Constructor Detail

AbstractValidator

protected AbstractValidator(String errorMessage)

Constructs a validator with the given error message. The substring "{0}" is replaced by the value that failed validation.

Parameters:

errorMessage - the message to be included in a failed result, not null

Method Detail

getMessage

protected String getMessage(T value)

Returns the error message for the given value.

Parameters:

value - an invalid value

Returns:

the formatted error message

toResult

protected ValidationResult toResult(T value,
                                    boolean isValid)

A helper method for creating a Result from a value and a validity flag. If the flag is true, returns Result.ok, otherwise yields Result.error bearing the error message returned by getMessage(Object).

For instance, the following apply method only accepts even numbers:

 @Override
 public Result<T> apply(Integer value) {
     return toResult(value, value % 2 == 0);
 }
 

Parameters:

value - the validated value

isValid - whether the value is valid or not

Returns:

the validation result