// Copyright May 8, 2006 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.services.impl;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.apache.hivemind.util.Defense;
import org.apache.tapestry.IComponent;
import org.apache.tapestry.IForm;
import org.apache.tapestry.IMarkupWriter;
import org.apache.tapestry.IPage;
import org.apache.tapestry.IRender;
import org.apache.tapestry.IRequestCycle;
import org.apache.tapestry.NestedMarkupWriter;
import org.apache.tapestry.engine.NullWriter;
import org.apache.tapestry.markup.MarkupWriterSource;
import org.apache.tapestry.markup.NestedMarkupWriterImpl;
import org.apache.tapestry.services.RequestLocaleManager;
import org.apache.tapestry.services.ResponseBuilder;
import org.apache.tapestry.services.ServiceConstants;
import org.apache.tapestry.util.ContentType;
import org.apache.tapestry.util.ScriptUtils;
import org.apache.tapestry.web.WebResponse;
/**
* Main class that handles dojo based ajax responses. These responses are wrapped
* by an xml document format that segments off invididual component/javascript response
* types into easy to manage xml elements that can then be interpreted and managed by
* running client-side javascript.
*
* @author jkuhnert
*/
public class DojoAjaxResponseBuilder implements ResponseBuilder
{
// used to create IMarkupWriter
private RequestLocaleManager _localeManager;
private MarkupWriterSource _markupWriterSource;
private WebResponse _webResponse;
private List _errorPages;
// our response writer
private IMarkupWriter _writer;
// Parts that will be updated.
private List _parts = new ArrayList();
// Map of specialized writers, like scripts
private Map _writers = new HashMap();
/**
* Creates a builder with a pre-configured {@link IMarkupWriter}.
* Currently only used for testing.
*
* @param writer
* The markup writer to render all "good" content to.
* @param parts
* A set of string ids of the components that may have
* their responses rendered.
*/
public DojoAjaxResponseBuilder(IMarkupWriter writer, List parts)
{
_writer = writer;
if (parts != null) _parts.addAll(parts);
}
/**
* Creates a new response builder with the required services it needs
* to render the response when {@link #renderResponse(IRequestCycle)} is called.
*
* @param localeManager
* Used to set the locale on the response.
* @param markupWriterSource
* Creates IJSONWriter instance to be used.
* @param webResponse
* Web response for output stream.
*/
public DojoAjaxResponseBuilder(RequestLocaleManager localeManager,
MarkupWriterSource markupWriterSource,
WebResponse webResponse, List errorPages)
{
_localeManager = localeManager;
_markupWriterSource = markupWriterSource;
_webResponse = webResponse;
_errorPages = errorPages;
}
/**
*
* {@inheritDoc}
*/
public boolean isDynamic()
{
return Boolean.TRUE;
}
/**
* {@inheritDoc}
*/
public void renderResponse(IRequestCycle cycle)
throws IOException
{
_localeManager.persistLocale();
ContentType contentType = new ContentType(CONTENT_TYPE
+ ";charset=" + cycle.getInfrastructure().getOutputEncoding());
String encoding = contentType.getParameter(ENCODING_KEY);
if (encoding == null)
{
encoding = cycle.getEngine().getOutputEncoding();
contentType.setParameter(ENCODING_KEY, encoding);
}
PrintWriter printWriter = _webResponse.getPrintWriter(contentType);
_writer = _markupWriterSource.newMarkupWriter(printWriter, contentType);
parseParameters(cycle);
beginResponse();
// render response
cycle.renderPage(this);
endResponse();
_writer.close();
}
/**
* {@inheritDoc}
*/
public void updateComponent(String id)
{
if (!_parts.contains(id))
_parts.add(id);
}
/**
* {@inheritDoc}
