/*
* Copyright 2004-2014 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 java.util.ArrayList;
import java.util.List;
import javax.faces.application.NavigationHandler;
import javax.faces.component.ActionSource2;
import javax.faces.context.FacesContext;
import javax.faces.event.AbortProcessingException;
import javax.faces.event.ActionEvent;
import javax.faces.event.ActionListener;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.binding.expression.Expression;
import org.springframework.util.StringUtils;
import org.springframework.validation.MessageCodesResolver;
import org.springframework.validation.Validator;
import org.springframework.webflow.definition.TransitionDefinition;
import org.springframework.webflow.engine.builder.model.FlowModelFlowBuilder;
import org.springframework.webflow.execution.RequestContext;
import org.springframework.webflow.execution.RequestContextHolder;
import org.springframework.webflow.execution.View;
import org.springframework.webflow.validation.BeanValidationHintResolver;
import org.springframework.webflow.validation.ValidationHelper;
import org.springframework.webflow.validation.ValidationHintResolver;
import org.springframework.webflow.validation.WebFlowMessageCodesResolver;
/**
* The default {@link ActionListener} implementation to be used with Web Flow.
*
* This implementation bypasses the JSF {@link NavigationHandler} mechanism to instead let the event be handled directly
* by Web Flow.
* <p>
* Web Flow's model-level validation will be invoked here after an event has been detected if the event is not an
* immediate event.
*
* @author Jeremy Grelle
*/
public class FlowActionListener implements ActionListener {
private static final Log logger = LogFactory.getLog(FlowActionListener.class);
private static final String MESSAGES_ID = "messages";
private final ActionListener delegate;
private final MessageCodesResolver messageCodesResolver = new WebFlowMessageCodesResolver();
public FlowActionListener(ActionListener delegate) {
this.delegate = delegate;
}
public void processAction(ActionEvent actionEvent) throws AbortProcessingException {
if (!JsfUtils.isFlowRequest()) {
this.delegate.processAction(actionEvent);
return;
}
FacesContext context = FacesContext.getCurrentInstance();
ActionSource2 source = (ActionSource2) actionEvent.getSource();
String eventId = null;
if (source.getActionExpression() != null) {
if (logger.isDebugEnabled()) {
logger.debug("Invoking action " + source.getActionExpression());
}
eventId = (String) source.getActionExpression().invoke(context.getELContext(), null);
}
if (StringUtils.hasText(eventId)) {
if (logger.isDebugEnabled()) {
logger.debug("Event '" + eventId + "' detected");
}
if (source.isImmediate() || validateModel(context, eventId)) {
context.getExternalContext().getRequestMap().put(JsfView.EVENT_KEY, eventId);
}
} else {
logger.debug("No action event detected");
context.getExternalContext().getRequestMap().remove(JsfView.EVENT_KEY);
}
// tells JSF lifecycle that rendering should now happen and any subsequent phases should be skipped
// required in the case of this action listener firing immediately (immediate=true) before validation
context.renderResponse();
}
// internal helpers
private boolean validateModel(FacesContext facesContext, String eventId) {
boolean isValid = true;
RequestContext requestContext = RequestContextHolder.getRequestContext();
Object model = getModelObject(requestContext);
if (shouldValidate(requestContext, model, eventId)) {
validate(requestContext, model, eventId);
if (requestContext.getMessageContext().hasErrorMessages()) {
isValid = false;
if (requestContext.getExternalContext().isAjaxRequest()) {
List<String> fragments = new ArrayList<String>();
String formId = getModelExpression(requestContext).getExpressionString();
if (facesContext.getViewRoot().findComponent(formId) != null) {
fragments.add(formId);
}
if (facesContext.getViewRoot().findComponent(MESSAGES_ID) != null) {
fragments.add(MESSAGES_ID);
}
if (fragments.size() > 0) {
String[] fragmentsArray = new String[fragments.size()];
for (int i = 0; i < fragments.size(); i++) {
fragmentsArray[i] = fragments.get(i);
}
requestContext.getFlashScope().put(View.RENDER_FRAGMENTS_ATTRIBUTE, fragmentsArray);
}
}
}
}
return isValid;
}
private Object getModelObject(RequestContext requestContext) {
Expression model = getModelExpression(requestContext);
if (model != null) {
return model.getValue(requestContext);
} else {
return null;
}
}
private Expression getModelExpression(RequestContext requestContext) {
return (Expression) requestContext.getCurrentState().getAttributes().get("model");
}
private boolean shouldValidate(RequestContext requestContext, Object model, String eventId) {
if (model == null) {
return false;
}
TransitionDefinition transition = requestContext.getMatchingTransition(eventId);
if (transition != null) {
if (transition.getAttributes().contains("validate")) {
return transition.getAttributes().getBoolean("validate");
}
}
return true;
}
private void validate(RequestContext requestContext, Object model, String eventId) {
String modelName = getModelExpression(requestContext).getExpressionString();
String attr = FlowModelFlowBuilder.VALIDATOR_FLOW_ATTR;
Validator validator = (Validator) requestContext.getActiveFlow().getAttributes().get(attr);
ValidationHelper helper = new ValidationHelper(model, requestContext, eventId,
modelName, null, this.messageCodesResolver, null, getHintResolver(requestContext));
helper.setValidator(validator);
helper.validate();
}
private ValidationHintResolver getHintResolver(RequestContext requestContext) {
ValidationHintResolver hintResolver = (ValidationHintResolver) requestContext.getActiveFlow()
.getAttributes().get(FlowModelFlowBuilder.VALIDATION_HINT_RESOLVER_FLOW_ATTR);
return (hintResolver != null ? hintResolver : new BeanValidationHintResolver());
}
}