/*
* 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.
*/
package org.apache.wicket.page;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import javax.servlet.http.Cookie;
import org.apache.wicket.Component;
import org.apache.wicket.Page;
import org.apache.wicket.markup.head.HeaderItem;
import org.apache.wicket.markup.head.IHeaderResponse;
import org.apache.wicket.markup.head.IWrappedHeaderItem;
import org.apache.wicket.markup.head.OnDomReadyHeaderItem;
import org.apache.wicket.markup.head.OnEventHeaderItem;
import org.apache.wicket.markup.head.OnLoadHeaderItem;
import org.apache.wicket.markup.head.PriorityHeaderItem;
import org.apache.wicket.markup.head.internal.HeaderResponse;
import org.apache.wicket.markup.html.internal.HtmlHeaderContainer;
import org.apache.wicket.markup.parser.filter.HtmlHeaderSectionHandler;
import org.apache.wicket.markup.renderStrategy.AbstractHeaderRenderStrategy;
import org.apache.wicket.markup.renderStrategy.IHeaderRenderStrategy;
import org.apache.wicket.markup.repeater.AbstractRepeater;
import org.apache.wicket.request.IRequestCycle;
import org.apache.wicket.request.Response;
import org.apache.wicket.request.cycle.RequestCycle;
import org.apache.wicket.request.http.WebResponse;
import org.apache.wicket.util.lang.Args;
import org.apache.wicket.util.lang.Classes;
import org.apache.wicket.util.lang.Generics;
import org.apache.wicket.util.string.AppendingStringBuffer;
import org.apache.wicket.util.time.Time;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A partial update of a page that collects components and header contributions to be written to the client in a specific
* String-based format (XML, JSON, * ...).
* <p>
* The elements of such response are:
* <ul>
* <li>priority-evaluate - an item of the prepend JavaScripts</li>
* <li>component - the markup of the updated component</li>
* <li>evaluate - an item of the onDomReady and append JavaScripts</li>
* <li>header-contribution - all HeaderItems which have been contributed in
* components' and their behaviors' #renderHead(Component, IHeaderResponse)</li>
* </ul>
*/
public abstract class PartialPageUpdate
{
private static final Logger LOG = LoggerFactory.getLogger(PartialPageUpdate.class);
/**
* A list of scripts (JavaScript) which should be executed on the client side before the
* components' replacement
*/
protected final List<CharSequence> prependJavaScripts = Generics.newArrayList();
/**
* A list of scripts (JavaScript) which should be executed on the client side after the
* components' replacement
*/
protected final List<CharSequence> appendJavaScripts = Generics.newArrayList();
/**
* A list of scripts (JavaScript) which should be executed on the client side after the
* components' replacement.
* Executed immediately after the replacement of the components, and before appendJavaScripts
*/
protected final List<CharSequence> domReadyJavaScripts = Generics.newArrayList();
/**
* The component instances that will be rendered/replaced.
*/
protected final Map<String, Component> markupIdToComponent = new LinkedHashMap<String, Component>();
/**
* A flag that indicates that components cannot be added anymore.
* See https://issues.apache.org/jira/browse/WICKET-3564
*
* @see #add(Component, String)
*/
protected transient boolean componentsFrozen;
/**
* Buffer of response body.
*/
protected final ResponseBuffer bodyBuffer;
/**
* Buffer of response header.
*/
protected final ResponseBuffer headerBuffer;
protected HtmlHeaderContainer header = null;
private Component originalHeaderContainer = null;
// whether a header contribution is being rendered
private boolean headerRendering = false;
private IHeaderResponse headerResponse;
/**
* The page which components are being updated.
*/
private final Page page;
/**
* Constructor.
*
* @param page
* the page which components are being updated.
*/
public PartialPageUpdate(final Page page)
{
this.page = page;
this.originalHeaderContainer = page.get(HtmlHeaderSectionHandler.HEADER_ID);
WebResponse response = (WebResponse) page.getResponse();
bodyBuffer = new ResponseBuffer(response);
headerBuffer = new ResponseBuffer(response);
}
/**
* Serializes this object to the response.
*
* @param response
* the response to write to
* @param encoding
* the encoding for the response
*/
public void writeTo(final Response response, final String encoding)
{
try {
writeHeader(response, encoding);
onBeforeRespond(response);
// process added components
writeComponents(response, encoding);
onAfterRespond(response);
// queue up prepend javascripts. unlike other steps these are executed out of order so that
// components can contribute them from inside their onbeforerender methods.
writePriorityEvaluations(response, prependJavaScripts);
// execute the dom ready javascripts as first javascripts
// after component replacement
List<CharSequence> evaluationScripts = new ArrayList<>();
evaluationScripts.addAll(domReadyJavaScripts);
evaluationScripts.addAll(appendJavaScripts);
writeNormalEvaluations(response, evaluationScripts);
writeFooter(response, encoding);
} finally {
if (header != null && originalHeaderContainer!= null) {
// restore a normal header
page.replace(originalHeaderContainer);
header = null;
}
}
}
/**
* Hook-method called before components are written.
