// 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 org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hivemind.Resource;
import org.apache.hivemind.util.Defense;
import org.apache.tapestry.*;
import org.apache.tapestry.asset.AssetFactory;
import org.apache.tapestry.engine.IEngineService;
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.PageRenderSupportImpl;
import org.apache.tapestry.util.ScriptUtils;
import org.apache.tapestry.web.WebResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.*;
/**
* 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.
*
*/
public class DojoAjaxResponseBuilder implements ResponseBuilder
{
private static final Log _log = LogFactory.getLog(DojoAjaxResponseBuilder.class);
private static final String NEWLINE = System.getProperty("line.separator");
private final AssetFactory _assetFactory;
private final String _namespace;
private PageRenderSupportImpl _prs;
// used to create IMarkupWriter
private RequestLocaleManager _localeManager;
private MarkupWriterSource _markupWriterSource;
private WebResponse _response;
private List _errorPages;
private ContentType _contentType;
// 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();
// List of status messages.
private List _statusMessages;
private IRequestCycle _cycle;
private IEngineService _pageService;
/**
* Keeps track of renders involving a whole page response, such
* as exception pages or pages activated via {@link IRequestCycle#activate(IPage)}.
*/
private boolean _pageRender = false;
/**
* Used to keep track of whether or not the appropriate xml response start
* block has been started.
*/
private boolean _responseStarted = false;
/**
* Creates a builder with a pre-configured {@link IMarkupWriter}.
* Currently only used for testing.
*
* @param cycle
* The current cycle.
* @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.
* @param errorPages
* List of page names known to be exception pages.
*/
public DojoAjaxResponseBuilder(IRequestCycle cycle, IMarkupWriter writer, List parts, List errorPages)
{
Defense.notNull(cycle, "cycle");
Defense.notNull(writer, "writer");
_writer = writer;
_cycle = cycle;
if (parts != null)
_parts.addAll(parts);
_namespace = null;
_assetFactory = null;
_errorPages = errorPages;
}
/**
* Creates a builder with a pre-configured {@link IMarkupWriter}.
* Currently only used for testing.
*
* @param cycle
* Current request.
* @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(IRequestCycle cycle, IMarkupWriter writer, List parts)
{
this(cycle, writer, parts, null);
}
/**
* Creates a new response builder with the required services it needs
* to render the response when {@link #renderResponse(IRequestCycle)} is called.
*
* @param cycle
* The current request.
* @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.
* @param errorPages
* List of page names known to be exception pages.
* @param assetFactory
* Used to manage asset source inclusions.
* @param namespace
* The core namespace to use for javascript/client side operations.
* @param pageService
* {@link org.apache.tapestry.engine.PageService} used to generate page urls.
*/
public DojoAjaxResponseBuilder(IRequestCycle cycle,
RequestLocaleManager localeManager,
MarkupWriterSource markupWriterSource,
WebResponse webResponse, List errorPages,
AssetFactory assetFactory, String namespace, IEngineService pageService)
{
Defense.notNull(cycle, "cycle");
Defense.notNull(assetFactory, "assetService");
_cycle = cycle;
_localeManager = localeManager;
_markupWriterSource = markupWriterSource;
_response = webResponse;
_errorPages = errorPages;
_pageService = pageService;
// Used by PageRenderSupport
_assetFactory = assetFactory;
_namespace = namespace;
}
/**
*
* {@inheritDoc}
*/
public boolean isDynamic()
{
return true;
}
/**
* {@inheritDoc}
*/
public void renderResponse(IRequestCycle cycle)
throws IOException
{
// if response was already started
if (_responseStarted)
{
// clear out any previous input
clearPartialWriters();
cycle.renderPage(this);
TapestryUtils.removePageRenderSupport(cycle);
endResponse();
_writer.close();
return;
}
_localeManager.persistLocale();
_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);
}
if (_writer == null)
{
parseParameters(cycle);
PrintWriter printWriter = _response.getPrintWriter(_contentType);
_writer = _markupWriterSource.newMarkupWriter(printWriter, _contentType);
}
// render response
_prs = new PageRenderSupportImpl(_assetFactory, _namespace, cycle.getPage().getLocation(), this);
TapestryUtils.storePageRenderSupport(cycle, _prs);
cycle.renderPage(this);
TapestryUtils.removePageRenderSupport(cycle);
endResponse();
_writer.close();
}
public void flush()
throws IOException
{
// Important - causes any cookies stored to properly be written out before the
// rest of the response starts being written - see TAPESTRY-825
_writer.flush();
if (!_responseStarted)
beginResponse();
}
/**
* {@inheritDoc}
*/
public void updateComponent(String id)
{
if (!_parts.contains(id))
_parts.add(id);
}
/**
* {@inheritDoc}
*/
public IMarkupWriter getWriter()
{
return _writer;
}
void setWriter(IMarkupWriter writer)
{
_writer = writer;
}
/**
* {@inheritDoc}
*/
