package org.apache.velocity.tools.view.tools;
/*
* 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.
*/
import java.util.Arrays;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import javax.servlet.ServletContext;
import org.apache.velocity.context.AbstractContext;
import org.apache.velocity.context.Context;
import org.apache.velocity.tools.generic.ValueParser;
import org.apache.velocity.tools.view.context.ChainedContext;
import org.apache.velocity.tools.view.context.ViewContext;
/**
* <p>View tool for convenient access to {@link ViewContext} data and
* meta-data.</p>
* <p><pre>
* Template example(s):
* #foreach( $key in $context.keys )
* $key = $context.get($key)
* #end
*
* Toolbox configuration:
* <tool>
* <key>context</key>
* <scope>request</scope>
* <class>org.apache.velocity.tools.view.tools.ContextTool</class>
* </tool>
* </pre></p>
*
* <p>This class is only designed for use as a request-scope VelocityView tool.</p>
*
* @author Nathan Bubna
* @since VelocityTools 1.3
* @version $Id: ContextTool.java 385122 2006-03-11 18:37:42Z nbubna $
*/
public class ContextTool
{
/**
* The key used for specifying whether to hide keys with '.' in them.
*/
public static final String SAFE_MODE_KEY = "safe-mode";
protected ViewContext context;
protected Map toolbox;
protected HttpServletRequest request;
protected HttpSession session;
protected ServletContext application;
private boolean safeMode = true;
/**
* Looks for a safe-mode configuration setting. By default,
* safe-mode is true and thus keys with '.' in them are hidden.
*/
public void configure(Map params)
{
if (params != null)
{
ValueParser parser = new ValueParser(params);
safeMode = parser.getBoolean(SAFE_MODE_KEY, true);
}
}
/**
* Initializes this instance for the current request.
*
* @param obj the ViewContext of the current request
*/
public void init(Object obj)
{
this.context = (ViewContext)obj;
this.request = context.getRequest();
this.session = request.getSession(false);
this.application = context.getServletContext();
}
/**
* Returns the context being analyzed by this tool.
*/
public ViewContext getThis()
{
return this.context;
}
/**
* <p>Returns a read-only view of the toolbox {@link Map}
* for this context.</p>
* @return an unmodifiable version of the toolbox for this request
* or {@code null} if there is none
*/
public Map getToolbox()
{
if (this.toolbox == null && this.context instanceof ChainedContext)
{
this.toolbox = ((ChainedContext)context).getToolbox();
}
return this.toolbox;
}
/**
* <p>Return a {@link Set} of the available reference keys in the current
* context.</p>
*/
public Set getKeys()
{
Set keys = new HashSet();
// get the tool keys, if there is a toolbox
Map tools = getToolbox();
if (tools != null)
{
keys.addAll(tools.keySet());
}
// recurse down the velocity context collecting keys
Context velctx = this.context.getVelocityContext();
while (velctx != null)
{
Object[] ctxKeys = velctx.getKeys();
keys.addAll(Arrays.asList(ctxKeys));
if (velctx instanceof AbstractContext)
{
velctx = ((AbstractContext)velctx).getChainedContext();
}
else
{
velctx = null;
}
}
// get request attribute keys
Enumeration e = request.getAttributeNames();
while (e.hasMoreElements())
{
keys.add(e.nextElement());
}
// get session attribute keys if we have a session
if (session != null)
{
e = session.getAttributeNames();
while (e.hasMoreElements())
{
keys.add(e.nextElement());
}
}
// get request attribute keys
e = application.getAttributeNames();
while (e.hasMoreElements())
{
keys.add(e.nextElement());
}
// if we're in safe mode, remove keys that contain '.'
if (safeMode)
{
for (Iterator i = keys.iterator(); i.hasNext(); )
{
String key = String.valueOf(i.next());
if (key.indexOf('.') >= 0)
{
i.remove();
}
}
}
// return the key set
return keys;
}
/**
* <p>Return a {@link Set} of the available values in the current
* context.</p>
*/
public Set getValues()
{
//TODO: this could be a lot more efficient
Set keys = getKeys();
Set values = new HashSet(keys.size());
for (Iterator i = keys.iterator(); i.hasNext(); )
{
String key = String.valueOf(i.next());
values.add(this.context.getVelocityContext().get(key));
}
return values;
}
/**
* <p>Returns {@code true} if the context contains a value for the specified
* reference name (aka context key).</p>
*/
public boolean contains(Object refName)
{
return (get(refName) != null);
}
/**
* Retrieves the value for the specified reference name (aka context key).
*/
public Object get(Object refName)
{
String key = String.valueOf(refName);
if (safeMode && key.indexOf('.') >= 0)
{
return null;
}
return this.context.getVelocityContext().get(key);
}
}