// Copyright 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.corelib.components;
import java.util.List;
import org.apache.tapestry.ComponentResources;
import org.apache.tapestry.Link;
import org.apache.tapestry.MarkupWriter;
import org.apache.tapestry.annotations.Environmental;
import org.apache.tapestry.annotations.Inject;
import org.apache.tapestry.annotations.Parameter;
import org.apache.tapestry.services.PageRenderSupport;
/**
* Generates a render request link to some other page in the application. If an activation context
* is supplied (as the context parameter), then the context values will be encoded into the URL. If
* no context is supplied, then the target page itself will supply the context via a passivate
* event.
* <p>
* Pages are not required to have an activation context. When a page does have an activation
* context, the value typically represents the identity of some object displayed or otherwise
* manipulated by the page.
*/
public class PageLink
{
/** The logical name of the page to link to. */
@Parameter(required = true, defaultPrefix = "literal")
private String _page;
@Inject
private ComponentResources _resources;
@Environmental
private PageRenderSupport _support;
/**
* If provided, this is the activation context for the target page (the information will be
* encoded into the URL). If not provided, then the target page will provide its own activation
* context.
*/
@Parameter
private List _context;
private final Object[] _emptyContext = new Object[0];
void beginRender(MarkupWriter writer)
{
String clientId = _support.allocateClientId(_resources.getId());
Object[] activationContext = _context != null ? _context.toArray() : _emptyContext;
Link link = _resources.createPageLink(_page, activationContext);
writer.element("a", "href", link, "id", clientId);
_resources.renderInformalParameters(writer);
}
void afterRender(MarkupWriter writer)
{
writer.end(); // <a>
}
}