*
* @param response
*/
protected void onBeforeRespond(Response response) {
}
/**
* Hook-method called after components are written.
*
* @param response
*/
protected void onAfterRespond(Response response) {
}
/**
* @param response
* the response to write to
* @param encoding
* the encoding for the response
*/
protected abstract void writeFooter(Response response, String encoding);
/**
*
* @param response
* the response to write to
* @param js
* the JavaScript to evaluate
*/
protected abstract void writePriorityEvaluations(Response response, Collection<CharSequence> js);
/**
*
* @param response
* the response to write to
* @param js
* the JavaScript to evaluate
*/
protected abstract void writeNormalEvaluations(Response response, Collection<CharSequence> js);
/**
* Processes components added to the target. This involves attaching components, rendering
* markup into a client side xml envelope, and detaching them
*
* @param response
* the response to write to
* @param encoding
* the encoding for the response
*/
private void writeComponents(Response response, String encoding)
{
componentsFrozen = true;
// process component markup
for (Map.Entry<String, Component> stringComponentEntry : markupIdToComponent.entrySet())
{
final Component component = stringComponentEntry.getValue();
if (!containsAncestorFor(component))
{
writeComponent(response, component.getAjaxRegionMarkupId(), component, encoding);
}
}
if (header != null)
{
// some header responses buffer all calls to render*** until close is called.
// when they are closed, they do something (i.e. aggregate all JS resource urls to a
// single url), and then "flush" (by writing to the real response) before closing.
// to support this, we need to allow header contributions to be written in the close
// tag, which we do here:
headerRendering = true;
// save old response, set new
Response oldResponse = RequestCycle.get().setResponse(headerBuffer);
headerBuffer.reset();
// now, close the response (which may render things)
header.getHeaderResponse().close();
// revert to old response
RequestCycle.get().setResponse(oldResponse);
// write the XML tags and we're done
writeHeaderContribution(response);
headerRendering = false;
}
}
/**
* Writes a single component
*
* @param response
* the response to write to
* @param markupId
* the markup id to use for the component replacement
* @param component
* the component which markup will be used as replacement
* @param encoding
* the encoding for the response
*/
protected abstract void writeComponent(Response response, String markupId, Component component, String encoding);
/**
* Writes the head part of the response.
* For example XML preamble
*
* @param response
* the response to write to
* @param encoding
* the encoding for the response
*/
protected abstract void writeHeader(Response response, String encoding);
/**
* Writes header contribution (<link/> or <script/>) to the response.
*
* @param response
* the response to write to
*/
protected abstract void writeHeaderContribution(Response response);
@Override
public boolean equals(Object o)
{
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
PartialPageUpdate that = (PartialPageUpdate) o;
if (!appendJavaScripts.equals(that.appendJavaScripts)) return false;
if (!domReadyJavaScripts.equals(that.domReadyJavaScripts)) return false;
return prependJavaScripts.equals(that.prependJavaScripts);
}
@Override
public int hashCode()
{
int result = prependJavaScripts.hashCode();
result = 31 * result + appendJavaScripts.hashCode();
result = 31 * result + domReadyJavaScripts.hashCode();
return result;
}
/**
* Adds script to the ones which are executed after the component replacement.
*
* @param javascript
* the javascript to execute
*/
public final void appendJavaScript(final CharSequence javascript)
{
Args.notNull(javascript, "javascript");
appendJavaScripts.add(javascript);
}
/**
* Adds script to the ones which are executed before the component replacement.
*
* @param javascript
* the javascript to execute
*/
public final void prependJavaScript(CharSequence javascript)
{
Args.notNull(javascript, "javascript");
prependJavaScripts.add(javascript);
}
/**
* Adds a component to be updated at the client side with its current markup
*
* @param component
* the component to update
* @param markupId
* the markup id to use to find the component in the page's markup
* @throws IllegalArgumentException
* thrown when a Page or an AbstractRepeater is added
* @throws IllegalStateException
* thrown when components no more can be added for replacement.
