| package org.apache.velocity; |
| |
| /* |
| * The Apache Software License, Version 1.1 |
| * |
| * Copyright (c) 2000-2001 The Apache Software Foundation. All rights |
| * reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * 3. The end-user documentation included with the redistribution, if |
| * any, must include the following acknowlegement: |
| * "This product includes software developed by the |
| * Apache Software Foundation (http://www.apache.org/)." |
| * Alternately, this acknowlegement may appear in the software itself, |
| * if and wherever such third-party acknowlegements normally appear. |
| * |
| * 4. The names "The Jakarta Project", "Velocity", and "Apache Software |
| * Foundation" must not be used to endorse or promote products derived |
| * from this software without prior written permission. For written |
| * permission, please contact apache@apache.org. |
| * |
| * 5. Products derived from this software may not be called "Apache" |
| * nor may "Apache" appear in their names without prior written |
| * permission of the Apache Group. |
| * |
| * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
| * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR |
| * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
| * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| * ==================================================================== |
| * |
| * This software consists of voluntary contributions made by many |
| * individuals on behalf of the Apache Software Foundation. For more |
| * information on the Apache Software Foundation, please see |
| * <http://www.apache.org/>. |
| */ |
| |
| import java.io.InputStream; |
| import java.io.IOException; |
| import java.io.Writer; |
| import java.io.BufferedReader; |
| import java.io.InputStreamReader; |
| import java.io.UnsupportedEncodingException; |
| |
| import org.apache.velocity.runtime.resource.Resource; |
| import org.apache.velocity.runtime.parser.ParseException; |
| import org.apache.velocity.runtime.parser.node.SimpleNode; |
| |
| import org.apache.velocity.VelocityContext; |
| import org.apache.velocity.context.Context; |
| import org.apache.velocity.context.InternalContextAdapter; |
| import org.apache.velocity.context.InternalContextAdapterImpl; |
| |
| import org.apache.velocity.exception.ResourceNotFoundException; |
| import org.apache.velocity.exception.ParseErrorException; |
| import org.apache.velocity.exception.MethodInvocationException; |
| |
| /** |
| * This class is used for controlling all template |
| * operations. This class uses a parser created |
| * by JavaCC to create an AST that is subsequently |
| * traversed by a Visitor. |
| * |
| * <pre> |
| * Template template = Velocity.getTemplate("test.wm"); |
| * Context context = new VelocityContext(); |
| * |
| * context.put("foo", "bar"); |
| * context.put("customer", new Customer()); |
| * |
| * template.merge(context, writer); |
| * </pre> |
| * |
| * @author <a href="mailto:jvanzyl@periapt.com">Jason van Zyl</a> |
| * @author <a href="mailto:geirm@optonline.net">Geir Magnusson Jr.</a> |
| * @version $Id: Template.java,v 1.34 2001/08/07 22:20:03 geirm Exp $ |
| */ |
| public class Template extends Resource |
| { |
| /** |
| * To keep track of whether this template has been |
| * initialized. We use the document.init(context) |
| * to perform this. |
| */ |
| private boolean initialized = false; |
| |
| private Exception errorCondition = null; |
| |
| /** Default constructor */ |
| public Template() |
| { |
| } |
| |
| /** |
| * gets the named resource as a stream, parses and inits |
| * |
| * @return true if successful |
| * @throws ResourceNotFoundException if template not found |
| * from any available source. |
| * @throws ParseErrorException if template cannot be parsed due |
| * to syntax (or other) error. |
| * @throws Exception some other problem, should only be from |
| * initialization of the template AST. |
| */ |
| public boolean process() |
| throws ResourceNotFoundException, ParseErrorException, Exception |
| { |
| data = null; |
| InputStream is = null; |
| errorCondition = null; |
| |
| /* |
| * first, try to get the stream from the loader |
| */ |
