Support validation hints in FlowActionListener

Issue: SWF-1626

spring-faces/src/main/java/org/springframework/faces/webflow/FlowActionListener.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2004-2012 the original author or authors.
+ * 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.
@@ -34,18 +34,20 @@ import org.springframework.webflow.definition.TransitionDefinition;
 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 {
@@ -58,10 +60,21 @@ public class FlowActionListener implements ActionListener {
 
 	private final MessageCodesResolver messageCodesResolver = new WebFlowMessageCodesResolver();
 
+	private ValidationHintResolver validationHintResolver = new BeanValidationHintResolver();
+
+
 	public FlowActionListener(ActionListener delegate) {
 		this.delegate = delegate;
 	}
 
+	public void setValidationHintResolver(ValidationHintResolver validationHintResolver) {
+		this.validationHintResolver = validationHintResolver;
+	}
+
+	public ValidationHintResolver getValidationHintResolver() {
+		return validationHintResolver;
+	}
+
 	public void processAction(ActionEvent actionEvent) throws AbortProcessingException {
 		if (!JsfUtils.isFlowRequest()) {
 			this.delegate.processAction(actionEvent);
@@ -151,7 +164,11 @@ public class FlowActionListener implements ActionListener {
 	}
 
 	private void validate(RequestContext requestContext, Object model, String eventId) {
-		new ValidationHelper(model, requestContext, eventId, getModelExpression(requestContext).getExpressionString(),
+
-				null, this.messageCodesResolver, null).validate();
+		String modelName = getModelExpression(requestContext).getExpressionString();
+
+		new ValidationHelper(model, requestContext,
+				eventId, modelName, null, this.messageCodesResolver, null, this.validationHintResolver).validate();
 	}
+
 }

spring-webflow/src/main/java/org/springframework/webflow/mvc/view/AbstractMvcView.java

@@ -42,7 +42,6 @@ import org.springframework.binding.message.MessageBuilder;
 import org.springframework.binding.message.MessageResolver;
 import org.springframework.core.style.ToStringCreator;
 import org.springframework.util.Assert;
-import org.springframework.util.StringUtils;
 import org.springframework.validation.BindingResult;
 import org.springframework.validation.MessageCodesResolver;
 import org.springframework.validation.Validator;
@@ -53,7 +52,6 @@ import org.springframework.webflow.definition.TransitionDefinition;
 import org.springframework.webflow.engine.builder.BinderConfiguration;
 import org.springframework.webflow.engine.builder.BinderConfiguration.Binding;
 import org.springframework.webflow.execution.Event;
-import org.springframework.webflow.execution.FlowExecutionException;
 import org.springframework.webflow.execution.FlowExecutionKey;
 import org.springframework.webflow.execution.RequestContext;
 import org.springframework.webflow.execution.View;
@@ -593,39 +591,6 @@ public abstract class AbstractMvcView implements View {
 		return (Expression) requestContext.getCurrentState().getAttributes().get("model");
 	}
 
-	private Object[] getValidationHints(Object model, TransitionDefinition transition) {
-		Expression expr = null;
-		if (transition != null) {
-			expr = (Expression) transition.getAttributes().get("validationHints");
-		}
-		if (expr == null) {
-			expr = (Expression) requestContext.getCurrentState().getAttributes().get("validationHints");
-		}
-		if (expr == null) {
-			return null;
-		}
-		String flowId = requestContext.getActiveFlow().getId();
-		String stateId = requestContext.getCurrentState().getId();
-		try {
-			Object hintsValue = expr.getValue(requestContext);
-			if (hintsValue instanceof String) {
-				String[] hints = StringUtils.commaDelimitedListToStringArray((String) hintsValue);
-				return validationHintResolver.resolveValidationHints(model, flowId, stateId, hints);
-			}
-			else if (hintsValue instanceof Object[]) {
-				return (Object[]) hintsValue;
-			}
-			else {
-				throw new FlowExecutionException(flowId, stateId,
-						"Failed to resolve validation hints [" + hintsValue + "]");
-			}
-		}
-		catch (EvaluationException e) {
-			throw new FlowExecutionException(flowId, stateId,
-					"Failed to resolve validation hints expression [" + expr + "]", e);
-		}
-	}
-
 	private Object getEmptyValue(Class<?> fieldType) {
 		if (fieldType != null && boolean.class.equals(fieldType) || Boolean.class.equals(fieldType)) {
 			// Special handling of boolean property.
@@ -676,9 +641,8 @@ public abstract class AbstractMvcView implements View {
 			logger.debug("Validating model");
 		}
 		ValidationHelper helper = new ValidationHelper(model, requestContext, eventId, getModelExpression()
-				.getExpressionString(), expressionParser, messageCodesResolver, mappingResults);
+				.getExpressionString(), expressionParser, messageCodesResolver, mappingResults, validationHintResolver);
 		helper.setValidator(this.validator);
-		helper.setValidationHints(getValidationHints(model, transition));
 		helper.validate();
 	}
 

spring-webflow/src/main/java/org/springframework/webflow/validation/ValidationHelper.java

