/*****************************************************************************
* Copyright (C) NanoContainer Organization. All rights reserved. *
* ------------------------------------------------------------------------- *
* The software in this package is published under the terms of the BSD *
* style license a copy of which has been included with this distribution in *
* the LICENSE.txt file. *
* *
* Original code by *
*****************************************************************************/
package org.nanocontainer.script.groovy;
import groovy.lang.*;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.net.URL;
import org.codehaus.groovy.control.CompilationFailedException;
import org.codehaus.groovy.runtime.InvokerHelper;
import org.nanocontainer.NanoContainer;
import org.nanocontainer.script.NanoContainerMarkupException;
import org.nanocontainer.script.ScriptedContainerBuilder;
import org.picocontainer.PicoContainer;
/**
* {@inheritDoc}
* The groovy script has to return an instance of {@link NanoContainer}.
* There is an implicit variable named "parent" that may contain a reference to a parent
* container. It is recommended to use this as a constructor argument to the instantiated
* NanoPicoContainer.
*
* @author Paul Hammant
* @author Aslak Hellesøy
* @author Mauro Talevi
* @version $Revision: 2791 $
*/
public class GroovyContainerBuilder extends ScriptedContainerBuilder {
private Script groovyScript;
public GroovyContainerBuilder(final Reader script, ClassLoader classLoader) {
super(script, classLoader);
}
public GroovyContainerBuilder(final URL script, ClassLoader classLoader) {
super(script, classLoader);
}
// TODO: This should really return NanoContainer using a nano variable in the script. --Aslak
protected PicoContainer createContainerFromScript(PicoContainer parentContainer, Object assemblyScope) {
if (groovyScript == null) {
createGroovyScript();
}
Binding binding = new Binding();
binding.setVariable("parent", parentContainer);
binding.setVariable("builder", createGroovyNodeBuilder());
binding.setVariable("assemblyScope", assemblyScope);
handleBinding(binding);
groovyScript.setBinding(binding);
// both returning something or defining the variable is ok.
Object result = groovyScript.run();
Object picoVariable;
try {
picoVariable = binding.getVariable("pico");
} catch (MissingPropertyException e) {
picoVariable = result;
}
if (picoVariable instanceof PicoContainer) {
return (PicoContainer) picoVariable;
} else if (picoVariable instanceof NanoContainer) {
return ((NanoContainer) picoVariable).getPico();
} else {
throw new NanoContainerMarkupException("Bad type for pico:" + picoVariable.getClass().getName());
}
}
/**
* Allows customization of the groovy node builder in descendants.
* @return CustomGroovyNodeBuilder
*/
protected GroovyObject createGroovyNodeBuilder() {
return new CustomGroovyNodeBuilder();
}
/**
* This allows children of this class to add to the default binding.
* Might want to add similar or a more generic implementation of this
* method to support the other scripting languages.
*/
protected void handleBinding(Binding binding) {
// does nothing but adds flexibility for children
}
private void createGroovyScript() {
try {
GroovyClassLoader loader = new GroovyClassLoader(getClassLoader());
InputStream scriptIs = getScriptInputStream();
GroovyCodeSource groovyCodeSource = new GroovyCodeSource(scriptIs,"nanocontainer.groovy","groovyGeneratedForNanoContainer");
Class scriptClass = loader.parseClass(groovyCodeSource);
groovyScript = InvokerHelper.createScript(scriptClass, null);
} catch (CompilationFailedException e) {
throw new GroovyCompilationException("Compilation Failed '" + e.getMessage() + "'", e);
} catch (IOException e) {
throw new NanoContainerMarkupException(e);
}
}
}