org.springframework.web.reactive.result.method.annotation.InitBinderBindingContext Maven / Gradle / Ivy
/*
* Copyright 2002-2018 the original author or authors.
*
* 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 org.springframework.web.reactive.result.method.annotation;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.web.bind.annotation.InitBinder;
import org.springframework.web.bind.support.SessionStatus;
import org.springframework.web.bind.support.SimpleSessionStatus;
import org.springframework.web.bind.support.WebBindingInitializer;
import org.springframework.web.bind.support.WebExchangeDataBinder;
import org.springframework.web.reactive.BindingContext;
import org.springframework.web.reactive.HandlerResult;
import org.springframework.web.reactive.result.method.SyncInvocableHandlerMethod;
import org.springframework.web.server.ServerWebExchange;
import org.springframework.web.server.WebSession;
/**
* Extends {@link BindingContext} with {@code @InitBinder} method initialization.
*
* @author Rossen Stoyanchev
* @since 5.0
*/
class InitBinderBindingContext extends BindingContext {
private final List binderMethods;
/* Simple BindingContext to help with the invoking @InitBinder methods */
private final BindingContext binderMethodContext;
private final SessionStatus sessionStatus = new SimpleSessionStatus();
@Nullable
private Runnable saveModelOperation;
InitBinderBindingContext(@Nullable WebBindingInitializer initializer,
List binderMethods) {
super(initializer);
this.binderMethods = binderMethods;
this.binderMethodContext = new BindingContext(initializer);
}
/**
* Return the {@link SessionStatus} instance to use that can be used to
* signal that session processing is complete.
*/
public SessionStatus getSessionStatus() {
return this.sessionStatus;
}
@Override
protected WebExchangeDataBinder initDataBinder(WebExchangeDataBinder dataBinder,
ServerWebExchange exchange) {
this.binderMethods.stream()
.filter(binderMethod -> {
InitBinder ann = binderMethod.getMethodAnnotation(InitBinder.class);
Assert.state(ann != null, "No InitBinder annotation");
Collection names = Arrays.asList(ann.value());
return (names.isEmpty() || names.contains(dataBinder.getObjectName()));
})
.forEach(method -> invokeBinderMethod(dataBinder, exchange, method));
return dataBinder;
}
private void invokeBinderMethod(WebExchangeDataBinder dataBinder,
ServerWebExchange exchange, SyncInvocableHandlerMethod binderMethod) {
HandlerResult result = binderMethod.invokeForHandlerResult(
exchange, this.binderMethodContext, dataBinder);
if (result != null && result.getReturnValue() != null) {
throw new IllegalStateException(
"@InitBinder methods should return void: " + binderMethod);
}
// Should not happen (no Model argument resolution) ...
if (!this.binderMethodContext.getModel().asMap().isEmpty()) {
throw new IllegalStateException(
"@InitBinder methods should not add model attributes: " + binderMethod);
}
}
/**
* Provide the context required to apply {@link #saveModel()} after the
* controller method has been invoked.
*/
public void setSessionContext(SessionAttributesHandler attributesHandler, WebSession session) {
this.saveModelOperation = () -> {
if (getSessionStatus().isComplete()) {
attributesHandler.cleanupAttributes(session);
}
else {
attributesHandler.storeAttributes(session, getModel().asMap());
}
};
}
/**
* Save model attributes in the session based on a type-level declarations
* in an {@code @SessionAttributes} annotation.
*/
public void saveModel() {
if (this.saveModelOperation != null) {
this.saveModelOperation.run();
}
}
}