@@ -24,6 +24,8 @@ import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.springframework.aop.support.AopUtils;
 import org.springframework.beans.factory.BeanFactory;
+import org.springframework.binding.expression.EvaluationException;
+import org.springframework.binding.expression.Expression;
 import org.springframework.binding.expression.ExpressionParser;
 import org.springframework.binding.mapping.MappingResults;
 import org.springframework.binding.message.MessageContext;
@@ -37,6 +39,8 @@ import org.springframework.validation.Errors;
 import org.springframework.validation.MessageCodesResolver;
 import org.springframework.validation.SmartValidator;
 import org.springframework.validation.Validator;
+import org.springframework.webflow.definition.TransitionDefinition;
+import org.springframework.webflow.execution.FlowExecutionException;
 import org.springframework.webflow.execution.RequestContext;
 
 /**
@@ -86,8 +90,10 @@ public class ValidationHelper {
 	 * @param expressionParser the expression parser
 	 * @param mappingResults object mapping results
 	 */
-	public ValidationHelper(Object model, RequestContext requestContext, String eventId, String modelName,
+	public ValidationHelper(Object model, RequestContext requestContext, String eventId,
-			ExpressionParser expressionParser, MessageCodesResolver messageCodesResolver, MappingResults mappingResults) {
+			String modelName, ExpressionParser expressionParser, MessageCodesResolver messageCodesResolver,
+			MappingResults mappingResults, ValidationHintResolver hintResolver) {
+
 		Assert.notNull(model, "The model to validate is required");
 		Assert.notNull(requestContext, "The request context for the validator is required");
 		this.model = model;
@@ -97,6 +103,55 @@ public class ValidationHelper {
 		this.expressionParser = expressionParser;
 		this.messageCodesResolver = messageCodesResolver;
 		this.mappingResults = mappingResults;
+		this.validationHints = initValidationHints(model, requestContext, eventId, hintResolver);
+	}
+
+	/**
+	 * An alternative constructor that creates an instance of {@link BeanValidationHintResolver}.
+	 */
+	public ValidationHelper(Object model, RequestContext requestContext, String eventId,
+			String modelName, ExpressionParser expressionParser, MessageCodesResolver messageCodesResolver,
+			MappingResults mappingResults) {
+
+		this(model, requestContext, eventId, modelName, expressionParser,
+				messageCodesResolver, mappingResults, new BeanValidationHintResolver());
+	}
+
+
+	private static Object[] initValidationHints(Object model, RequestContext requestContext, String eventId,
+			ValidationHintResolver hintResolver) {
+
+		Expression expr = null;
+		TransitionDefinition transition = requestContext.getMatchingTransition(eventId);
+		if (transition != null) {
+			expr = (Expression) transition.getAttributes().get("validationHints");
+		}
+		if (expr == null) {
+			expr = (Expression) requestContext.getCurrentState().getAttributes().get("validationHints");
+		}
+		if (expr == null) {
+			return null;
+		}
+		String flowId = requestContext.getActiveFlow().getId();
+		String stateId = requestContext.getCurrentState().getId();
+		try {
+			Object hintsValue = expr.getValue(requestContext);
+			if (hintsValue instanceof String) {
+				String[] hints = StringUtils.commaDelimitedListToStringArray((String) hintsValue);
+				return hintResolver.resolveValidationHints(model, flowId, stateId, hints);
+			}
+			else if (hintsValue instanceof Object[]) {
+				return (Object[]) hintsValue;
+			}
+			else {
+				throw new FlowExecutionException(flowId, stateId,
+						"Failed to resolve validation hints [" + hintsValue + "]");
+			}
+		}
+		catch (EvaluationException e) {
+			throw new FlowExecutionException(flowId, stateId,
+					"Failed to resolve validation hints expression [" + expr + "]", e);
+		}
 	}
 
