Implemente un renderizador de columnas para Vaadin 8 Grid
losMarco Vaadin guía tiene unpágina que describe cómo usar los Renders de columna en unRejilla Vaadin. Yesta página describe la implementación de renderizadores, pero muy brevemente.
Quiero implementar unInstantRenderer para complementar el conjunto parcial de renderizadores java.time agregados en Vaadin 8.1. Se agregaron renderizadores paraLocalDate & LocalDateTime pero no paraInstant, OffsetDateTimeyZonedDateTime. Para miInstant Renderizador Actualmente, simplemente estoy aplicando la zona horaria predeterminada actual (ZoneId) conseguir unZonedDateTime en el que llamo eltoString método. Se podría hacer más, pero esto es solo para comenzar.
Entonces mi código debe ser muy similar al proporcionadoLocalDateTimeRenderer. Estoy tratando de seguir ese código como guía.
Al buscar el código fuente de Vaadin y leer el documento, parece que necesito tres piezas de código fuente:
InstantRenderer ( Similar aLocalDateTimeRenderer )InstantRendererConnector ( Similar aLocalDateTimeRendererConnector )InstantRendererState ( Similar aLocalDateTimeRendererState )He hecho esto, y todo se compila. Pero mi tabla no se procesa, todo lo que obtengo es un cuadro blanco vacío en la página. No aparecen errores en la consola o en los registros. Si elimino mi uso de miInstantRenderery vuelvo a dejar que miInstant los objetos se renderizarán por defectotoString métodos, todo está bien y la tabla aparece como se esperaba. Entonces sé que mi renderizador personalizado tiene la culpa.
Soy un novato cuando se trata de Vaadin "del lado del servidor" frente al "lado del cliente".
➠ ¿Hay algún tipo de empaque que deba realizar? Actualmente tengo mis tres clases en mi proyecto Vaadin junto con elMyUI archivo fuente.
➠ ¿Me estoy perdiendo alguna otra pieza?
Ejecuté mi renderizador llamando al constructor sin argumentos:
this.entriesGrid
.addColumn( Entry::getStart )
.setCaption( "Start" )
.setRenderer( new InstantRenderer( ) )
;
Aquí están mis tres archivos enumerados anteriormente, tomados casi por completo del código fuente de Vaadin.
InstantRenderer/*
* By Basil Bourque. Taken almost entirely from source code published by Vaadin Ltd.
*
* --------
*
* Copyright 2000-2016 Vaadin Ltd.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.basil.timepiece;
import java.time.Instant;
import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;
import java.time.format.FormatStyle;
import java.util.Locale;
import elemental.json.JsonValue;
/**
* A renderer for presenting {@code Instant} objects.
*
* @author Vaadin Ltd
* @since 8.1
*/
public class InstantRenderer
extends com.vaadin.ui.renderers.AbstractRenderer< Object, Instant >
{
private DateTimeFormatter formatter;
private boolean getLocaleFromGrid;
private ZoneId zoneId = ZoneId.systemDefault(); // Basil Bourque.
/**
* Creates a new InstantRenderer.
* <p>
* The renderer is configured to render with the grid's locale it is
* attached to, with the format style being {@code FormatStyle.LONG} for the
* date and {@code FormatStyle.SHORT} for time, with an empty string as its
* null representation.
*
* @see <a href=
* "https://docs.oracle.com/javase/8/docs/api/java/time/format/FormatStyle.html#LONG">
* FormatStyle.LONG</a>
* @see <a href=
* "https://docs.oracle.com/javase/8/docs/api/java/time/format/FormatStyle.html#SHORT">
* FormatStyle.SHORT</a>
*/
public InstantRenderer ()
{
this( DateTimeFormatter.ofLocalizedDateTime( FormatStyle.LONG , FormatStyle.SHORT ) , "" );
getLocaleFromGrid = true;
}
/**
* Creates a new InstantRenderer.
* <p>
* The renderer is configured to render with the given formatter, with the
* empty string as its null representation.
*
* @param formatter the formatter to use, not {@code null}
* @throws IllegalArgumentException if formatter is null
*/
public InstantRenderer ( DateTimeFormatter formatter )
{
this( formatter , "" );
}
/**
* Creates a new InstantRenderer.
* <p>
* The renderer is configured to render with the given formatter.
*
* @param formatter the formatter to use, not {@code null}
* @param nullRepresentation the textual representation of the {@code null} value
* @throws IllegalArgumentException if formatter is null
*/
public InstantRenderer ( DateTimeFormatter formatter , String nullRepresentation )
{
super( Instant.class , nullRepresentation );
if ( formatter == null )
{
throw new IllegalArgumentException( "formatter may not be null" );
}
this.formatter = formatter;
}
/**
* Creates a new InstantRenderer.
* <p>
* The renderer is configured to render with the given string format, as
* displayed in the grid's locale it is attached to, with an empty string as
* its null representation.