*/
public final void add(final Component component, final String markupId)
throws IllegalArgumentException, IllegalStateException
{
Args.notEmpty(markupId, "markupId");
Args.notNull(component, "component");
if (component instanceof Page)
{
if (component != page)
{
throw new IllegalArgumentException("component cannot be a page");
}
}
else if (component instanceof AbstractRepeater)
{
throw new IllegalArgumentException(
"Component " +
component.getClass().getName() +
" has been added to a partial page update. This component is a repeater and cannot be repainted directly. " +
"Instead add its parent or another markup container higher in the hierarchy.");
}
assertComponentsNotFrozen();
component.setMarkupId(markupId);
markupIdToComponent.put(markupId, component);
}
/**
* @return a read-only collection of all components which have been added for replacement so far.
*/
public final Collection<? extends Component> getComponents()
{
return Collections.unmodifiableCollection(markupIdToComponent.values());
}
/**
* Detaches the page if at least one of its components was updated.
*
* @param requestCycle
* the current request cycle
*/
public void detach(IRequestCycle requestCycle)
{
Iterator<Component> iterator = markupIdToComponent.values().iterator();
while (iterator.hasNext())
{
final Component component = iterator.next();
final Page parentPage = component.findParent(Page.class);
if (parentPage != null)
{
parentPage.detach();
break;
}
}
}
/**
* Checks if the target contains an ancestor for the given component
*
* @param component
* the component which ancestors should be checked.
* @return <code>true</code> if target contains an ancestor for the given component
*/
protected boolean containsAncestorFor(Component component)
{
Component cursor = component.getParent();
while (cursor != null)
{
if (markupIdToComponent.containsValue(cursor))
{
return true;
}
cursor = cursor.getParent();
}
return false;
}
/**
* @return {@code true} if the page has been added for replacement
*/
public boolean containsPage()
{
return markupIdToComponent.values().contains(page);
}
/**
* Gets or creates an IHeaderResponse instance to use for the header contributions.
*
* @return IHeaderResponse instance to use for the header contributions.
*/
public IHeaderResponse getHeaderResponse()
{
if (headerResponse == null)
{
// we don't need to decorate the header response here because this is called from
// within PartialHtmlHeaderContainer, which decorates the response
headerResponse = new PartialHeaderResponse();
}
return headerResponse;
}
/**
* @param response
* the response to write to
* @param component
* to component which will contribute to the header
*/
protected void writeHeaderContribution(final Response response, final Component component)
{
headerRendering = true;
// create the htmlheadercontainer if needed
if (header == null)
{
header = new PartialHtmlHeaderContainer(this);
page.addOrReplace(header);
}
RequestCycle requestCycle = component.getRequestCycle();
// save old response, set new
Response oldResponse = requestCycle.setResponse(headerBuffer);
try {
headerBuffer.reset();
IHeaderRenderStrategy strategy = AbstractHeaderRenderStrategy.get();
strategy.renderHeader(header, null, component);
} finally {
// revert to old response
requestCycle.setResponse(oldResponse);
}
writeHeaderContribution(response);
headerRendering = false;
}
/**
* Sets the Content-Type header to indicate the type of the response.
*
* @param response
* the current we response
* @param encoding
* the encoding to use
*/
public abstract void setContentType(WebResponse response, String encoding);
/**
* Header container component for partial page updates.
* <p>
* This container is temporarily injected into the page to provide the
* {@link IHeaderResponse} while components are rendered. It is never
* rendered itself.
*
* @author Matej Knopp
*/
private static class PartialHtmlHeaderContainer extends HtmlHeaderContainer
{
private static final long serialVersionUID = 1L;
/**
* Keep transiently, in case the containing page gets serialized before
* this container is removed again. This happens when DebugBar determines
* the page size by serializing/deserializing it.
*/
private transient PartialPageUpdate pageUpdate;
/**
* Constructor.
*
* @param update
* the partial page update
*/
public PartialHtmlHeaderContainer(PartialPageUpdate pageUpdate)
{
super(HtmlHeaderSectionHandler.HEADER_ID);
this.pageUpdate = pageUpdate;
}
/**
*
* @see org.apache.wicket.markup.html.internal.HtmlHeaderContainer#newHeaderResponse()
*/
@Override
protected IHeaderResponse newHeaderResponse()
{
if (pageUpdate == null) {
throw new IllegalStateException("disconnected from pageUpdate after serialization");
}
return pageUpdate.getHeaderResponse();
}
}
/**
* Header response for partial updates.