| try |
| { |
| is = resourceLoader.getResourceStream(name); |
| } |
| catch( ResourceNotFoundException rnfe ) |
| { |
| /* |
| * remember and re-throw |
| */ |
| |
| errorCondition = rnfe; |
| throw rnfe; |
| } |
| |
| /* |
| * if that worked, lets protect in case a loader impl |
| * forgets to throw a proper exception |
| */ |
| |
| if (is != null) |
| { |
| /* |
| * now parse the template |
| */ |
| |
| try |
| { |
| BufferedReader br = new BufferedReader( new InputStreamReader( is, encoding ) ); |
| |
| data = rsvc.parse( br, name); |
| initDocument(); |
| return true; |
| } |
| catch( UnsupportedEncodingException uce ) |
| { |
| String msg = "Template.process : Unsupported input encoding : " + encoding |
| + " for template " + name; |
| |
| errorCondition = new ParseErrorException( msg ); |
| throw errorCondition; |
| } |
| catch ( ParseException pex ) |
| { |
| /* |
| * remember the error and convert |
| */ |
| |
| errorCondition = new ParseErrorException( pex.getMessage() ); |
| throw errorCondition; |
| } |
| catch( Exception e ) |
| { |
| /* |
| * who knows? Something from initDocument() |
| */ |
| |
| errorCondition = e; |
| throw e; |
| } |
| finally |
| { |
| /* |
| * Make sure to close the inputstream when we are done. |
| */ |
| is.close(); |
| } |
| } |
| else |
| { |
| /* |
| * is == null, therefore we have some kind of file issue |
| */ |
| |
| errorCondition = new ResourceNotFoundException("Unknown resource error for resource " + name ); |
| throw errorCondition; |
| } |
| } |
| |
| /** |
| * initializes the document. init() is not longer |
| * dependant upon context, but we need to let the |
| * init() carry the template name down throught for VM |
| * namespace features |
| */ |
| public void initDocument() |
| throws Exception |
| { |
| /* |
| * send an empty InternalContextAdapter down into the AST to initialize it |
| */ |
| |
| InternalContextAdapterImpl ica = new InternalContextAdapterImpl( new VelocityContext() ); |
| |
| try |
| { |
| /* |
| * put the current template name on the stack |
| */ |
| |
| ica.pushCurrentTemplateName( name ); |
| |
| /* |
| * init the AST |
| */ |
| |
| ((SimpleNode)data).init( ica, rsvc); |
| } |
| finally |
| { |
| /* |
| * in case something blows up... |
| * pull it off for completeness |
| */ |
| |
| ica.popCurrentTemplateName(); |
| } |
| |
| } |
| |
| /** |
| * The AST node structure is merged with the |
| * context to produce the final output. |
| * |
| * Throws IOException if failure is due to a file related |
| * issue, and Exception otherwise |
| * |
| * @param context Conext with data elements accessed by template |
| * @param writer output writer for rendered template |
| * @throws ResourceNotFoundException if template not found |
| * from any available source. |
| * @throws ParseErrorException if template cannot be parsed due |
| * to syntax (or other) error. |
| * @throws Exception anything else. |
| */ |
| public void merge( Context context, Writer writer) |
| throws ResourceNotFoundException, ParseErrorException, MethodInvocationException, Exception |
| { |
| /* |
| * we shouldn't have to do this, as if there is an error condition, |
| * the application code should never get a reference to the |
| * Template |
| */ |
| |
| if (errorCondition != null) |
| { |
| throw errorCondition; |
| } |
| |
| if( data != null) |
| { |
| /* |
| * create an InternalContextAdapter to carry the user Context down |
| * into the rendering engine. Set the template name and render() |
| */ |
| |
| InternalContextAdapterImpl ica = new InternalContextAdapterImpl( context ); |
| |
| try |
| { |
| ica.pushCurrentTemplateName( name ); |
| ica.setCurrentResource( this ); |
| |
| ( (SimpleNode) data ).render( ica, writer); |
| } |
| finally |
| { |
| /* |
| * lets make sure that we always clean up the context |
| */ |
| ica.popCurrentTemplateName(); |
| ica.setCurrentResource( null ); |
| } |
| } |
| else |
| { |
| /* |
| * this shouldn't happen either, but just in case. |
| */ |
| |
| String msg = "Template.merge() failure. The document is null, " + |
| "most likely due to parsing error."; |
| |
| rsvc.error(msg); |
| throw new Exception(msg); |
| } |
| } |
| } |
| |
| |
