/*
* 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.ajax;
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.string.Strings;
import org.apache.wicket.util.time.Time;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A POJO-like that collects the data for the Ajax response written to the client
* and serializes it to specific String-based format (XML, JSON, ...).
*/
public abstract class AbstractAjaxResponse
{
private static final Logger LOG = LoggerFactory.getLogger(AbstractAjaxResponse.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 to AjaxRequestTarget anymore.
* See https://issues.apache.org/jira/browse/WICKET-3564
*/
protected transient boolean componentsFrozen;
/**
* Create a response for component body and javascript that will escape output to make it safe
* to use inside a CDATA block
*/
protected final AjaxResponse encodingBodyResponse;
/**
* Response for header contribution that will escape output to make it safe to use inside a
* CDATA block
*/
protected final AjaxResponse encodingHeaderResponse;
protected HtmlHeaderContainer header = 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 AbstractAjaxResponse(final Page page)
{
this.page = page;
WebResponse response = (WebResponse) page.getResponse();
encodingBodyResponse = new AjaxResponse(response);
encodingHeaderResponse = new AjaxResponse(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)
{
writeHeader(response, encoding);
// invoke onbeforerespond event on listeners
fireOnBeforeRespondListeners();
// process added components
writeComponents(response, encoding);
fireOnAfterRespondListeners(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);
}
protected abstract void fireOnAfterRespondListeners(Response response);
protected abstract void fireOnBeforeRespondListeners();
/**
* @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(encodingHeaderResponse);
encodingHeaderResponse.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;
AbstractAjaxResponse that = (AbstractAjaxResponse) 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 the target. This component is a repeater and cannot be repainted via ajax 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
*/
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 AjaxHtmlHeaderContainer, which decorates the response
headerResponse = new AjaxHeaderResponse();
}
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 AjaxHtmlHeaderContainer(this);
final Page parentPage = component.getPage();
parentPage.addOrReplace(header);
}
RequestCycle requestCycle = component.getRequestCycle();
// save old response, set new
Response oldResponse = requestCycle.setResponse(encodingHeaderResponse);
try {
encodingHeaderResponse.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 Ajax response.
*
* @param response
* the current we response
* @param encoding
* the encoding to use
*/
protected abstract void setContentType(WebResponse response, String encoding);
/**
* Header container component for ajax header contributions
*
* @author Matej Knopp
*/
private static class AjaxHtmlHeaderContainer extends HtmlHeaderContainer
{
private static final long serialVersionUID = 1L;
private final transient AbstractAjaxResponse ajaxResponse;
/**
* Constructor.
*
* @param ajaxResponse
* the object that keeps the data for the Ajax response
*/
public AjaxHtmlHeaderContainer(final AbstractAjaxResponse ajaxResponse)
{
super(HtmlHeaderSectionHandler.HEADER_ID);
this.ajaxResponse = ajaxResponse;
}
/**
*
* @see org.apache.wicket.markup.html.internal.HtmlHeaderContainer#newHeaderResponse()
*/
@Override
protected IHeaderResponse newHeaderResponse()
{
return ajaxResponse.getHeaderResponse();
}
}
/**
* Header response for an ajax request.
*
* @author Matej Knopp
*/
private class AjaxHeaderResponse 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))
{
AbstractAjaxResponse.this.appendJavaScript(((OnLoadHeaderItem) item).getJavaScript());
markItemRendered(item);
}
}
else if (item instanceof OnEventHeaderItem)
{
if (!wasItemRendered(item))
{
AbstractAjaxResponse.this.appendJavaScript(((OnEventHeaderItem) item).getCompleteJavaScript());
markItemRendered(item);
}
}
else if (item instanceof OnDomReadyHeaderItem)
{
if (!wasItemRendered(item))
{
if (priorityHeaderItem != null)
{
AbstractAjaxResponse.this.domReadyJavaScripts.add(0, ((OnDomReadyHeaderItem)item).getJavaScript());
}
else
{
AbstractAjaxResponse.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();
}
}
/**
* Response that uses an encoder to encode its contents
*
* @author Igor Vaynberg (ivaynberg)
*/
protected static final class AjaxResponse extends WebResponse
{
private final AppendingStringBuffer buffer = new AppendingStringBuffer(256);
private boolean escaped = false;
private final WebResponse originalResponse;
/**
* Constructor.
*
* @param originalResponse
* the original request cycle response
*/
private AjaxResponse(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;
}
/**
* @return true if any escaping has been performed, false otherwise
*/
public boolean isContentsEncoded()
{
return escaped;
}
/**
* @see org.apache.wicket.request.Response#write(CharSequence)
*/
@Override
public void write(CharSequence cs)
{
String string = cs.toString();
if (needsEncoding(string))
{
string = encode(string);
escaped = true;
buffer.append(string);
}
else
{
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();
escaped = false;
}
@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();
}
}
/**
* Encodes a string so it is safe to use inside CDATA blocks
*
* @param str
* the string to encode.
* @return encoded string
*/
static String encode(CharSequence str)
{
if (str == null)
{
return null;
}
return Strings.replaceAll(str, "]", "]^").toString();
}
/**
* @return name of encoding used to possibly encode the contents of the CDATA blocks
*/
protected String getEncodingName()
{
return "wicket1";
}
/**
*
* @param str
* the string to check
* @return {@code true} if string needs to be encoded, {@code false} otherwise
*/
static boolean needsEncoding(CharSequence str)
{
/*
* TODO Post 1.2: Ajax: we can improve this by keeping a buffer of at least 3 characters and
* checking that buffer so that we can narrow down escaping occurring only for ']]>'
* sequence, or at least for ]] if ] is the last char in this buffer.
*
* but this improvement will only work if we write first and encode later instead of working
* on fragments sent to write
*/
return Strings.indexOf(str, ']') >= 0;
}
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");
}
}
}