// Copyright 2006, 2007 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.internal.services;
import static org.apache.tapestry.ioc.internal.util.CollectionFactory.newList;
import static org.apache.tapestry.ioc.internal.util.CollectionFactory.newMap;
import static org.apache.tapestry.ioc.internal.util.CollectionFactory.newThreadSafeList;
import static org.apache.tapestry.ioc.internal.util.Defense.notBlank;
import static org.apache.tapestry.ioc.internal.util.Defense.notNull;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import org.apache.tapestry.ComponentEventHandler;
import org.apache.tapestry.Link;
import org.apache.tapestry.TapestryConstants;
import org.apache.tapestry.internal.InternalConstants;
import org.apache.tapestry.internal.TapestryInternalUtils;
import org.apache.tapestry.internal.structure.ComponentPageElement;
import org.apache.tapestry.internal.structure.Page;
import org.apache.tapestry.ioc.services.TypeCoercer;
import org.apache.tapestry.ioc.util.StrategyRegistry;
import org.apache.tapestry.runtime.Component;
import org.apache.tapestry.services.Request;
import org.apache.tapestry.services.Response;
public class LinkFactoryImpl implements LinkFactory
{
private final Request _request;
private final Response _response;
private final ComponentInvocationMap _componentInvocationMap;
private final RequestPageCache _pageCache;
private final TypeCoercer _typeCoercer;
private final List<LinkFactoryListener> _listeners = newThreadSafeList();
private final StrategyRegistry<PassivateContextHandler> _registry;
private interface PassivateContextHandler<T>
{
void handle(T result, List context);
}
public LinkFactoryImpl(Request request, Response encoder,
ComponentInvocationMap componentInvocationMap,
RequestPageCache pageCache, TypeCoercer typeCoercer)
{
_request = request;
_response = encoder;
_componentInvocationMap = componentInvocationMap;
_pageCache = pageCache;
_typeCoercer = typeCoercer;
Map<Class, PassivateContextHandler> registrations = newMap();
registrations.put(Object.class, new PassivateContextHandler()
{
@SuppressWarnings("unchecked")
public void handle(Object result, List context)
{
context.add(result);
}
});
registrations.put(Object[].class, new PassivateContextHandler<Object[]>()
{
@SuppressWarnings("unchecked")
public void handle(Object[] result, List context)
{
for (Object o : result)
context.add(o);
}
});
registrations.put(Collection.class, new PassivateContextHandler<Collection>()
{
@SuppressWarnings("unchecked")
public void handle(Collection result, List context)
{
context.addAll(result);
}
});
_registry = StrategyRegistry.newInstance(PassivateContextHandler.class, registrations);
}
public void addListener(LinkFactoryListener listener)
{
_listeners.add(listener);
}
public Link createActionLink(ComponentPageElement component, String action, boolean forForm,
Object... context)
{
notBlank(action, "action");
Page containingPage = component.getContainingPage();
String logicalPageName = containingPage.getLogicalName();
ActionLinkTarget target = new ActionLinkTarget(action, logicalPageName, component
.getNestedId());
String[] contextStrings = toContextStrings(context);
String[] activationContext = collectActivationContextForPage(containingPage);
ComponentInvocation invocation = new ComponentInvocation(target, contextStrings,
activationContext);
Link link = new LinkImpl(_response, _request.getContextPath(), invocation, forForm);
// Now see if the page has an activation context.
addActivationContextToLink(link, activationContext);
// TODO: query parameter for case where active page != component page.
_componentInvocationMap.store(link, invocation);
for (LinkFactoryListener listener : _listeners)
listener.createdActionLink(link);
return link;
}
private void addActivationContextToLink(Link link, String[] activationContext)
{
if (activationContext.length == 0) return;
StringBuilder builder = new StringBuilder();
for (int i = 0; i < activationContext.length; i++)
{
if (i > 0) builder.append("/");
builder.append(TapestryInternalUtils.urlEncode(activationContext[i]));
}
link.addParameter(InternalConstants.PAGE_CONTEXT_NAME, builder.toString());
}
public Link createPageLink(final Page page, boolean override, Object... activationContext)
{
notNull(page, "page");
String logicalPageName = page.getLogicalName();
// When override is true, we use the activation context even if empty.
String[] context = (override || activationContext.length != 0) ? toContextStrings(activationContext)
: collectActivationContextForPage(page);
PageLinkTarget target = new PageLinkTarget(logicalPageName);
ComponentInvocation invocation = new ComponentInvocation(target, context, null);
Link link = new LinkImpl(_response, _request.getContextPath(), invocation, false);
_componentInvocationMap.store(link, invocation);
for (LinkFactoryListener listener : _listeners)
listener.createdPageLink(link);
return link;
}
/**
* Returns a list of objects acquired by invoking triggering the passivate event on the page's
* root element. May return an empty list.
*/
private String[] collectActivationContextForPage(final Page page)
{
final List context = newList();
ComponentEventHandler handler = new ComponentEventHandler()
{
@SuppressWarnings("unchecked")
public boolean handleResult(Object result, Component component, String methodDescription)
{
PassivateContextHandler contextHandler = _registry.getByInstance(result);
contextHandler.handle(result, context);
return true;
}
};
ComponentPageElement rootElement = page.getRootElement();
rootElement.triggerEvent(TapestryConstants.PASSIVATE_EVENT, null, handler);
return toContextStrings(context.toArray());
}
private String[] toContextStrings(Object[] context)
{
if (context == null) return new String[0];
String[] result = new String[context.length];
for (int i = 0; i < context.length; i++)
result[i] = _typeCoercer.coerce(context[i], String.class);
return result;
}
public Link createPageLink(String pageName, boolean override, Object... context)
{
// This verifies that the page name is valid.
Page page = _pageCache.get(pageName);
return createPageLink(page, override, context);
}
}