001    /*
002     * Jpkg - Java library and tools for operating system package creation.
003     *
004     * Copyright (c) 2007-2008 Three Rings Design, Inc.
005     * All rights reserved.
006     *
007     * Redistribution and use in source and binary forms, with or without
008     * modification, are permitted provided that the following conditions
009     * are met:
010     * 1. Redistributions of source code must retain the above copyright
011     *    notice, this list of conditions and the following disclaimer.
012     * 2. Redistributions in binary form must reproduce the above copyright
013     *    notice, this list of conditions and the following disclaimer in the
014     *    documentation and/or other materials provided with the distribution.
015     * 3. Neither the name of the copyright owner nor the names of contributors
016     *    may be used to endorse or promote products derived from this software
017     *    without specific prior written permission.
018     *
019     * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
020     * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
021     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
022     * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
023     * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
024     * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
025     * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
026     * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
027     * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
028     * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
029     * POSSIBILITY OF SUCH DAMAGE.
030     */
031    package com.threerings.jpkg.ant.dpkg.scripts;
032    
033    import java.io.ByteArrayInputStream;
034    import java.io.ByteArrayOutputStream;
035    import java.io.IOException;
036    import java.io.InputStream;
037    import java.io.OutputStreamWriter;
038    
039    import com.threerings.antidote.field.BaseField;
040    import com.threerings.jpkg.ant.VelocityHelper;
041    import com.threerings.jpkg.ant.VelocityTemplate;
042    import com.threerings.jpkg.ant.dpkg.scripts.runner.PackageScript;
043    
044    /**
045     * A {@link PackageScript} where the script source comes from a Velocity template.
046     * See {@link TemplateScript} for a useful subclass to extend from.
047     */
048    public abstract class BaseTemplateScript extends BaseField
049        implements ValidationScript, VelocityTemplate
050    {
051        /**
052         * Return an {@link InputStream} of the merged script template.
053         */
054        protected InputStream mergeTemplate ()
055            throws IOException
056        {
057            // write the template to memory
058            final ByteArrayOutputStream bytes = new ByteArrayOutputStream();
059    
060            final OutputStreamWriter writer = new OutputStreamWriter(bytes);
061            try {
062                VelocityHelper.mergeTemplate(this, writer);
063    
064            } catch (final Exception e) {
065                throw new IOException(e.getMessage());
066    
067            } finally {
068                writer.close();
069            }
070            return new ByteArrayInputStream(bytes.toByteArray());
071        }
072    }