| package org.apache.commons.jelly.tags.velocity; |
| |
| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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. |
| */ |
| |
| import org.apache.commons.jelly.JellyTagException; |
| import org.apache.commons.jelly.XMLOutput; |
| |
| import org.apache.velocity.exception.MethodInvocationException; |
| import org.apache.velocity.exception.ParseErrorException; |
| import org.apache.velocity.exception.ResourceNotFoundException; |
| |
| import java.io.FileOutputStream; |
| import java.io.IOException; |
| import java.io.OutputStreamWriter; |
| import java.io.StringWriter; |
| import java.io.Writer; |
| |
| /** |
| * A tag that uses Velocity to render a specified template with the |
| * JellyContext storing the results in either a variable in the |
| * JellyContext or in a specified file. |
| * |
| * @author <a href="mailto:pete-apache-dev@kazmier.com">Pete Kazmier</a> |
| * @version $Id$ |
| */ |
| public class MergeTag extends VelocityTagSupport |
| { |
| private static final String ENCODING = "ISO-8859-1"; |
| |
| private String var; |
| private String name; |
| private String basedir; |
| private String template; |
| private String inputEncoding; |
| private String outputEncoding; |
| private boolean readOnly = true; |
| |
| // -- Tag interface ----------------------------------------------------- |
| |
| public void doTag( final XMLOutput output ) throws JellyTagException |
| { |
| if ( basedir == null || template == null ) |
| { |
| throw new JellyTagException( |
| "This tag must define 'basedir' and 'template'" ); |
| } |
| |
| if ( name != null ) |
| { |
| try { |
| Writer writer = new OutputStreamWriter( |
| new FileOutputStream( name ), |
| outputEncoding == null ? ENCODING : outputEncoding ); |
| mergeTemplate( writer ); |
| writer.close(); |
| } |
| catch (IOException e) { |
| throw new JellyTagException(e); |
| } |
| } |
| else if ( var != null ) |
| { |
| StringWriter writer = new StringWriter(); |
| mergeTemplate( writer ); |
| context.setVariable( var, writer.toString() ); |
| } |
| else |
| { |
| throw new JellyTagException( |
| "This tag must define either 'name' or 'var'" ); |
| } |
| } |
| |
| // -- Properties -------------------------------------------------------- |
| |
| /** |
| * Sets the var used to store the results of the merge. |
| * |
| * @param var The var to set in the JellyContext with the results of |
| * the merge. |
| */ |
| public void setVar( String var ) |
| { |
| this.var = var; |
| } |
| |
| /** |
| * Sets the file name for the merged output. |
| * |
| * @param name The name of the output file that is used to store the |
| * results of the merge. |
| */ |
| public void setName( String name ) |
| { |
| this.name = name; |
| } |
| |
| /** |
| * Sets the base directory used for loading of templates by the |
| * Velocity file resource loader. |
| * |
| * @param basedir The directory where templates can be located by |
| * the Velocity file resource loader. |
| */ |
| public void setBasedir( String basedir ) |
| { |
| this.basedir = basedir; |
| } |
| |
| /** |
| * Sets the filename of the template used to merge with the |
| * JellyContext. |
| * |
| * @param template The filename of the template to be merged. |
| */ |
| public void setTemplate( String template ) |
| { |
| this.template = template; |
| } |
| |
| /** |
| * Sets the read-only flag for this adapter which prevents |
| * modifications in the Velocity context from propagating to the |
| * JellyContext. |
| * |
| * @param readOnly <tt>true</tt> prevents modifications from |
| * propagating (the default), or <tt>false</tt> which permits |
| * modifications. |
| */ |
| public void setReadOnly( boolean readOnly ) |
| { |
| this.readOnly = readOnly; |
| } |
| |
| /** |
| * Sets the output encoding mode which defaults to ISO-8859-1 used |
| * when storing the results of a merge in a file. |
| * |
| * @param encoding The file encoding to use when writing the |
| * output. |
| */ |
| public void setOutputEncoding( String encoding ) |
| { |
| this.outputEncoding = encoding; |
| } |
| |
| /** |
| * Sets the input encoding used in the specified template which |
| * defaults to ISO-8859-1. |
| * |
| * @param encoding The encoding used in the template. |
| */ |
| public void setInputEncoding( String encoding ) |
| { |
| this.inputEncoding = encoding; |
| } |
| |
| // -- Implementation ---------------------------------------------------- |
| |
| /** |
| * Merges the Velocity template with the Jelly context. |
| * |
| * @param writer The output writer used to write the merged results. |
| * @throws Exception If an exception occurs during the merge. |
| */ |
| private void mergeTemplate( Writer writer ) throws JellyTagException |
| { |
| JellyContextAdapter adapter = new JellyContextAdapter( getContext() ); |
| adapter.setReadOnly( readOnly ); |
| |
| try { |
| getVelocityEngine( basedir ).mergeTemplate( |
| template, |
| inputEncoding == null ? ENCODING : inputEncoding, |
| adapter, |
| writer ); |
| } |
| catch (ResourceNotFoundException e) { |
| throw new JellyTagException(e); |
| } |
| catch (ParseErrorException e) { |
| throw new JellyTagException(e); |
| } |
| catch (MethodInvocationException e) { |
| throw new JellyTagException(e); |
| } |
| catch (Exception e) { |
| throw new JellyTagException(e); |
| } |
| } |
| } |
| |