Java tutorial
/* * Copyright 2004-2012 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.faces.webflow; import static org.springframework.faces.webflow.JsfRuntimeInformation.isPortletRequest; import java.util.Iterator; import javax.el.ValueExpression; import javax.faces.application.ViewHandler; import javax.faces.component.EditableValueHolder; import javax.faces.component.UIComponent; import javax.faces.component.UIViewRoot; import javax.faces.component.visit.VisitContext; import javax.faces.context.FacesContext; import javax.faces.event.AbortProcessingException; import javax.faces.event.ExceptionQueuedEvent; import javax.faces.event.ExceptionQueuedEventContext; import javax.faces.event.PhaseId; import javax.faces.lifecycle.Lifecycle; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.springframework.binding.expression.Expression; import org.springframework.util.Assert; import org.springframework.webflow.execution.RequestContext; import org.springframework.webflow.execution.View; import org.springframework.webflow.execution.ViewFactory; /** * JSF-specific {@link ViewFactory} implementation. * <p> * This factory is responsible for performing the duties of the RESTORE_VIEW phase of the JSF lifecycle. * * @author Jeremy Grelle * @author Phillip Webb */ public class JsfViewFactory implements ViewFactory { private static final Log logger = LogFactory.getLog(JsfViewFactory.class); private final Expression viewIdExpression; private final Lifecycle lifecycle; public JsfViewFactory(Expression viewIdExpression, Lifecycle lifecycle) { this.viewIdExpression = viewIdExpression; this.lifecycle = lifecycle; } /** * Executes the RESTORE_VIEW phase of the JSF lifecycle at the beginning of a request, and creates the next view to * be rendered in the case of an executing transition. */ public View getView(RequestContext context) { FacesContext facesContext = FlowFacesContext.getCurrentInstance(); Assert.state(facesContext != null, "FacesContext has not been initialized within the current Web Flow request." + " Check the configuration for your <webflow:flow-executor>." + " For JSF you will need FlowFacesContextLifecycleListener configured as one of its flow execution listeners."); facesContext.setCurrentPhaseId(PhaseId.RESTORE_VIEW); // only publish a RESTORE_VIEW event if this is the first phase of the lifecycle // this won't be true when this method is called after a transition from one view-state to another boolean notifyPhaseListeners = !facesContext.getRenderResponse(); if (notifyPhaseListeners) { JsfUtils.notifyBeforeListeners(PhaseId.RESTORE_VIEW, this.lifecycle, facesContext); } UIViewRoot viewRoot = getViewRoot(context, facesContext); facesContext.setViewRoot(viewRoot); publishPostRestoreStateEvent(facesContext); if (notifyPhaseListeners) { JsfUtils.notifyAfterListeners(PhaseId.RESTORE_VIEW, this.lifecycle, facesContext); } return new JsfView(viewRoot, this.lifecycle, context); } private UIViewRoot getViewRoot(RequestContext context, FacesContext facesContext) { ViewHandler viewHandler = getViewHandler(facesContext); String viewName = (String) this.viewIdExpression.getValue(context); if (viewAlreadySet(facesContext, viewName)) { return getViewRootForAlreadySetView(context, facesContext); } if (context.inViewState()) { return getViewStateViewRoot(context, facesContext, viewHandler, viewName); } return getTransientViewRoot(context, facesContext, viewHandler, viewName); } private ViewHandler getViewHandler(FacesContext facesContext) { ViewHandler viewHandler = facesContext.getApplication().getViewHandler(); if (!isPortletRequest(facesContext)) { viewHandler.initView(facesContext); } return viewHandler; } private boolean viewAlreadySet(FacesContext facesContext, String viewName) { // the corner case where a before RESTORE_VIEW PhaseListener has handled setting the UIViewRoot return (facesContext.getViewRoot() != null && facesContext.getViewRoot().getViewId().equals(viewName)); } private UIViewRoot getViewRootForAlreadySetView(RequestContext context, FacesContext facesContext) { if (logger.isDebugEnabled()) { logger.debug("Existing view root found with id '" + facesContext.getViewRoot().getId() + "'"); } UIViewRoot viewRoot = facesContext.getViewRoot(); viewRoot.setLocale(context.getExternalContext().getLocale()); processTree(facesContext, viewRoot); return viewRoot; } private UIViewRoot getViewStateViewRoot(RequestContext context, FacesContext facesContext, ViewHandler viewHandler, String viewName) { UIViewRoot viewRoot = viewHandler.restoreView(facesContext, viewName); if (viewRoot != null) { if (logger.isDebugEnabled()) { logger.debug("UIViewRoot restored for '" + viewName + "'"); } processTree(facesContext, viewRoot); } else { if (logger.isDebugEnabled()) { logger.debug("Creating UIViewRoot from '" + viewName + "'"); } viewRoot = viewHandler.createView(facesContext, viewName); } return viewRoot; } private UIViewRoot getTransientViewRoot(RequestContext context, FacesContext facesContext, ViewHandler viewHandler, String viewName) { if (logger.isDebugEnabled()) { logger.debug("Creating transient UIViewRoot from '" + viewName + "'"); } UIViewRoot viewRoot = viewHandler.createView(facesContext, viewName); viewRoot.setTransient(true); return viewRoot; } /** * Walk the component tree to perform any required per-component operations. * * @param context * @param component */ private void processTree(FacesContext context, UIComponent component) { // Only resetting the valid flag in the RESTORE_VIEW phase, // not during RENDER_RESPONSE if (!context.getRenderResponse() && component instanceof EditableValueHolder) { ((EditableValueHolder) component).setValid(true); } ValueExpression binding = component.getValueExpression("binding"); if (binding != null) { binding.setValue(context.getELContext(), component); } Iterator<UIComponent> it = component.getFacetsAndChildren(); while (it.hasNext()) { processTree(context, it.next()); } } private void publishPostRestoreStateEvent(FacesContext facesContext) { try { facesContext.getViewRoot().visitTree(VisitContext.createVisitContext(facesContext), new PostRestoreStateEventVisitCallback()); } catch (AbortProcessingException e) { facesContext.getApplication().publishEvent(facesContext, ExceptionQueuedEvent.class, new ExceptionQueuedEventContext(facesContext, e, null, facesContext.getCurrentPhaseId())); } } }