de.saxsys.mvvmfx.utils.validation

Class FunctionBasedValidator<T>

java.lang.Object

de.saxsys.mvvmfx.utils.validation.FunctionBasedValidator<T>

Type Parameters:

T - the generic value of the source observable.

All Implemented Interfaces:

Validator

public class FunctionBasedValidator<T>
extends Object
implements Validator

This Validator implementation uses functions to validate the values of an observable. You need to define a observable value as source that contains the value that should be validated.

There are two "flavours" of using this validator: Using a Predicate or a Function for validation.

The variant with Predicate is used for simple use cases where you provide a predicate that simply tells the validator, if the given value is valid or not. If it is invalid, the given ValidationMessage will be present in the ValidationStatus of this validator.

The variant with Function is used for use cases where different messages should be shown under specific conditions. Instead of only returning true or false the function has to return a ValidationMessage for a given input value if it is invalid. The returned message will then be present in the validation status. If the input value is valid and therefore no validation message should be shown, the function has to return null instead.

For more complex validation logic like cross field validation you can use the ObservableRuleBasedValidator as an alternative.

Constructor Summary

Constructors

Constructor and Description
FunctionBasedValidator(javafx.beans.value.ObservableValue<T> source, java.util.function.Function<T,ValidationMessage> function) Creates a validator that uses a Function for validation.
FunctionBasedValidator(javafx.beans.value.ObservableValue<T> source, java.util.function.Predicate<T> predicate, ValidationMessage message) Creates a validator that uses a Predicate for validation.

Method Summary

Modifier and Type	Method and Description
ValidationStatus	getValidationStatus() Returns the validation status of this validator.

Methods inherited from class java.lang.Object

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

Constructor Detail

FunctionBasedValidator

public FunctionBasedValidator(javafx.beans.value.ObservableValue<T> source,
                              java.util.function.Function<T,ValidationMessage> function)

Creates a validator that uses a Function for validation. The function has to return a ValidationMessage for a given input value or null if the value is valid.

Parameters:

source - the observable value that will be validated.

function - the validation function.

FunctionBasedValidator

public FunctionBasedValidator(javafx.beans.value.ObservableValue<T> source,
                              java.util.function.Predicate<T> predicate,
                              ValidationMessage message)

Creates a validator that uses a Predicate for validation. The predicate has to return true if the input value is valid. Otherwise false.

When the predicate returns false, the given validation message will be used.

Parameters:

source - the observable value that will be validated.

predicate - the validation predicate.

message - the message that will be used when the predicate doesn't match

Method Detail

getValidationStatus

public ValidationStatus getValidationStatus()

Description copied from interface: Validator

Returns the validation status of this validator. The status will be updated when the validator re-validates the inputs of the user.

Specified by:

getValidationStatus in interface Validator

Returns:

the state.