/* * 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.List; import org.springframework.lang.Nullable; import org.springframework.util.Assert; import org.springframework.util.ObjectUtils; 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<SyncInvocableHandlerMethod> binderMethods; private final BindingContext binderMethodContext; private final SessionStatus sessionStatus = new SimpleSessionStatus(); @Nullable private Runnable saveModelOperation; InitBinderBindingContext(@Nullable WebBindingInitializer initializer, List<SyncInvocableHandlerMethod> 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"); String[] names = ann.value(); return (ObjectUtils.isEmpty(names) || ObjectUtils.containsElement(names, 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 must not return a value (should be void): " + binderMethod); } // Should not happen (no Model argument resolution) ... if (!this.binderMethodContext.getModel().asMap().isEmpty()) { throw new IllegalStateException( "@InitBinder methods are not allowed to 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(); } } }