// Copyright 2004, 2005 The Apache Software Foundation
//
// 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.apache.tapestry.html;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import org.apache.hivemind.ApplicationRuntimeException;
import org.apache.hivemind.Resource;
import org.apache.tapestry.AbstractComponent;
import org.apache.tapestry.IBinding;
import org.apache.tapestry.IEngine;
import org.apache.tapestry.IMarkupWriter;
import org.apache.tapestry.IRequestCycle;
import org.apache.tapestry.IScript;
import org.apache.tapestry.PageRenderSupport;
import org.apache.tapestry.Tapestry;
import org.apache.tapestry.TapestryUtils;
import org.apache.tapestry.engine.IScriptSource;
/**
* Works with the {@link Body}component to add a script (and perhaps some initialization) to the
* HTML response. [ <a href="../../../../../ComponentReference/Script.html">Component Reference
* </a>]
*
* @author Howard Lewis Ship
*/
public abstract class Script extends AbstractComponent
{
private Map _baseSymbols;
/**
* A Map of input and output symbols visible to the body of the Script.
*
* @since 2.2
*/
private Map _symbols;
/**
* Constructs the symbols {@link Map}. This starts with the contents of the symbols parameter
* (if specified) to which is added any informal parameters. If both a symbols parameter and
* informal parameters are bound, then a copy of the symbols parameter's value is made (that is,
* the {@link Map}provided by the symbols parameter is read, but not modified).
*/
private Map getInputSymbols()
{
Map result = new HashMap();
if (_baseSymbols != null)
result.putAll(_baseSymbols);
// Now, iterate through all the binding names (which includes both
// formal and informal parmeters). Skip the formal ones and
// access the informal ones.
Iterator i = getBindingNames().iterator();
while (i.hasNext())
{
String bindingName = (String) i.next();
// Skip formal parameters
if (getSpecification().getParameter(bindingName) != null)
continue;
IBinding binding = getBinding(bindingName);
Object value = binding.getObject();
result.put(bindingName, value);
}
return result;
}
/**
* Gets the {@link IScript}for the correct script.
*/
private IScript getParsedScript(IRequestCycle cycle)
{
String scriptPath = getScriptPath();
if (scriptPath == null)
throw Tapestry.createRequiredParameterException(this, "scriptPath");
IEngine engine = cycle.getEngine();
IScriptSource source = engine.getScriptSource();
// If the script path is relative, it should be relative to the Script component's
// container (i.e., relative to a page in the application).
Resource rootLocation = getContainer().getSpecification().getSpecificationLocation();
Resource scriptLocation = rootLocation.getRelativeResource(scriptPath);
try
{
return source.getScript(scriptLocation);
}
catch (RuntimeException ex)
{
throw new ApplicationRuntimeException(ex.getMessage(), this, null, ex);
}
}
protected void renderComponent(IMarkupWriter writer, IRequestCycle cycle)
{
if (!cycle.isRewinding())
{
PageRenderSupport pageRenderSupport = TapestryUtils.getPageRenderSupport(cycle, this);
_symbols = getInputSymbols();
getParsedScript(cycle).execute(cycle, pageRenderSupport, _symbols);
}
// Render the body of the Script;
renderBody(writer, cycle);
}
public abstract String getScriptPath();
public Map getBaseSymbols()
{
return _baseSymbols;
}
public void setBaseSymbols(Map baseSymbols)
{
_baseSymbols = baseSymbols;
}
/**
* Returns the complete set of symbols (input and output) from the script execution. This is
* visible to the body of the Script, but is cleared after the Script finishes rendering.
*
* @since 2.2
*/
public Map getSymbols()
{
return _symbols;
}
protected void cleanupAfterRender(IRequestCycle cycle)
{
_symbols = null;
super.cleanupAfterRender(cycle);
}
}