*/
public IMarkupWriter getWriter()
{
return _writer;
}
/**
* {@inheritDoc}
*/
public boolean isBodyScriptAllowed(IComponent target)
{
if (target != null
&& IForm.class.isInstance(target)
&& ((IForm)target).isFormFieldUpdating())
return true;
return contains(target);
}
/**
* {@inheritDoc}
*/
public boolean isExternalScriptAllowed(IComponent target)
{
if (target != null
&& IForm.class.isInstance(target)
&& ((IForm)target).isFormFieldUpdating())
return true;
return contains(target);
}
/**
* {@inheritDoc}
*/
public boolean isInitializationScriptAllowed(IComponent target)
{
if (target != null
&& IForm.class.isInstance(target)
&& ((IForm)target).isFormFieldUpdating())
return true;
return contains(target);
}
/**
* {@inheritDoc}
*/
public void beginBodyScript(IRequestCycle cycle)
{
IMarkupWriter writer = getWriter(ResponseBuilder.BODY_SCRIPT, ResponseBuilder.SCRIPT_TYPE);
writer.begin("script");
writer.printRaw("\n//<![CDATA[\n");
}
/**
* {@inheritDoc}
*/
public void endBodyScript(IRequestCycle cycle)
{
IMarkupWriter writer = getWriter(ResponseBuilder.BODY_SCRIPT, ResponseBuilder.SCRIPT_TYPE);
writer.printRaw("\n//]]>\n");
writer.end();
}
/**
* {@inheritDoc}
*/
public void writeBodyScript(String script, IRequestCycle cycle)
{
IMarkupWriter writer = getWriter(ResponseBuilder.BODY_SCRIPT, ResponseBuilder.SCRIPT_TYPE);
writer.printRaw(script);
}
/**
* {@inheritDoc}
*/
public void writeExternalScript(String url, IRequestCycle cycle)
{
IMarkupWriter writer = getWriter(ResponseBuilder.INCLUDE_SCRIPT, ResponseBuilder.SCRIPT_TYPE);
// causes asset includes to be loaded dynamically into document head
writer.printRaw("tapestry.loadScriptFromUrl(\"");
writer.print(url);
writer.printRaw("\");");
writer.println();
}
/**
* {@inheritDoc}
*/
public void writeImageInitializations(String script, String preloadName, IRequestCycle cycle)
{
IMarkupWriter writer = getWriter(ResponseBuilder.BODY_SCRIPT, ResponseBuilder.SCRIPT_TYPE);
writer.printRaw("\n\nvar " + preloadName + " = new Array();\n");
writer.printRaw("if (document.images)\n");
writer.printRaw("{\n");
writer.printRaw(script);
writer.printRaw("}\n");
}
/**
* {@inheritDoc}
*/
public void writeInitializationScript(String script)
{
IMarkupWriter writer = getWriter(ResponseBuilder.INITIALIZATION_SCRIPT, ResponseBuilder.SCRIPT_TYPE);
writer.begin("script");
// return is in XML so must escape any potentially non-xml compliant content
writer.printRaw("\n//<![CDATA[\n");
writer.printRaw(script);
writer.printRaw("\n//]]>\n");
writer.end();
}
/**
* {@inheritDoc}
*/
public void render(IMarkupWriter writer, IRender render, IRequestCycle cycle)
{
// must be a valid writer already
if (NestedMarkupWriterImpl.class.isInstance(writer)) {
render.render(writer, cycle);
return;
}
// check for page exception renders and write content to writer so client can display them
if (IPage.class.isInstance(render)) {
String errorPage = getErrorPage(((IPage)render).getPageName());
if (errorPage != null) {
render.render(getWriter(errorPage, EXCEPTION_TYPE), cycle);
return;
}
}
if (IComponent.class.isInstance(render)
&& contains((IComponent)render))
{
render.render(getComponentWriter((IComponent)render), cycle);
return;
}
// Nothing else found, throw out response
render.render(NullWriter.getSharedInstance(), cycle);
}
private String getErrorPage(String pageName)
{
for (int i=0; i < _errorPages.size(); i++) {
String page = (String)_errorPages.get(i);
if (pageName.indexOf(page) > -1)
return page;
}
return null;
}
/**
* Gets a {@link NestedMarkupWriter} for the specified
* component to write to and caches the buffer for later
* writing.
