// Copyright 2006, 2007, 2008 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 org.apache.tapestry.EventContext;
import org.apache.tapestry.TapestryConstants;
import org.apache.tapestry.internal.EmptyEventContext;
import org.apache.tapestry.internal.InternalConstants;
import org.apache.tapestry.internal.TapestryInternalUtils;
import org.apache.tapestry.internal.URLEventContext;
import org.apache.tapestry.services.*;
import java.io.IOException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* Processes component action events sent as requests from the client. Action events include an event type, identify a
* page and a component, and may provide additional context strings.
* <p/>
* Forms: <ul> <li>/context/pagename:eventname -- event on the page, no action context</li>
* <li>/context/pagename:eventname/foo/bar -- event on the page with action context "foo", "bar"</li>
* <li>/context/pagename.foo.bar -- event on component foo.bar within the page, default event, no action context</li>
* <li>/context/pagename.foo.bar/baz.gnu -- event on component foo.bar within the page, default event, with action
* context "baz", "gnu"</li> <li>/context/pagename.bar.baz:eventname/foo/gnu -- event on component bar.baz within the
* page with action context "foo" , "gnu"</li> </ul>
* <p/>
* The page name portion may itself consist of a series of folder names, i.e., "admin/user/create". The context portion
* isn't the concern of this code, since {@link org.apache.tapestry.services.Request#getPath()} will already have
* stripped that off. We can act as if the context is always "/" (the path always starts with a slash).
*
* @see LinkFactory#createActionLink(org.apache.tapestry.internal.structure.Page, String, String,boolean, Object...)
*/
public class ComponentEventDispatcher implements Dispatcher
{
private final ComponentClassResolver _componentClassResolver;
private final ComponentEventRequestHandler _componentEventRequestHandler;
private final ContextValueEncoder _contextValueEncoder;
private final RequestEncodingInitializer _requestEncodingInitializer;
private final EventContext _emptyContext = new EmptyEventContext();
public ComponentEventDispatcher(@Traditional ComponentEventRequestHandler componentEventRequestHandler,
ComponentClassResolver componentClassResolver,
ContextValueEncoder contextValueEncoder,
RequestEncodingInitializer requestEncodingInitializer)
{
_componentEventRequestHandler = componentEventRequestHandler;
_componentClassResolver = componentClassResolver;
_contextValueEncoder = contextValueEncoder;
_requestEncodingInitializer = requestEncodingInitializer;
}
// A beast that recognizes all the elements of a path in a single go.
// We skip the leading slash, then take the next few terms (until a dot or a colon)
// as the page name. Then there's a sequence that sees a dot
// and recognizes the nested component id (which may be missing), which ends
// at the colon, or at the slash (or the end of the string). The colon identifies
// the event name (the event name is also optional). A valid path will always have
// a nested component id or an event name (or both) ... when both are missing, then the
// path is most likely a page render request. After the optional event name,
// the next piece is the action context, which is the remainder of the path.
private final Pattern PATH_PATTERN = Pattern.compile(
"^/" + // The leading slash is recognized but skipped
"(((\\w+)/)*(\\w+))" + // A series of folder names leading up to the page name, forming the logical page name
"(\\.(\\w+(\\.\\w+)*))?" + // The first dot separates the page name from the nested component id
"(\\:(\\w+))?" + // A colon, then the event type
"(/(.*))?", // A slash, then the action context
Pattern.COMMENTS);
// Constants for the match groups in the above pattern.
private static final int LOGICAL_PAGE_NAME = 1;
private static final int NESTED_ID = 6;
private static final int EVENT_NAME = 9;
private static final int CONTEXT = 11;
public boolean dispatch(Request request, Response response) throws IOException
{
Matcher matcher = PATH_PATTERN.matcher(request.getPath());
if (!matcher.matches()) return false;
String activePageName = matcher.group(LOGICAL_PAGE_NAME);
String nestedComponentId = matcher.group(NESTED_ID);
String eventType = matcher.group(EVENT_NAME);
if (nestedComponentId == null && eventType == null) return false;
if (!_componentClassResolver.isPageName(activePageName)) return false;
EventContext eventContext = decodeContext(matcher.group(CONTEXT));
// Initialize the request encoding BEFORE accessing any query parameters
// (TAPESTRY-1605)
_requestEncodingInitializer.initializeRequestEncoding(activePageName);
EventContext activationContext = decodeContext(request.getParameter(InternalConstants.PAGE_CONTEXT_NAME));
// The event type is often omitted, and defaults to "action".
if (eventType == null) eventType = TapestryConstants.ACTION_EVENT;
if (nestedComponentId == null) nestedComponentId = "";
String containingPageName = request.getParameter(InternalConstants.CONTAINER_PAGE_NAME);
if (containingPageName == null) containingPageName = activePageName;
ComponentEventRequestParameters parameters = new ComponentEventRequestParameters(activePageName,
containingPageName,
nestedComponentId, eventType,
activationContext,
eventContext);
_componentEventRequestHandler.handle(parameters);
return true;
}
private EventContext decodeContext(String input)
{
if (input == null) return _emptyContext;
String[] values = TapestryInternalUtils.splitPath(input);
for (int i = 0; i < values.length; i++)
{
values[i] = TapestryInternalUtils.unescapePercentAndSlash(values[i]);
}
return new URLEventContext(_contextValueEncoder, values);
}
}