org.springframework.webflow.engine.support.FlowDefinitionRedirectSelector 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.util.HashMap;
import java.util.Map;
import org.springframework.binding.expression.Expression;
import org.springframework.util.StringUtils;
import org.springframework.webflow.engine.ViewSelector;
import org.springframework.webflow.execution.RequestContext;
import org.springframework.webflow.execution.ViewSelection;
import org.springframework.webflow.execution.support.FlowDefinitionRedirect;
/**
* Makes a {@link FlowDefinitionRedirect} selection when requested, calculating the
* flowDefinitionId and executionInput by
* evaluating an expression against the request context.
*
* @see org.springframework.webflow.execution.support.FlowDefinitionRedirect
*
* @author Keith Donald
*/
public class FlowDefinitionRedirectSelector implements ViewSelector {
/**
* The parsed flow expression, evaluatable to the string format:
* flowDefinitionId?param1Name=parmValue¶m2Name=paramValue.
*/
private Expression expression;
/**
* Creates a new launch flow redirect selector.
* @param expression the parsed flow redirect expression, evaluatable to the
* string format: flowDefinitionId?param1Name=parmValue¶m2Name=paramValue
*/
public FlowDefinitionRedirectSelector(Expression expression) {
this.expression = expression;
}
public boolean isEntrySelectionRenderable(RequestContext context) {
return true;
}
public ViewSelection makeEntrySelection(RequestContext context) {
String encodedRedirect = (String)expression.evaluate(context, null);
if (encodedRedirect == null) {
throw new IllegalStateException(
"Flow definition redirect expression evaluated to [null], the expression was " + expression);
}
// the encoded FlowDefinitionRedirect should look something like
// "flowDefinitionId?param0=value0¶m1=value1"
// now parse that and build a corresponding view selection
int index = encodedRedirect.indexOf('?');
String flowDefinitionId;
Map executionInput = null;
if (index != -1) {
flowDefinitionId = encodedRedirect.substring(0, index);
String[] parameters = StringUtils.delimitedListToStringArray(encodedRedirect.substring(index + 1), "&");
executionInput = new HashMap(parameters.length, 1);
for (int i = 0; i < parameters.length; i++) {
String nameAndValue = parameters[i];
index = nameAndValue.indexOf('=');
if (index != -1) {
executionInput.put(nameAndValue.substring(0, index), nameAndValue.substring(index + 1));
}
else {
executionInput.put(nameAndValue, "");
}
}
}
else {
flowDefinitionId = encodedRedirect;
}
if (!StringUtils.hasText(flowDefinitionId)) {
// equivalent to restart
flowDefinitionId = context.getFlowExecutionContext().getDefinition().getId();
}
return new FlowDefinitionRedirect(flowDefinitionId, executionInput);
}
public ViewSelection makeRefreshSelection(RequestContext context) {
return makeEntrySelection(context);
}
}