*
* @author Matej Knopp
*/
private class PartialHeaderResponse extends HeaderResponse
{
@Override
public void render(HeaderItem item)
{
PriorityHeaderItem priorityHeaderItem = null;
while (item instanceof IWrappedHeaderItem)
{
if (item instanceof PriorityHeaderItem)
{
priorityHeaderItem = (PriorityHeaderItem) item;
}
item = ((IWrappedHeaderItem) item).getWrapped();
}
if (item instanceof OnLoadHeaderItem)
{
if (!wasItemRendered(item))
{
PartialPageUpdate.this.appendJavaScript(((OnLoadHeaderItem) item).getJavaScript());
markItemRendered(item);
}
}
else if (item instanceof OnEventHeaderItem)
{
if (!wasItemRendered(item))
{
PartialPageUpdate.this.appendJavaScript(((OnEventHeaderItem) item).getCompleteJavaScript());
markItemRendered(item);
}
}
else if (item instanceof OnDomReadyHeaderItem)
{
if (!wasItemRendered(item))
{
if (priorityHeaderItem != null)
{
PartialPageUpdate.this.domReadyJavaScripts.add(0, ((OnDomReadyHeaderItem)item).getJavaScript());
}
else
{
PartialPageUpdate.this.domReadyJavaScripts.add(((OnDomReadyHeaderItem)item).getJavaScript());
}
markItemRendered(item);
}
}
else if (headerRendering)
{
super.render(item);
}
else
{
LOG.debug("Only methods that can be called on IHeaderResponse outside renderHead() are #render(OnLoadHeaderItem) and #render(OnDomReadyHeaderItem)");
}
}
@Override
protected Response getRealResponse()
{
return RequestCycle.get().getResponse();
}
}
/**
* Wrapper of a response that buffers its contents.
*
* @author Igor Vaynberg (ivaynberg)
* @author Sven Meier (svenmeier)
*
* @see ResponseBuffer#getContents()
* @see ResponseBuffer#reset()
*/
protected static final class ResponseBuffer extends WebResponse
{
private final AppendingStringBuffer buffer = new AppendingStringBuffer(256);
private final WebResponse originalResponse;
/**
* Constructor.
*
* @param originalResponse
* the original request cycle response
*/
private ResponseBuffer(WebResponse originalResponse)
{
this.originalResponse = originalResponse;
}
/**
* @see org.apache.wicket.request.Response#encodeURL(CharSequence)
*/
@Override
public String encodeURL(CharSequence url)
{
return originalResponse.encodeURL(url);
}
/**
* @return contents of the response
*/
public CharSequence getContents()
{
return buffer;
}
/**
* @see org.apache.wicket.request.Response#write(CharSequence)
*/
@Override
public void write(CharSequence cs)
{
buffer.append(cs);
}
/**
* Resets the response to a clean state so it can be reused to save on garbage.
*/
@Override
public void reset()
{
buffer.clear();
}
@Override
public void write(byte[] array)
{
throw new UnsupportedOperationException("Cannot write binary data.");
}
@Override
public void write(byte[] array, int offset, int length)
{
throw new UnsupportedOperationException("Cannot write binary data.");
}
@Override
public Object getContainerResponse()
{
return originalResponse.getContainerResponse();
}
@Override
public void addCookie(Cookie cookie)
{
originalResponse.addCookie(cookie);
}
@Override
public void clearCookie(Cookie cookie)
{
originalResponse.clearCookie(cookie);
}
@Override
public void setHeader(String name, String value)
{
originalResponse.setHeader(name, value);
}
@Override
public void addHeader(String name, String value)
{
originalResponse.addHeader(name, value);
}
@Override
public void setDateHeader(String name, Time date)
{
originalResponse.setDateHeader(name, date);
}
@Override
public void setContentLength(long length)
{
originalResponse.setContentLength(length);
}
@Override
public void setContentType(String mimeType)
{
originalResponse.setContentType(mimeType);
}
@Override
public void setStatus(int sc)
{
originalResponse.setStatus(sc);
}
@Override
public void sendError(int sc, String msg)
{
originalResponse.sendError(sc, msg);
}
@Override
public String encodeRedirectURL(CharSequence url)
{
return originalResponse.encodeRedirectURL(url);
}
@Override
public void sendRedirect(String url)
{
originalResponse.sendRedirect(url);
}
@Override
public boolean isRedirect()
{
return originalResponse.isRedirect();
}
@Override
public void flush()
{
originalResponse.flush();
}
}
private void assertComponentsNotFrozen()
{
assertNotFrozen(componentsFrozen, Component.class);
}
private void assertNotFrozen(boolean frozen, Class<?> clazz)
{
if (frozen)
{
throw new IllegalStateException(Classes.simpleName(clazz) + "s can no " +
" longer be added");
}
}
}