org.springframework.webflow.engine.support.AbstractFlowAttributeMapper Maven / Gradle / Ivy
/*
* Copyright 2002-2006 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.support;
import java.io.Serializable;
import org.springframework.binding.mapping.AttributeMapper;
import org.springframework.binding.mapping.MappingContext;
import org.springframework.webflow.core.collection.AttributeMap;
import org.springframework.webflow.core.collection.LocalAttributeMap;
import org.springframework.webflow.core.collection.MutableAttributeMap;
import org.springframework.webflow.engine.FlowAttributeMapper;
import org.springframework.webflow.execution.RequestContext;
/**
* Convenient base class for attribute mapper implementations. Encapsulates
* common attribute mapper workflow. Contains no state. Subclasses must override
* the {@link #getInputMapper()} and {@link #getOutputMapper()} methods to
* return the input mapper and output mapper, respectively.
*
* @author Keith Donald
*/
public abstract class AbstractFlowAttributeMapper implements FlowAttributeMapper, Serializable {
/**
* Returns the input mapper to use to map attributes of a parent flow
* {@link RequestContext} to a subflow input attribute {@link AttributeMap map}.
* @return the input mapper, or null if none
* @see #createFlowInput(RequestContext)
*/
protected abstract AttributeMapper getInputMapper();
/**
* Returns the output mapper to use to map attributes from a subflow output
* attribute map to the {@link RequestContext}.
* @return the output mapper, or null if none
* @see #mapFlowOutput(AttributeMap, RequestContext)
*/
protected abstract AttributeMapper getOutputMapper();
public MutableAttributeMap createFlowInput(RequestContext context) {
if (getInputMapper() != null) {
LocalAttributeMap input = new LocalAttributeMap();
// map from request context to input map
getInputMapper().map(context, input, getMappingContext(context));
return input;
}
else {
// an empty, but modifiable map
return new LocalAttributeMap();
}
}
public void mapFlowOutput(AttributeMap subflowOutput, RequestContext context) {
if (getOutputMapper() != null && subflowOutput != null) {
// map from subflow output map to request context
getOutputMapper().map(subflowOutput, context, getMappingContext(context));
}
}
/**
* Returns a map of contextual data available during mapping.
* This implementation just returns null.
*/
protected MappingContext getMappingContext(RequestContext context) {
return null;
}
}