/*
* 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.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.apache.wicket.Application;
import org.apache.wicket.Component;
import org.apache.wicket.MarkupContainer;
import org.apache.wicket.Page;
import org.apache.wicket.core.request.handler.PageProvider;
import org.apache.wicket.core.request.handler.RenderPageRequestHandler;
import org.apache.wicket.core.request.handler.logger.PageLogData;
import org.apache.wicket.event.Broadcast;
import org.apache.wicket.markup.head.IHeaderResponse;
import org.apache.wicket.request.IRequestCycle;
import org.apache.wicket.request.IRequestHandler;
import org.apache.wicket.request.Response;
import org.apache.wicket.request.component.IRequestablePage;
import org.apache.wicket.request.cycle.RequestCycle;
import org.apache.wicket.request.http.WebRequest;
import org.apache.wicket.request.http.WebResponse;
import org.apache.wicket.request.mapper.parameter.PageParameters;
import org.apache.wicket.response.StringResponse;
import org.apache.wicket.response.filter.IResponseFilter;
import org.apache.wicket.util.lang.Args;
import org.apache.wicket.util.string.AppendingStringBuffer;
import org.apache.wicket.util.string.Strings;
import org.apache.wicket.util.visit.IVisit;
import org.apache.wicket.util.visit.IVisitor;
/**
* A request target that produces ajax response envelopes used on the client side to update
* component markup as well as evaluate arbitrary javascript.
* <p>
* A component whose markup needs to be updated should be added to this target via
* AjaxRequestTarget#add(Component) method. Its body will be rendered and added to the envelope when
* the target is processed, and refreshed on the client side when the ajax response is received.
* <p>
* It is important that the component whose markup needs to be updated contains an id attribute in
* the generated markup that is equal to the value retrieved from Component#getMarkupId(). This can
* be accomplished by either setting the id attribute in the html template, or using an attribute
* modifier that will add the attribute with value Component#getMarkupId() to the tag ( such as
* MarkupIdSetter )
* <p>
* Any javascript that needs to be evaluated on the client side can be added using
* AjaxRequestTarget#append/prependJavaScript(String). For example, this feature can be useful when
* it is desirable to link component update with some javascript effects.
* <p>
* The target provides a listener interface {@link AjaxRequestTarget.IListener} that can be used to
* add code that responds to various target events by adding listeners via
* {@link #addListener(AjaxRequestTarget.IListener)}
*
* @since 1.2
*
* @author Igor Vaynberg (ivaynberg)
* @author Eelco Hillenius
*/
public class AjaxRequestHandler implements AjaxRequestTarget
{
/**
* 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, ...).
*/
private final AbstractAjaxResponse responseObject;
/** a list of listeners */
private List<AjaxRequestTarget.IListener> listeners = null;
/** */
private final Set<ITargetRespondListener> respondListeners = new HashSet<ITargetRespondListener>();
/** see https://issues.apache.org/jira/browse/WICKET-3564 */
protected transient boolean respondersFrozen;
protected transient boolean listenersFrozen;
/** The associated Page */
private final Page page;
private PageLogData logData;
/**
* Constructor
*
* @param page
* the currently active page
*/
public AjaxRequestHandler(final Page page)
{
this.page = Args.notNull(page, "page");
responseObject = new XmlAjaxResponse(page)
{
/**
* Freezes the {@link AjaxRequestHandler#listeners}, and does not un-freeze them as the
* events will have been fired by now.
