/src/solidstack/template/groovy/GroovyConvertingWriter.java

  1/*--
  2 * Copyright 2012 René M. de Bloois
  3 *
  4 * Licensed under the Apache License, Version 2.0 (the "License");
  5 * you may not use this file except in compliance with the License.
  6 * You may obtain a copy of the License at
  7 *
  8 *     http://www.apache.org/licenses/LICENSE-2.0
  9 *
 10 * Unless required by applicable law or agreed to in writing, software
 11 * distributed under the License is distributed on an "AS IS" BASIS,
 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 13 * See the License for the specific language governing permissions and
 14 * limitations under the License.
 15 */
 16
 17package solidstack.template.groovy;
 18
 19import groovy.lang.Closure;
 20import groovy.lang.GString;
 21
 22import java.io.IOException;
 23
 24import org.codehaus.groovy.runtime.InvokerHelper;
 25
 26import solidstack.template.ConvertingWriter;
 27import solidstack.template.EncodingWriter;
 28import solidstack.template.TemplateException;
 29
 30
 31/**
 32 * A ConvertingWriter that converts Groovy specific data types to Java data types.
 33 *
 34 * @author René de Bloois
 35 */
 36public class GroovyConvertingWriter implements ConvertingWriter
 37{
 38	/**
 39	 * The EncodingWriter to write to.
 40	 */
 41	protected EncodingWriter writer;
 42
 43	/**
 44	 * Constructor.
 45	 *
 46	 * @param writer The EncodingWriter to write to.
 47	 */
 48	public GroovyConvertingWriter( EncodingWriter writer )
 49	{
 50		this.writer = writer;
 51	}
 52
 53	public void write( Object o ) throws IOException
 54	{
 55		if( o == null )
 56			this.writer.write( null );
 57		else if( o instanceof String )
 58			this.writer.write( (String)o );
 59		else if( o instanceof GString )
 60		{
 61			GString gString = (GString)o;
 62			String[] strings = gString.getStrings();
 63			Object[] values = gString.getValues();
 64			if( !( strings.length == values.length + 1 ) )
 65				throw new IllegalStateException();
 66
 67			for( int i = 0; i < values.length; i++ )
 68			{
 69				this.writer.write( strings[ i ] );
 70				writeEncoded( values[ i ] );
 71			}
 72			this.writer.write( strings[ values.length ] );
 73		}
 74		else if( o instanceof Closure )
 75		{
 76			Closure c = (Closure)o;
 77			int pars = c.getMaximumNumberOfParameters();
 78			if( pars > 0 )
 79				throw new TemplateException( "Closures with parameters are not supported in expressions." );
 80			write( c.call() ); // May be recursive
 81		}
 82		else
 83			this.writer.write( (String)InvokerHelper.invokeMethod( o, "asType", String.class ) );
 84	}
 85
 86	public void writeEncoded( Object o ) throws IOException
 87	{
 88		if( o == null )
 89			this.writer.writeEncoded( null );
 90		else if( o instanceof String )
 91			this.writer.writeEncoded( o );
 92		else if( o instanceof GString )
 93			this.writer.writeEncoded( o.toString() );
 94		else if( o instanceof Closure )
 95		{
 96			Closure c = (Closure)o;
 97			int pars = c.getMaximumNumberOfParameters();
 98			if( pars > 0 )
 99				throw new TemplateException( "Closures with parameters are not supported in expressions." );
100			writeEncoded( c.call() ); // May be recursive
101		}
102		else
103		{
104			if( this.writer.stringsOnly() )
105				this.writer.writeEncoded( InvokerHelper.invokeMethod( o, "asType", String.class ) );
106			else
107				this.writer.writeEncoded( o );
108		}
109	}
110
111	public void flush() throws IOException
112	{
113		this.writer.flush();
114	}
115}