/*
* 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.webflow.engine.builder.support;
import org.springframework.binding.convert.ConversionException;
import org.springframework.binding.convert.ConversionExecutionException;
import org.springframework.binding.convert.ConversionExecutor;
import org.springframework.binding.convert.ConversionExecutorNotFoundException;
import org.springframework.binding.convert.ConversionService;
import org.springframework.binding.convert.service.GenericConversionService;
import org.springframework.binding.expression.ExpressionParser;
import org.springframework.context.ApplicationContext;
import org.springframework.util.Assert;
import org.springframework.validation.Validator;
import org.springframework.webflow.core.collection.AttributeMap;
import org.springframework.webflow.core.collection.CollectionUtils;
import org.springframework.webflow.definition.registry.FlowDefinitionLocator;
import org.springframework.webflow.engine.builder.FlowArtifactFactory;
import org.springframework.webflow.engine.builder.FlowBuilderContext;
import org.springframework.webflow.engine.builder.ViewFactoryCreator;
import org.springframework.webflow.validation.ValidationHintResolver;
/**
* Generic implementation of a flow builder context, suitable for use by most flow assembly systems.
* @author Keith Donald
*/
public class FlowBuilderContextImpl implements FlowBuilderContext {
private String flowId;
private AttributeMap<Object> flowAttributes;
private FlowDefinitionLocator flowDefinitionLocator;
private FlowBuilderServices flowBuilderServices;
private ConversionService conversionService;
/**
* Creates a new flow builder context.
* @param flowId the id to assign the flow being built
* @param flowAttributes attributes to assign the flow being built
* @param flowDefinitionLocator a locator to find dependent subflows
* @param flowBuilderServices a parameter object providing access to additional services needed by the flow builder
*/
public FlowBuilderContextImpl(String flowId, AttributeMap<Object> flowAttributes,
FlowDefinitionLocator flowDefinitionLocator, FlowBuilderServices flowBuilderServices) {
Assert.hasText(flowId, "The flow id is required");
Assert.notNull(flowDefinitionLocator, "The flow definition locator is required");
Assert.notNull(flowBuilderServices, "The flow builder services holder is required");
this.flowId = flowId;
initFlowAttributes(flowAttributes);
this.flowDefinitionLocator = flowDefinitionLocator;
this.flowBuilderServices = flowBuilderServices;
this.conversionService = createConversionService();
}
public FlowBuilderServices getFlowBuilderServices() {
return flowBuilderServices;
}
// implementing flow builder context
public String getFlowId() {
return flowId;
}
public AttributeMap<Object> getFlowAttributes() {
return flowAttributes;
}
public FlowArtifactFactory getFlowArtifactFactory() {
return flowBuilderServices.getFlowArtifactFactory();
}
public FlowDefinitionLocator getFlowDefinitionLocator() {
return flowDefinitionLocator;
}
public ConversionService getConversionService() {
return conversionService;
}
public ViewFactoryCreator getViewFactoryCreator() {
return flowBuilderServices.getViewFactoryCreator();
}
public ExpressionParser getExpressionParser() {
return flowBuilderServices.getExpressionParser();
}
public ApplicationContext getApplicationContext() {
return flowBuilderServices.getApplicationContext();
}
public Validator getValidator() {
return flowBuilderServices.getValidator();
}
public ValidationHintResolver getValidationHintResolver() {
return flowBuilderServices.getValidationHintResolver();
}
/**
* Factory method that creates the conversion service the flow builder will use. Subclasses may override. The
* default implementation registers Web Flow-specific converters thought to be useful for most builder
* implementations, setting the externally-provided builder services conversion service as its parent.
* @return the flow builder conversion service
*/
protected ConversionService createConversionService() {
GenericConversionService service = new GenericConversionService(getFlowBuilderServices().getConversionService()
.getDelegateConversionService());
service.addConverter(new TextToTransitionCriteria(this));
service.addConverter(new TextToTargetStateResolver(this));
service.setParent(new ParentConversionServiceProxy());
return service;
}
private void initFlowAttributes(AttributeMap<Object> flowAttributes) {
if (flowAttributes != null) {
this.flowAttributes = flowAttributes;
} else {
this.flowAttributes = CollectionUtils.EMPTY_ATTRIBUTE_MAP;
}
}
/**
* A little proxy that refreshes the externally configured conversion service reference on each invocation.
*/
private class ParentConversionServiceProxy implements ConversionService {
public Object executeConversion(Object source, Class<?> targetClass) throws ConversionException {
return getFlowBuilderServices().getConversionService().executeConversion(source, targetClass);
}
public Object executeConversion(String converterId, Object source, Class<?> targetClass) {
return getFlowBuilderServices().getConversionService().executeConversion(converterId, source, targetClass);
}
public ConversionExecutor getConversionExecutor(Class<?> sourceClass, Class<?> targetClass)
throws ConversionExecutionException {
return getFlowBuilderServices().getConversionService().getConversionExecutor(sourceClass, targetClass);
}
public ConversionExecutor getConversionExecutor(String id, Class<?> sourceClass, Class<?> targetClass)
throws ConversionExecutorNotFoundException {
return getFlowBuilderServices().getConversionService().getConversionExecutor(id, sourceClass, targetClass);
}
public Class<?> getClassForAlias(String name) {
return getFlowBuilderServices().getConversionService().getClassForAlias(name);
}
public org.springframework.core.convert.ConversionService getDelegateConversionService() {
return getFlowBuilderServices().getConversionService().getDelegateConversionService();
}
}
}