// Copyright Aug 2, 2006 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.html;
import org.apache.hivemind.ApplicationRuntimeException;
import org.apache.tapestry.AbstractComponent;
import org.apache.tapestry.IAsset;
import org.apache.tapestry.IMarkupWriter;
import org.apache.tapestry.IRequestCycle;
import org.apache.tapestry.markup.MarkupWriterSource;
import org.apache.tapestry.util.ContentType;
import java.io.PrintWriter;
import java.io.StringWriter;
/**
* Works with the {@link Shell} component to define and append a
* relationship between documents (typically a stylesheet) to
* the HTML response.
*
* @author Andreas Andreou
* @since 4.1.1
*/
public abstract class Relation extends AbstractComponent
{
/**
* {@inheritDoc}
*/
protected void renderComponent(IMarkupWriter writer, IRequestCycle cycle)
{
if (!cycle.isRewinding())
{
Shell shell = Shell.get(cycle);
if (shell == null)
throw new ApplicationRuntimeException(
HTMLMessages.shellComponentRequired(),
this.getLocation(), null);
if (getUseBody() && getHref() == null)
{
renderStyleTag(shell, writer, cycle);
}
else
{
renderLinkTag(shell, writer, cycle);
}
}
}
protected void renderLinkTag(Shell shell, IMarkupWriter writer, IRequestCycle cycle)
{
Object href = getHref();
boolean ok = (href instanceof String) || (href instanceof IAsset);
if (!ok)
throw new ApplicationRuntimeException(HTMLMessages.stringOrIAssetExpected(), getLocation(), null);
String url;
if (href instanceof String)
{
url = (String) href;
}
else
{
url = ((IAsset)href).buildURL();
}
RelationBean bean = new RelationBean();
bean.setHref(url);
bean.setMedia(getMedia());
bean.setRel(getRel());
bean.setRev(getRev());
bean.setTitle(getTitle());
bean.setType(getType());
shell.addRelation(bean);
}
protected void renderStyleTag(Shell shell, IMarkupWriter writer, IRequestCycle cycle)
{
if (getBody() == null) //nothing to include
{
return;
}
StringWriter sWriter = new StringWriter();
IMarkupWriter nested = getMarkupWriterSource().newMarkupWriter(new PrintWriter(sWriter),
new ContentType(writer.getContentType()));
nested.begin("style");
nested.attribute("type", "text/css");
if (getMedia()!=null)
nested.attribute("media", getMedia());
if (getTitle()!=null)
nested.attribute("title", getTitle());
renderBody(nested, cycle);
nested.close();
shell.includeAdditionalContent(sWriter.toString());
}
public abstract boolean getUseBody();
public abstract Object getHref();
public abstract String getRel();
public abstract String getRev();
public abstract String getType();
public abstract String getTitle();
public abstract String getMedia();
/* injected */
public abstract MarkupWriterSource getMarkupWriterSource();
}