*
* @param response
* the response to write to
*/
@Override
protected void fireOnAfterRespondListeners(final Response response)
{
listenersFrozen = true;
// invoke onafterresponse event on listeners
if (listeners != null)
{
final Map<String, Component> components = Collections.unmodifiableMap(markupIdToComponent);
// create response that will be used by listeners to append
// javascript
final AjaxRequestTarget.IJavaScriptResponse jsresponse = new AjaxRequestTarget.IJavaScriptResponse()
{
@Override
public void addJavaScript(String script)
{
writeNormalEvaluations(response, Collections.<CharSequence>singleton(script));
}
};
for (AjaxRequestTarget.IListener listener : listeners)
{
listener.onAfterRespond(components, jsresponse);
}
}
}
/**
* Freezes the {@link AjaxRequestHandler#listeners} before firing the event and
* un-freezes them afterwards to allow components to add more
* {@link AjaxRequestTarget.IListener}s for the second event.
*/
@Override
protected void fireOnBeforeRespondListeners()
{
listenersFrozen = true;
if (listeners != null)
{
final Map<String, Component> components = Collections.unmodifiableMap(markupIdToComponent);
for (AjaxRequestTarget.IListener listener : listeners)
{
listener.onBeforeRespond(components, AjaxRequestHandler.this);
}
}
listenersFrozen = false;
}
};
}
/**
* @see org.apache.wicket.core.request.handler.IPageRequestHandler#getPage()
*/
@Override
public Page getPage()
{
return page;
}
@Override
public void addListener(AjaxRequestTarget.IListener listener) throws IllegalStateException
{
Args.notNull(listener, "listener");
assertListenersNotFrozen();
if (listeners == null)
{
listeners = new LinkedList<AjaxRequestTarget.IListener>();
}
if (!listeners.contains(listener))
{
listeners.add(listener);
}
}
@Override
public final void addChildren(MarkupContainer parent, Class<?> childCriteria)
{
Args.notNull(parent, "parent");
Args.notNull(childCriteria, "childCriteria");
parent.visitChildren(childCriteria, new IVisitor<Component, Void>()
{
@Override
public void component(final Component component, final IVisit<Void> visit)
{
add(component);
visit.dontGoDeeper();
}
});
}
@Override
public void add(Component... components)
{
for (final Component component : components)
{
Args.notNull(component, "component");
if (component.getOutputMarkupId() == false && !(component instanceof Page))
{
throw new IllegalArgumentException(
"cannot update component that does not have setOutputMarkupId property set to true. Component: " +
component.toString());
}
add(component, component.getMarkupId());
}
}
@Override
public void add(Component component, String markupId)
{
responseObject.add(component, markupId);
}
@Override
public final Collection<? extends Component> getComponents()
{
return responseObject.getComponents();
}
@Override
public final void focusComponent(Component component)
{
if (component != null && component.getOutputMarkupId() == false)
{
throw new IllegalArgumentException(
"cannot update component that does not have setOutputMarkupId property set to true. Component: " +
component.toString());
}
final String id = component != null ? ("'" + component.getMarkupId() + "'") : "null";
appendJavaScript("Wicket.Focus.setFocusOnId(" + id + ");");
}
@Override
public final void appendJavaScript(CharSequence javascript)
{
responseObject.appendJavaScript(javascript);
}
/**
* @see org.apache.wicket.core.request.handler.IPageRequestHandler#detach(org.apache.wicket.request.IRequestCycle)
*/
@Override
public void detach(final IRequestCycle requestCycle)
{
if (logData == null)
{
logData = new PageLogData(page);
}
responseObject.detach(requestCycle);
}
/**
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
public boolean equals(final Object obj)
{
if (obj instanceof AjaxRequestHandler)
{
AjaxRequestHandler that = (AjaxRequestHandler)obj;
return responseObject.equals(that.responseObject);
}
return false;
}
/**
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode()
{
int result = "AjaxRequestHandler".hashCode();
result += responseObject.hashCode() * 17;