public boolean isBodyScriptAllowed(IComponent target)
{
if (_pageRender)
return true;
if (target != null
&& IPage.class.isInstance(target)
|| (IForm.class.isInstance(target)
&& ((IForm)target).isFormFieldUpdating()))
return true;
return contains(target);
}
/**
* {@inheritDoc}
*/
public boolean isExternalScriptAllowed(IComponent target)
{
if (_pageRender)
return true;
if (target != null
&& IPage.class.isInstance(target)
|| (IForm.class.isInstance(target)
&& ((IForm)target).isFormFieldUpdating()))
return true;
return contains(target);
}
/**
* {@inheritDoc}
*/
public boolean isInitializationScriptAllowed(IComponent target)
{
if (_log.isDebugEnabled())
{
_log.debug("isInitializationScriptAllowed(" + target + ") contains?: " + contains(target) + " _pageRender: " + _pageRender);
}
if (_pageRender)
return true;
if (target != null
&& IPage.class.isInstance(target)
|| (IForm.class.isInstance(target)
&& ((IForm)target).isFormFieldUpdating()))
return true;
return contains(target);
}
/**
* {@inheritDoc}
*/
public boolean isImageInitializationAllowed(IComponent target)
{
if (_pageRender)
return true;
if (target != null
&& IPage.class.isInstance(target)
|| (IForm.class.isInstance(target)
&& ((IForm)target).isFormFieldUpdating()))
return true;
return contains(target);
}
/**
* {@inheritDoc}
*/
public String getPreloadedImageReference(IComponent target, IAsset source)
{
return _prs.getPreloadedImageReference(target, source);
}
/**
* {@inheritDoc}
*/
public String getPreloadedImageReference(IComponent target, String url)
{
return _prs.getPreloadedImageReference(target, url);
}
/**
* {@inheritDoc}
*/
public String getPreloadedImageReference(String url)
{
return _prs.getPreloadedImageReference(url);
}
/**
* {@inheritDoc}
*/
public void addBodyScript(IComponent target, String script)
{
_prs.addBodyScript(target, script);
}
/**
* {@inheritDoc}
*/
public void addBodyScript(String script)
{
_prs.addBodyScript(script);
}
/**
* {@inheritDoc}
*/
public void addExternalScript(IComponent target, Resource resource)
{
_prs.addExternalScript(target, resource);
}
/**
* {@inheritDoc}
*/
public void addExternalScript(Resource resource)
{
_prs.addExternalScript(resource);
}
/**
* {@inheritDoc}
*/
public void addInitializationScript(IComponent target, String script)
{
_prs.addInitializationScript(target, script);
}
/**
* {@inheritDoc}
*/
public void addInitializationScript(String script)
{
_prs.addInitializationScript(script);
}
public void addScriptAfterInitialization(IComponent target, String script)
{
_prs.addScriptAfterInitialization(target, script);
}
/**
* {@inheritDoc}
*/
public String getUniqueString(String baseValue)
{
return _prs.getUniqueString(baseValue);
}
/**
* {@inheritDoc}
*/
public void writeBodyScript(IMarkupWriter writer, IRequestCycle cycle)
{
_prs.writeBodyScript(writer, cycle);
}
/**
* {@inheritDoc}
*/
public void writeInitializationScript(IMarkupWriter writer)
{
_prs.writeInitializationScript(writer);
}
/**
* {@inheritDoc}
*/
public void beginBodyScript(IMarkupWriter normalWriter, IRequestCycle cycle)
{
IMarkupWriter writer = getWriter(ResponseBuilder.BODY_SCRIPT, ResponseBuilder.SCRIPT_TYPE);
writer.begin("script");
writer.printRaw(NEWLINE + "//<![CDATA[" + NEWLINE);
}
/**
* {@inheritDoc}
*/
public void endBodyScript(IMarkupWriter normalWriter, IRequestCycle cycle)
{
IMarkupWriter writer = getWriter(ResponseBuilder.BODY_SCRIPT, ResponseBuilder.SCRIPT_TYPE);
writer.printRaw(NEWLINE + "//]]>" + NEWLINE);
writer.end();
}
/**
* {@inheritDoc}
*/
public void writeBodyScript(IMarkupWriter normalWriter, String script, IRequestCycle cycle)
{
IMarkupWriter writer = getWriter(ResponseBuilder.BODY_SCRIPT, ResponseBuilder.SCRIPT_TYPE);
writer.printRaw(script);
}
/**
* {@inheritDoc}
*/
public void writeExternalScript(IMarkupWriter normalWriter, String url, IRequestCycle cycle)
{
IMarkupWriter writer = getWriter(ResponseBuilder.INCLUDE_SCRIPT, ResponseBuilder.SCRIPT_TYPE);
// causes asset includes to be loaded dynamically into document head
writer.beginEmpty("include");
writer.attribute("url", url);
}
/**
* {@inheritDoc}
*/
public void writeImageInitializations(IMarkupWriter normalWriter, String script, String preloadName, IRequestCycle cycle)
{
IMarkupWriter writer = getWriter(ResponseBuilder.BODY_SCRIPT, ResponseBuilder.SCRIPT_TYPE);
writer.printRaw(NEWLINE + preloadName + " = [];" + NEWLINE);
writer.printRaw("if (document.images) {" + NEWLINE);
writer.printRaw(script);
writer.printRaw("}" + NEWLINE);
}
/**
* {@inheritDoc}
*/
public void writeInitializationScript(IMarkupWriter normalWriter, 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(NEWLINE + "//<![CDATA[" + NEWLINE);
writer.printRaw(script);
writer.printRaw(NEWLINE + "//]]>" + NEWLINE);
writer.end();
}
public void addStatus(IMarkupWriter normalWriter, String text)
{
addStatusMessage(normalWriter, "info", text);
}
/**
* Adds a status message to the current response. This implementation keeps track
* of all messages and appends them to the XHR response. On the client side,
* the default behavior is to publish the message to a topic matching the category name
* using <code>dojo.event.topic.publish(category,text);</code>.