 	/**
@@ -107,7 +162,9 @@ public class ValidationHelper {
 	}
 
 	/**
-	 * Provide validation hints such as validation groups to use against a JSR-303 provider.
+	 * Provide validation hints (e.g. JSR-303 validation groups). Note that the constructor
+	 * automatically detects validation hints specified on a view state or a transition.
+	 * Therefore use of this method should not be needed.
 	 */
 	public void setValidationHints(Object[] validationHints) {
 		this.validationHints = validationHints;

spring-webflow/src/test/java/org/springframework/webflow/validation/ValidationHelperTests.java

@@ -17,6 +17,7 @@ package org.springframework.webflow.validation;
 
 import junit.framework.TestCase;
 
+import org.springframework.binding.expression.support.StaticExpression;
 import org.springframework.binding.message.MessageContext;
 import org.springframework.binding.validation.ValidationContext;
 import org.springframework.context.support.StaticApplicationContext;
@@ -25,7 +26,9 @@ import org.springframework.validation.Errors;
 import org.springframework.validation.SmartValidator;
 import org.springframework.webflow.engine.Flow;
 import org.springframework.webflow.engine.StubViewFactory;
+import org.springframework.webflow.engine.Transition;
 import org.springframework.webflow.engine.ViewState;
+import org.springframework.webflow.engine.support.DefaultTransitionCriteria;
 import org.springframework.webflow.test.MockRequestControlContext;
 
 /**
@@ -337,16 +340,54 @@ public class ValidationHelperTests extends TestCase {
 		assertTrue(validator.fallbackInvoked);
 	}
 
-	public void testSmartValidatorWithStateIdHint() {
+	public void testSmartValidatorWithClassHint() {
+		ViewState state = new ViewState(requestContext.getRootFlow(), "state2", new StubViewFactory());
+		state.getAttributes().put("validationHints", new StaticExpression(new Object[] { Model.State1.class }));
+		requestContext.setCurrentState(state);
+
 		LegacyModelValidator validator = new LegacyModelValidator();
 		ExtendedModel model = new ExtendedModel();
 		ValidationHelper helper = new ValidationHelper(model, requestContext, eventId, modelName, null, codesResolver, null);
 		helper.setValidator(validator);
-		helper.setValidationHints(new Object[] { Model.State1.class });
+
+		helper.validate();
+
+		assertTrue(validator.fallbackInvoked);
+		assertTrue(validator.hints.length > 0);
+		assertEquals(Model.State1.class, validator.hints[0]);
+	}
+
+	public void testSmartValidatorWithHintResolution() {
+		ViewState state = new ViewState(requestContext.getRootFlow(), "state2", new StubViewFactory());
+		state.getAttributes().put("validationHints", new StaticExpression("State1"));
+		requestContext.setCurrentState(state);
+
+		LegacyModelValidator validator = new LegacyModelValidator();
+		ExtendedModel model = new ExtendedModel();
+		ValidationHelper helper = new ValidationHelper(model, requestContext, eventId, modelName, null, codesResolver, null);
+		helper.setValidator(validator);
+
+		helper.validate();
+
+		assertTrue(validator.fallbackInvoked);
+		assertTrue(validator.hints.length > 0);
+		assertEquals(Model.State1.class, validator.hints[0]);
+	}
+
+	public void testSmartValidatorWithHintOnTransition() {
+		Transition transition = new Transition();
+		transition.setMatchingCriteria(new DefaultTransitionCriteria(new StaticExpression(eventId)));
+		transition.getAttributes().put("validationHints", new StaticExpression("State1"));
 
 		ViewState state = new ViewState(requestContext.getRootFlow(), "state2", new StubViewFactory());
+		state.getTransitionSet().add(transition);
 		requestContext.setCurrentState(state);
 
+		LegacyModelValidator validator = new LegacyModelValidator();
+		ExtendedModel model = new ExtendedModel();
+		ValidationHelper helper = new ValidationHelper(model, requestContext, eventId, modelName, null, codesResolver, null);
+		helper.setValidator(validator);
+
 		helper.validate();
 
 		assertTrue(validator.fallbackInvoked);
@@ -367,7 +408,7 @@ public class ValidationHelperTests extends TestCase {
 			fallbackInvoked = true;
 		}
 
-		private static class State1 {}
+		private static interface State1 {}
 	}
 
 	public static class ExtendedModel extends Model {