return result;
}
@Override
public final void prependJavaScript(CharSequence javascript)
{
responseObject.prependJavaScript(javascript);
}
@Override
public void registerRespondListener(ITargetRespondListener listener)
{
assertRespondersNotFrozen();
respondListeners.add(listener);
}
/**
* @see org.apache.wicket.core.request.handler.IPageRequestHandler#respond(org.apache.wicket.request.IRequestCycle)
*/
@Override
public final void respond(final IRequestCycle requestCycle)
{
final RequestCycle rc = (RequestCycle)requestCycle;
final WebResponse response = (WebResponse)requestCycle.getResponse();
if (responseObject.containsPage())
{
// the page itself has been added to the request target, we simply issue a redirect
// back to the page
IRequestHandler handler = new RenderPageRequestHandler(new PageProvider(page));
final String url = rc.urlFor(handler).toString();
response.sendRedirect(url);
return;
}
respondersFrozen = true;
for (ITargetRespondListener listener : respondListeners)
{
listener.onTargetRespond(this);
}
final Application app = page.getApplication();
page.send(app, Broadcast.BREADTH, this);
// Determine encoding
final String encoding = app.getRequestCycleSettings().getResponseRequestEncoding();
// Set content type based on markup type for page
responseObject.setContentType(response, encoding);
// Make sure it is not cached by a client
response.disableCaching();
try
{
final StringResponse bodyResponse = new StringResponse();
responseObject.writeTo(bodyResponse, encoding);
CharSequence filteredResponse = invokeResponseFilters(bodyResponse);
response.write(filteredResponse);
}
finally
{
// restore the original response
rc.setResponse(response);
}
}
/**
* Runs the configured {@link IResponseFilter}s over the constructed Ajax response
*
* @param contentResponse
* the Ajax {@link Response} body
* @return filtered response
*/
private AppendingStringBuffer invokeResponseFilters(final StringResponse contentResponse)
{
AppendingStringBuffer responseBuffer = new AppendingStringBuffer(
contentResponse.getBuffer());
List<IResponseFilter> responseFilters = Application.get()
.getRequestCycleSettings()
.getResponseFilters();
if (responseFilters != null)
{
for (IResponseFilter filter : responseFilters)
{
responseBuffer = filter.filter(responseBuffer);
}
}
return responseBuffer;
}
/**
* @see java.lang.Object#toString()
*/
@Override
public String toString()
{
return "[AjaxRequestHandler@" + hashCode() + " responseObject [" + responseObject + "]";
}
@Override
public IHeaderResponse getHeaderResponse()
{
return responseObject.getHeaderResponse();
}
/**
* @return the markup id of the focused element in the browser
*/
@Override
public String getLastFocusedElementId()
{
WebRequest request = (WebRequest)page.getRequest();
String id = request.getHeader("Wicket-FocusedElementId");
return Strings.isEmpty(id) ? null : id;
}
/**
* @see org.apache.wicket.core.request.handler.IPageRequestHandler#getPageClass()
*/
@Override
public Class<? extends IRequestablePage> getPageClass()
{
return page.getPageClass();
}
/**
* @see org.apache.wicket.core.request.handler.IPageRequestHandler#getPageId()
*/
@Override
public Integer getPageId()
{
return page.getPageId();
}
/**
* @see org.apache.wicket.core.request.handler.IPageRequestHandler#getPageParameters()
*/
@Override
public PageParameters getPageParameters()
{
return page.getPageParameters();
}
@Override
public final boolean isPageInstanceCreated()
{
return true;
}
@Override
public final Integer getRenderCount()
{
return page.getRenderCount();
}
/** {@inheritDoc} */
@Override
public PageLogData getLogData()
{
return logData;
}
private void assertNotFrozen(boolean frozen, Class<?> clazz)
{
if (frozen)
{
throw new IllegalStateException(clazz.getSimpleName() + "s can no " +
" longer be added");
}
}
private void assertRespondersNotFrozen()
{
assertNotFrozen(respondersFrozen, AjaxRequestTarget.ITargetRespondListener.class);
}
private void assertListenersNotFrozen()
{
assertNotFrozen(listenersFrozen, AjaxRequestTarget.IListener.class);
}
}