*
* @param target
* The component to get a writer for.
* @return An IMarkuPWriter instance.
*/
IMarkupWriter getComponentWriter(IComponent target)
{
String id = getComponentId(target);
return getWriter(id, ELEMENT_TYPE);
}
/**
*
* {@inheritDoc}
*/
public IMarkupWriter getWriter(String id, String type)
{
Defense.notNull(id, "id can't be null");
IMarkupWriter w = (IMarkupWriter)_writers.get(id);
if (w != null)
return w;
// Make component write to a "nested" writer
// so that element begin/ends don't conflict
// with xml element response begin/ends. This is very
// important.
IMarkupWriter nestedWriter = _writer.getNestedWriter();
nestedWriter.begin("response");
nestedWriter.attribute("id", id);
if (type != null)
nestedWriter.attribute("type", type);
_writers.put(id, nestedWriter);
return nestedWriter;
}
/**
* Called to start an ajax response. Writes xml doctype and starts
* the <code>ajax-response</code> element that will contain all of
* the returned content.
*/
void beginResponse()
{
_writer.printRaw("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
_writer.printRaw("<!DOCTYPE html "
+ "PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" "
+ "\"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\" [\n"
+ "<!ENTITY nbsp ' '>\n"
+ "]>\n");
_writer.printRaw("<ajax-response>");
}
/**
* Called after the entire response has been captured. Causes
* the writer buffer output captured to be segmented and written
* out to the right response elements for the client libraries to parse.
*/
void endResponse()
{
// write out captured content
Iterator keys = _writers.keySet().iterator();
while (keys.hasNext()) {
String key = (String)keys.next();
NestedMarkupWriter nw = (NestedMarkupWriter)_writers.get(key);
nw.end();
if (!isScriptWriter(key))
_writer.printRaw(ScriptUtils.ensureValidScriptTags(nw.getBuffer()));
else
_writer.printRaw(nw.getBuffer());
}
//end response
_writer.printRaw("</ajax-response>");
_writer.flush();
}
/**
* Determines if the specified markup writer key is one of
* the pre-defined script keys from ResponseBuilder.
*
* @param key
* The key to check.
* @return True, if key is one of the ResponseBuilder keys.
* (BODY_SCRIPT,INCLUDE_SCRIPT,INITIALIZATION_SCRIPT)
*/
boolean isScriptWriter(String key)
{
if (key == null)
return false;
if (ResponseBuilder.BODY_SCRIPT.equals(key)
|| ResponseBuilder.INCLUDE_SCRIPT.equals(key)
|| ResponseBuilder.INITIALIZATION_SCRIPT.equals(key))
return true;
return false;
}
/**
* Grabs the incoming parameters needed for json responses, most notable the
* {@link ServiceConstants#UPDATE_PARTS} parameter.
*
* @param cycle
* The request cycle to parse from
*/
void parseParameters(IRequestCycle cycle)
{
Object[] updateParts = cycle.getParameters(ServiceConstants.UPDATE_PARTS);
if (updateParts == null)
return;
for(int i = 0; i < updateParts.length; i++)
_parts.add(updateParts[i].toString());
}
/**
* Determines if the specified component is contained in the
* responses requested update parts.
* @param target
* The component to check for.
* @return True if the request should capture the components output.
*/
boolean contains(IComponent target)
{
if (target == null)
return false;
return _parts.contains(getComponentId(target));
}
/**
* Gets the id of the specified component, choosing the "id" element
* binding over any other id.
* @param comp
* @return The id of the component.
*/
String getComponentId(IComponent comp)
{
return comp.getClientId();
}
}