com.vaadin.flow.data.converter

Interface Converter<PRESENTATION,MODEL>

Type Parameters:

PRESENTATION - The presentation type.

MODEL - The model type.

All Superinterfaces:

Serializable

All Known Implementing Classes:

AbstractStringToNumberConverter, DateToLongConverter, DateToSqlDateConverter, LocalDateTimeToDateConverter, LocalDateToDateConverter, StringToBigDecimalConverter, StringToBigIntegerConverter, StringToBooleanConverter, StringToDateConverter, StringToDoubleConverter, StringToFloatConverter, StringToIntegerConverter, StringToLongConverter

public interface Converter<PRESENTATION,MODEL>
extends Serializable

Interface that implements conversion between a model and a presentation type.

Converters must not have any side effects (never update UI from inside a converter).

Since:

1.0.

Author:

Vaadin Ltd

Method Summary

Modifier and Type	Method and Description
default <T> Converter<PRESENTATION,T>	chain(Converter<MODEL,T> other) Returns a converter that chains together this converter with the given type-compatible converter.
Result<MODEL>	convertToModel(PRESENTATION value, ValueContext context) Converts the given value from model type to presentation type.
PRESENTATION	convertToPresentation(MODEL value, ValueContext context) Converts the given value from presentation type to model type.
static <P,M> Converter<P,M>	from(SerializableFunction<P,M> toModel, SerializableFunction<M,P> toPresentation, SerializableFunction<Exception,String> onError) Constructs a converter from two functions.
static <P,M> Converter<P,M>	from(SerializableFunction<P,Result<M>> toModel, SerializableFunction<M,P> toPresentation) Constructs a converter from a filter and a function.
static <T> Converter<T,T>	identity() Returns a converter that returns its input as-is in both directions.

Method Detail

convertToModel

Result<MODEL> convertToModel(PRESENTATION value,
                             ValueContext context)

Converts the given value from model type to presentation type.

A converter can optionally use locale to do the conversion.

Parameters:

value - The value to convert. Can be null

context - The value context for the conversion.

Returns:

The converted value compatible with the source type

convertToPresentation

PRESENTATION convertToPresentation(MODEL value,
                                   ValueContext context)

Converts the given value from presentation type to model type.

A converter can optionally use locale to do the conversion.

Parameters:

value - The value to convert. Can be null

context - The value context for the conversion.

Returns:

The converted value compatible with the source type

identity

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

Returns a converter that returns its input as-is in both directions.

Type Parameters:

T - the input and output type

Returns:

an identity converter

from

static <P,M> Converter<P,M> from(SerializableFunction<P,M> toModel,
                                 SerializableFunction<M,P> toPresentation,
                                 SerializableFunction<Exception,String> onError)

Constructs a converter from two functions. Any Exception instances thrown from the toModel function are converted into error-bearing Result objects using the given onError function.

Type Parameters:

P - the presentation type

M - the model type

Parameters:

toModel - the function to convert to model

toPresentation - the function to convert to presentation

onError - the function to provide error messages

Returns:

the new converter

See Also:

Result, Function

from

static <P,M> Converter<P,M> from(SerializableFunction<P,Result<M>> toModel,
                                 SerializableFunction<M,P> toPresentation)

Constructs a converter from a filter and a function.

Type Parameters:

P - the presentation type

M - the model type

Parameters:

toModel - the function to convert to model

toPresentation - the function to convert to presentation

Returns:

the new converter

See Also:

Function

chain

default <T> Converter<PRESENTATION,T> chain(Converter<MODEL,T> other)

Returns a converter that chains together this converter with the given type-compatible converter.

The chained converters will form a new converter capable of converting from the presentation type of this converter to the model type of the other converter.

In most typical cases you should not need this method but instead only need to define one converter for a binding using Binder.BindingBuilder.withConverter(Converter).

Type Parameters:

T - the model type of the resulting converter

Parameters:

other - the converter to chain, not null

Returns:

a chained converter