*
* @param formatPattern the format pattern to format the date with, not {@code null}
* @throws IllegalArgumentException if format pattern is null
* @see <a href=
* "https://docs.oracle.com/javase/8/docs/api/java/time/format/DateTimeFormatter.html#patterns">
* Format Pattern Syntax</a>
*/
public InstantRenderer ( String formatPattern )
{
this( formatPattern , Locale.getDefault() );
getLocaleFromGrid = true;
}
/**
* Creates a new InstantRenderer.
* <p>
* The renderer is configured to render with the given string format, as
* displayed in the given locale, with an empty string as its null
* representation.
*
* @param formatPattern the format pattern to format the date with, not {@code null}
* @param locale the locale to use, not {@code null}
* @throws IllegalArgumentException if format pattern is null
* @throws IllegalArgumentException if locale is null
* @see <a href=
* "https://docs.oracle.com/javase/8/docs/api/java/time/format/DateTimeFormatter.html#patterns">
* Format Pattern Syntax</a>
*/
public InstantRenderer ( String formatPattern , Locale locale )
{
this( formatPattern , locale , "" );
}
/**
* Creates a new InstantRenderer.
* <p>
* The renderer is configured to render with the given string format, as
* displayed in the given locale.
*
* @param formatPattern the format pattern to format the date with, not {@code null}
* @param locale the locale to use, not {@code null}
* @param nullRepresentation the textual representation of the {@code null} value
* @throws IllegalArgumentException if format pattern is null
* @throws IllegalArgumentException if locale is null
* @see <a href=
* "https://docs.oracle.com/javase/8/docs/api/java/time/format/DateTimeFormatter.html#patterns">
* Format Pattern Syntax</a>
*/
public InstantRenderer ( String formatPattern , Locale locale , String nullRepresentation )
{
super( Instant.class , nullRepresentation );
if ( formatPattern == null )
{
throw new IllegalArgumentException( "format pattern may not be null" );
}
if ( locale == null )
{
throw new IllegalArgumentException( "locale may not be null" );
}
formatter = DateTimeFormatter.ofPattern( formatPattern , locale );
}
@Override
public JsonValue encode ( Instant value )
{
String dateString;
if ( value == null )
{
dateString = this.getNullRepresentation();
} else if ( this.getLocaleFromGrid )
{
if ( null == this.getParentGrid() )
{
throw new IllegalStateException(
"Could not find a locale to format with: "
+ "this renderer should either be attached to a grid "
+ "or constructed with locale information" );
}
ZonedDateTime zdt = value.atZone( this.zoneId ); // Basil Bourque.
Locale locale = this.getParentGrid().getLocale();
dateString = zdt.format( formatter.withLocale( locale ) );
} else
{
ZonedDateTime zdt = value.atZone( this.zoneId ); // Basil Bourque.
dateString = zdt.format( formatter );
}
return encode( dateString , String.class );
}
@Override
protected InstantRendererState getState ()
{
InstantRendererState s = ( InstantRendererState ) super.getState();
return s;
}
@Override
protected InstantRendererState getState ( boolean markAsDirty )
{
InstantRendererState s = ( InstantRendererState ) super.getState( markAsDirty );
return s;
}
}
InstantRendererConnector/*
* By Basil Bourque. Taken almost entirely from source code published by Vaadin Ltd.
*
* --------
*
* Copyright 2000-2016 Vaadin Ltd.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.basil.timepiece;
import com.vaadin.shared.ui.Connect;
/**
* A connector for InstantRenderer.
* <p>
* The server-side Renderer operates on {@code Instant}s, but the data is
* serialized as a string, and displayed as-is on the client side. This is to be
* able to support the server's locale.
*
* @author Vaadin Ltd
* @since 8.1
*/
@Connect( InstantRenderer.class )
public class InstantRendererConnector extends com.vaadin.client.connectors.grid.TextRendererConnector
{
@Override
public InstantRendererState getState ()
{
return ( InstantRendererState ) super.getState();
}
}
InstantRendererState/*
* By Basil Bourque. Taken almost entirely from source code published by Vaadin Ltd.
*
* --------
*
* Copyright 2000-2016 Vaadin Ltd.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.basil.timepiece;
/**
* Shared state of InstantRenderer.
*
* @author Vaadin Ltd
* @since 8.1
*/
public class InstantRendererState extends com.vaadin.shared.ui.grid.renderers.TextRendererState
{
// This code intentionally left blank.
}
He publicado miproyecto completo impulsado por Maven en BitBucket, todos los archivos necesarios para los renderizadores de columna paraInstant, OffsetDateTimeyZonedDateTime.
publiquéEdición 10208Implemente renderizadores de columna para Vaadin Grid para otros tipos java.time (Instant, OffsetDateTime, ZonedDateTime) para complementar los renderizadores LocalDate y LocalDateTime en Vaadin 8.1. en la página Vaadin Framework GitHub.