com.vaadin.flow.function

Interface ValueProvider<SOURCE,TARGET>

Type Parameters:

SOURCE - the type of the object used to provide the value

TARGET - the type of the provided value

All Superinterfaces:

Function<SOURCE,TARGET>, Serializable, SerializableFunction<SOURCE,TARGET>

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface ValueProvider<SOURCE,TARGET>
extends SerializableFunction<SOURCE,TARGET>

A callback interface for providing values from a given source.

For example this interface can be implemented to simply extract a value with a getter, or to create a composite value based on the fields of the source object.

Since:

1.0.

Author:

Vaadin Ltd

Method Summary

Modifier and Type	Method and Description
TARGET	apply(SOURCE source) Provides a value from the given source object.
static <T> ValueProvider<T,T>	identity() Returns a value provider that always returns its input argument.

Methods inherited from interface java.util.function.Function

andThen, compose

Method Detail

identity

static <T> ValueProvider<T,T> identity()

Returns a value provider that always returns its input argument.

Specified by:

identity in interface Function<SOURCE,TARGET>

Specified by:

identity in interface SerializableFunction<SOURCE,TARGET>

Type Parameters:

T - the type of the input and output objects to the function

Returns:

a function that always returns its input argument

apply

TARGET apply(SOURCE source)

Provides a value from the given source object.

Specified by:

apply in interface Function<SOURCE,TARGET>

Parameters:

source - the source to retrieve the value from

Returns:

the value provided by the source