*
* @param normalWriter
* The markup writer to use, this may be ignored or swapped
* out for a different writer depending on the implementation being used.
* @param category
* Allows setting a category that best describes the type of the status message,
* i.e. info, error, e.t.c.
* @param text
* The status message.
*/
public void addStatusMessage(IMarkupWriter normalWriter, String category, String text)
{
if (_statusMessages==null)
{
_statusMessages = new ArrayList();
}
_statusMessages.add(category);
_statusMessages.add(text);
}
void writeStatusMessages() {
for (int i=0; i < _statusMessages.size(); i+=2)
{
IMarkupWriter writer = getWriter((String) _statusMessages.get(i), "status");
writer.printRaw((String) _statusMessages.get(i+1));
}
_statusMessages = null;
}
/**
* {@inheritDoc}
*/
public void render(IMarkupWriter writer, IRender render, IRequestCycle cycle)
{
// must be a valid writer already
if (NestedMarkupWriterImpl.class.isInstance(writer) && !NullWriter.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))
{
IPage page = (IPage)render;
String errorPage = getErrorPage(page.getPageName());
if (errorPage != null)
{
_pageRender = true;
clearPartialWriters();
render.render(getWriter(errorPage, EXCEPTION_TYPE), cycle);
return;
}
// If a page other than the active page originally requested is rendered
// it means someone activated a new page, so we need to tell the client to handle
// this appropriately. (usually by replacing the current dom with whatever this renders)
if (_cycle.getParameter(ServiceConstants.PAGE) != null
&& !page.getPageName().equals(_cycle.getParameter(ServiceConstants.PAGE)))
{
IMarkupWriter urlwriter = _writer.getNestedWriter();
urlwriter.begin("response");
urlwriter.attribute("type", PAGE_TYPE);
urlwriter.attribute("url", _pageService.getLink(true, page.getPageName()).getAbsoluteURL());
_writers.put(PAGE_TYPE, urlwriter);
return;
}
}
if (IComponent.class.isInstance(render)
&& contains((IComponent)render, ((IComponent)render).peekClientId()))
{
render.render(getComponentWriter( ((IComponent)render).peekClientId() ), 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;
}
IMarkupWriter getComponentWriter(String id)
{
return getWriter(id, ELEMENT_TYPE);
}
/**
*
* {@inheritDoc}
*/
public IMarkupWriter getWriter(String id, String type)
{
Defense.notNull(id, "id can't be null");
if (!_responseStarted)
beginResponse();
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()
{
_responseStarted = true;
_writer.printRaw("<?xml version=\"1.0\" encoding=\"" + _cycle.getInfrastructure().getOutputEncoding() + "\"?>");
_writer.printRaw("<!DOCTYPE html "
+ "PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" "
+ "\"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\" [" + NEWLINE
+ "<!ENTITY nbsp ' '>" + NEWLINE
+ "]>" + NEWLINE);
_writer.printRaw("<ajax-response>");
}
/**
* Invoked to clear out tempoary partial writer buffers before rendering exception
* page.
*/
void clearPartialWriters()
{
_writers.clear();
}
/**
* 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()
{
if (!_responseStarted)
{
beginResponse();
}
// write out captured content
if (_statusMessages != null)
writeStatusMessages();
Iterator keys = _writers.keySet().iterator();
String buffer;
while (keys.hasNext())
{
String key = (String)keys.next();
NestedMarkupWriter nw = (NestedMarkupWriter)_writers.get(key);
buffer = nw.getBuffer();
if (_log.isDebugEnabled())
{
_log.debug("Ajax markup buffer for key <" + key + " contains: " + buffer);
}
if (!isScriptWriter(key))
_writer.printRaw(ScriptUtils.ensureValidScriptTags(buffer));
else
_writer.printRaw(buffer);
}
// 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.
*/
public boolean contains(IComponent target)
{
if (target == null)
return false;
String id = target.getClientId();
return contains(target, id);
}
boolean contains(IComponent target, String id)
{
if (_parts.contains(id))
return true;
Iterator it = _cycle.renderStackIterator();
while (it.hasNext())
{
IComponent comp = (IComponent)it.next();
String compId = comp.getClientId();
if (comp != target && _parts.contains(compId))
return true;
}
return false;
}
/**
* {@inheritDoc}
*/
public boolean explicitlyContains(IComponent target)
{
if (target == null)
return false;
return _parts.contains(target.getId());
}
}