NoTemplateEngine.java
/*
* $Source$
* $Revision$
*
* Copyright (C) 2000 Tim Joyce
*
* Part of Melati (http://melati.org), a framework for the rapid
* development of clean, maintainable web applications.
*
* Melati is free software; Permission is granted to copy, distribute
* and/or modify this software under the terms either:
*
* a) the GNU General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option)
* any later version,
*
* or
*
* b) any version of the Melati Software License, as published
* at http://melati.org
*
* You should have received a copy of the GNU General Public License and
* the Melati Software License along with this program;
* if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA to obtain the
* GNU General Public License and visit http://melati.org to obtain the
* Melati Software License.
*
* Feel free to contact the Developers of Melati (http://melati.org),
* if you would like to work out a different arrangement than the options
* outlined here. It is our intention to allow Melati to be used by as
* wide an audience as possible.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* Contact details for copyright holder:
*
* Tim Joyce <timj At paneris.org>
* http://paneris.org/
* 68 Sandbanks Rd, Poole, Dorset. BH14 8BY. UK
*/
package org.melati.template;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServlet;
import org.melati.Melati;
import org.melati.MelatiConfig;
import org.melati.util.MelatiIOException;
import org.melati.util.MelatiWriter;
import org.melati.util.MelatiSimpleWriter;
import org.melati.util.MelatiStringWriter;
import org.melati.util.MelatiBufferedWriter;
/**
* The <code>null</code> {@link ServletTemplateEngine}.
*
* @author Tim Joyce
*/
public class NoTemplateEngine extends AbstractTemplateEngine implements ServletTemplateEngine {
private String message =
"No Template engine is Configured, please specify an engine in " +
"org.melati.MelatiConfig.properties";
/**
* Constructor.
*/
public NoTemplateEngine() {
super();
}
/**
* Construct a null Engine.
*
* @param config a {@link MelatiConfig}
*/
public void init(MelatiConfig config) {
// we don't throw an exception here as it gets hidden away, rather
// it is better to wait until expandTemplate or getParameters, as
// that produces a nice
// exception to the browser
}
/**
* Construct a new Engine for use in a servlet environment.
*
* @see org.melati.servlet.TemplateServlet
* @param melatiConfig a {@link MelatiConfig}
* @param servlet the servlet we are within
* @throws TemplateEngineException if any problem occurs with the engine
*/
public void init(MelatiConfig melatiConfig, HttpServlet servlet)
throws TemplateEngineException {
init(melatiConfig);
}
/**
* Throw exception.
*
* @throws TemplateEngineException if any problem occurs with the engine
* @return a {@link TemplateContext}
*/
public TemplateContext getTemplateContext()
throws TemplateEngineException {
throw new TemplateEngineException(message);
}
/**
* Throw exception.
*
* @param melati the {@link Melati}
* @throws TemplateEngineException always
* @return an exception
*/
public ServletTemplateContext getServletTemplateContext(Melati melati)
throws TemplateEngineException {
throw new TemplateEngineException(message);
}
/**
* The name of the template engine (used to find the templets).
* @return the name of the current configured template engine
*/
public String getName() {
return "none";
}
/**
* @return the extension of the templates used by this template engine
*/
public String templateExtension() {
return ".none";
}
/**
* Get a template given its name.
*
* @param templateName the name of the template to find
* @return a template
*/
public Template template(String templateName) {
throw new TemplateEngineException(
"The template " +
templateName + " could not be found because you have not configured a template engine.");
}
/**
* Expand the Template against the context.
*
* @param out a {@link MelatiWriter} to output on
* @param templateName the name of the template to expand
* @param templateContext the {@link ServletTemplateContext} to expand
* the template against
* @throws TemplateEngineException if invoked
*/
public void expandTemplate(MelatiWriter out, String templateName,
TemplateContext templateContext)
throws TemplateEngineException {
throw new TemplateEngineException(message);
}
/**
* Expand the Template against the context.
*
* @param out a {@link MelatiWriter} to output on
* @param melatiTemplate the {@link Template} to expand
* @param templateContext the {@link ServletTemplateContext} to expand
* the template against
* @throws TemplateEngineException if invoked
*/
public void expandTemplate(MelatiWriter out, Template melatiTemplate,
TemplateContext templateContext)
throws TemplateEngineException {
throw new TemplateEngineException(message);
}
/**
* Expand the Template against the context.
*
* @param melatiTemplate the {@link Template} to expand
* @param templateContext the {@link ServletTemplateContext} to expand
* the template against
* @throws TemplateEngineException if invoked
* {@inheritDoc}
* @see org.melati.template.TemplateEngine#expandedTemplate
* (org.melati.template.Template, org.melati.template.TemplateContext)
*/
public String expandedTemplate(Template melatiTemplate,
TemplateContext templateContext)
throws TemplateEngineException {
throw new TemplateEngineException(message);
}
/**
* @param response the <code>HttpServletResponse</code> that this
* writer will be part of
* @param buffered whether the writer should be buffered
* @return a {@link MelatiWriter}
* appropriate for this engine.
*/
public MelatiWriter getServletWriter(HttpServletResponse response,
boolean buffered) {
PrintWriter printWriter = null;
try {
printWriter = response.getWriter();
} catch (IOException e) {
throw new MelatiIOException(e);
}
if (buffered)
return new MelatiBufferedWriter(printWriter);
else
return new MelatiSimpleWriter(printWriter);
}
/**
* Return a {@link MelatiStringWriter}.
* {@inheritDoc}
* @see org.melati.template.TemplateEngine#getStringWriter()
* @see Melati#getStringWriter()
*/
public MelatiStringWriter getStringWriter() {
return new MelatiStringWriter();
}
/**
* Get the underlying engine.
*
* @return 'none'
*/
public Object getEngine() {
return "none";
}
}