MvcViewFactoryCreator.java
/*
* 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
*
* https://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.webflow.mvc.builder;
import java.util.List;
import org.springframework.beans.BeanWrapper;
import org.springframework.binding.convert.ConversionService;
import org.springframework.binding.expression.Expression;
import org.springframework.binding.expression.ExpressionParser;
import org.springframework.binding.expression.beanwrapper.BeanWrapperExpressionParser;
import org.springframework.util.StringUtils;
import org.springframework.validation.DefaultMessageCodesResolver;
import org.springframework.validation.MessageCodesResolver;
import org.springframework.validation.Validator;
import org.springframework.web.servlet.View;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.webflow.engine.builder.BinderConfiguration;
import org.springframework.webflow.engine.builder.ViewFactoryCreator;
import org.springframework.webflow.execution.ViewFactory;
import org.springframework.webflow.mvc.servlet.ServletMvcViewFactory;
import org.springframework.webflow.mvc.view.AbstractMvcViewFactory;
import org.springframework.webflow.mvc.view.FlowViewResolver;
import org.springframework.webflow.validation.ValidationHintResolver;
import org.springframework.webflow.validation.WebFlowMessageCodesResolver;
/**
* Returns {@link ViewFactory view factories} that create native Spring MVC-based views. Used by a FlowBuilder to
* configure a flow's view states with Spring MVC-based view factories.
* <p>
* By default, this implementation creates view factories that resolve their views by loading flow-relative resources,
* such as .jsp templates located in a flow working directory. This class also supports rendering views resolved by
* pre-existing Spring MVC {@link ViewResolver view resolvers}.
*
* @see ServletMvcViewFactory
* @see FlowResourceFlowViewResolver
* @see DelegatingFlowViewResolver
*
* @author Keith Donald
* @author Scott Andrews
*/
public class MvcViewFactoryCreator implements ViewFactoryCreator {
private FlowViewResolver flowViewResolver = new FlowResourceFlowViewResolver();
private boolean useSpringBeanBinding;
private String eventIdParameterName;
private String fieldMarkerPrefix;
private MessageCodesResolver messageCodesResolver = new WebFlowMessageCodesResolver();
/**
* Create a new Spring MVC View Factory Creator.
* @see #setDefaultViewSuffix(String)
* @see #setEventIdParameterName(String)
* @see #setFieldMarkerPrefix(String)
* @see #setUseSpringBeanBinding(boolean)
* @see #setFlowViewResolver(FlowViewResolver)
* @see #setViewResolvers(List)
* @see #setMessageCodesResolver(MessageCodesResolver)
*/
public MvcViewFactoryCreator() {
}
/**
* Configure an {@link FlowResourceFlowViewResolver} capable of resolving view resources by applying the specified
* default resource suffix. Default is .jsp.
* @param defaultViewSuffix the default view suffix
*/
public void setDefaultViewSuffix(String defaultViewSuffix) {
FlowResourceFlowViewResolver internalResourceResolver = new FlowResourceFlowViewResolver();
internalResourceResolver.setDefaultViewSuffix(defaultViewSuffix);
this.flowViewResolver = internalResourceResolver;
}
/**
* Sets the name of the request parameter to use to lookup user events signaled by views created in this factory. If
* not specified, the default is <code>_eventId</code>
* @param eventIdParameterName the event id parameter name
*/
public void setEventIdParameterName(String eventIdParameterName) {
this.eventIdParameterName = eventIdParameterName;
}
/**
* Specify a prefix that can be used for parameters that mark potentially empty fields, having "prefix + field" as
* name. Such a marker parameter is checked by existence: You can send any value for it, for example "visible". This
* is particularly useful for HTML checkboxes and select options.
* <p>
* Default is "_", for "_FIELD" parameters (e.g. "_subscribeToNewsletter"). Set this to null if you want to turn off
* the empty field check completely.
* <p>
* HTML checkboxes only send a value when they're checked, so it is not possible to detect that a formerly checked
* box has just been unchecked, at least not with standard HTML means.
* <p>
* This auto-reset mechanism addresses this deficiency, provided that a marker parameter is sent for each checkbox
* field, like "_subscribeToNewsletter" for a "subscribeToNewsletter" field. As the marker parameter is sent in any
* case, the data binder can detect an empty field and automatically reset its value.
*/
public void setFieldMarkerPrefix(String fieldMarkerPrefix) {
this.fieldMarkerPrefix = fieldMarkerPrefix;
}
/**
* Sets whether to use data binding with Spring's {@link BeanWrapper} should be enabled. Set to 'true' to enable.
* 'false', disabled, is the default. With this enabled, the same binding system used by Spring MVC 2.x is also used
* in a Web Flow environment.
* @param useSpringBeanBinding the Spring bean binding flag
*/
public void setUseSpringBeanBinding(boolean useSpringBeanBinding) {
this.useSpringBeanBinding = useSpringBeanBinding;
}
/**
* Set to fully customize how the flow system resolves Spring MVC {@link View} objects.
* @param flowViewResolver the flow view resolver
*/
public void setFlowViewResolver(FlowViewResolver flowViewResolver) {
this.flowViewResolver = flowViewResolver;
}
/**
* Sets the chain of Spring MVC {@link ViewResolver view resolvers} to delegate to resolve views selected by flows.
* Allows for reuse of existing View Resolvers configured in a Spring application context. If multiple resolvers are
* to be used, the resolvers should be ordered in the manner they should be applied.
* @param viewResolvers the view resolver list
*/
public void setViewResolvers(List<ViewResolver> viewResolvers) {
this.flowViewResolver = new DelegatingFlowViewResolver(viewResolvers);
}
/**
* Sets the message codes resolver strategy to use to resolve bind and validation error message codes. If not set,
* {@link WebFlowMessageCodesResolver} is the default. Plug in a {@link DefaultMessageCodesResolver} to resolve
* message codes consistently between Spring MVC Controllers and Web Flow.
* @param messageCodesResolver the message codes resolver
*/
public void setMessageCodesResolver(MessageCodesResolver messageCodesResolver) {
this.messageCodesResolver = messageCodesResolver;
}
public ViewFactory createViewFactory(Expression viewId, ExpressionParser expressionParser,
ConversionService conversionService, BinderConfiguration binderConfiguration,
Validator validator, ValidationHintResolver validationHintResolver) {
if (useSpringBeanBinding) {
expressionParser = new BeanWrapperExpressionParser(conversionService);
}
AbstractMvcViewFactory viewFactory = createMvcViewFactory(viewId, expressionParser, conversionService,
binderConfiguration);
if (StringUtils.hasText(eventIdParameterName)) {
viewFactory.setEventIdParameterName(eventIdParameterName);
}
if (StringUtils.hasText(fieldMarkerPrefix)) {
viewFactory.setFieldMarkerPrefix(fieldMarkerPrefix);
}
viewFactory.setValidator(validator);
viewFactory.setValidationHintResolver(validationHintResolver);
return viewFactory;
}
/**
* Creates a concrete instance of an AbstractMvcViewFactory.
*/
protected AbstractMvcViewFactory createMvcViewFactory(Expression viewId, ExpressionParser expressionParser,
ConversionService conversionService, BinderConfiguration binderConfiguration) {
return new ServletMvcViewFactory(viewId, flowViewResolver, expressionParser, conversionService,
binderConfiguration, messageCodesResolver);
}
public String getViewIdByConvention(String viewStateId) {
return flowViewResolver.getViewIdByConvention(viewStateId);
}
}