/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.apache.cocoon.components.treeprocessor.sitemap;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import org.apache.avalon.framework.component.ComponentManager;
import org.apache.avalon.framework.component.Composable;
import org.apache.avalon.framework.configuration.Configurable;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.cocoon.ProcessingException;
import org.apache.cocoon.components.flow.Interpreter;
import org.apache.cocoon.components.treeprocessor.AbstractProcessingNode;
import org.apache.cocoon.components.treeprocessor.InvokeContext;
import org.apache.cocoon.components.treeprocessor.variables.VariableResolver;
import org.apache.cocoon.components.treeprocessor.variables.VariableResolverFactory;
import org.apache.cocoon.environment.Environment;
import org.apache.cocoon.environment.Redirector;
import org.apache.cocoon.sitemap.PatternException;
/**
* Node handler for calling functions and resuming continuations in
* the control flow layer.
*
* @author <a href="mailto:ovidiu@apache.org">Ovidiu Predescu</a>
* @since March 13, 2002
* @version CVS $Id$
*/
public class CallFunctionNode extends AbstractProcessingNode implements Configurable, Composable {
protected List parameters;
protected VariableResolver functionName;
protected VariableResolver continuationId;
protected ComponentManager manager;
protected Interpreter interpreter;
public static List resolveList(List expressions, ComponentManager manager, InvokeContext context, Map objectModel)
throws PatternException {
int size;
if (expressions == null || (size = expressions.size()) == 0)
return Collections.EMPTY_LIST;
List result = new ArrayList(size);
for (int i = 0; i < size; i++) {
Interpreter.Argument arg = (Interpreter.Argument)expressions.get(i);
String value = VariableResolverFactory.getResolver(arg.value, manager).resolve(context, objectModel);
result.add(new Interpreter.Argument(arg.name, value));
}
return result;
}
public CallFunctionNode(VariableResolver functionName, VariableResolver continuationId) {
this.functionName = functionName;
this.continuationId = continuationId;
}
public void setInterpreter(Interpreter interp) throws Exception {
this.interpreter = interp;
}
/**
* Obtain the configuration specific to this node type and update
* the internal state.
*
* @param config a <code>Configuration</code> value
* @exception ConfigurationException if an error occurs
*/
public void configure(Configuration config) throws ConfigurationException {
//TODO (SW): Deprecate this in the future.
// It has be found to be bad practice to pass sitemap parameters
// as function arguments, as these are name-value pairs in the sitemap
// and positional arguments in the flowscript. If the user doesn't respect
// the argument order, this leads to difficult to solve bugs.
parameters = new ArrayList();
Configuration[] params = config.getChildren("parameter");
for (int i = 0; i < params.length; i++) {
Configuration param = params[i];
String name = param.getAttribute("name", null);
String value = param.getAttribute("value", null);
parameters.add(new Interpreter.Argument(name, value));
}
}
public void compose(ComponentManager manager) {
this.manager = manager;
}
public boolean invoke(Environment env, InvokeContext context) throws Exception {
List params = null;
// Resolve parameters
if (parameters != null) {
params = resolveList(parameters, manager, context, env.getObjectModel());
}
// Need redirector in any case
Redirector redirector = context.getRedirector();
// If the continuation id is not null, it takes precedence over
// the function call, so we invoke it here.
String continuation = continuationId.resolve(context, env.getObjectModel());
if (continuation != null && continuation.length() > 0) {
try {
interpreter.handleContinuation(continuation, params, redirector);
} catch(Exception e) {
throw ProcessingException.throwLocated("Sitemap: error calling continuation", e, getLocation());
}
if (!redirector.hasRedirected()) {
throw new ProcessingException("Sitemap: <map:call continuation> did not send a response", getLocation());
}
return true;
}
// We don't have a continuation id passed in <map:call>, so invoke
// the specified function
String name = functionName.resolve(context, env.getObjectModel());
if (name != null && name.length() > 0) {
try {
interpreter.callFunction(name, params, redirector);
} catch(Exception e) {
throw ProcessingException.throwLocated("Sitemap: error calling function '" + name + "'", e, getLocation());
}
if (!redirector.hasRedirected()) {
throw new ProcessingException("Sitemap: <map:call function> did not send a response", getLocation());
}
return true;
}
// Found neither continuation nor function to call
throw new ProcessingException("Sitemap: no function nor continuation given in <map:call function>", getLocation());
}
}