| package org.apache.commons.digester3.substitution; |
| |
| /* |
| * 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.xml.sax.Attributes; |
| |
| import java.util.ArrayList; |
| |
| /** |
| * Wrapper for an {@link Attributes} object which expands any "variables" referenced in the attribute value via |
| * ${foo} or similar. This is only done when something actually asks for the attribute value, thereby imposing no |
| * performance penalty if the attribute is not used. |
| * |
| * @since 1.6 |
| */ |
| public class VariableAttributes |
| implements Attributes |
| { |
| |
| // list of mapped attributes. |
| private ArrayList<String> values = new ArrayList<String>( 10 ); |
| |
| private Attributes attrs; |
| |
| private VariableExpander expander; |
| |
| // ------------------- Public Methods |
| |
| /** |
| * Specify which attributes class this object is a proxy for. |
| * |
| * @param attrs The attributes where variables have to be expanded. |
| * @param expander The variables expander instance. |
| */ |
| public void init( Attributes attrs, VariableExpander expander ) |
| { |
| this.attrs = attrs; |
| this.expander = expander; |
| |
| // I hope this doesn't release the memory for this array; for |
| // efficiency, this should just mark the array as being size 0. |
| values.clear(); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public String getValue( int index ) |
| { |
| if ( index >= values.size() ) |
| { |
| // Expand the values array with null elements, so the later |
| // call to set(index, s) works ok. |
| // |
| // Unfortunately, there is no easy way to set the size of |
| // an arraylist; we must repeatedly add null elements to it.. |
| values.ensureCapacity( index + 1 ); |
| for ( int i = values.size(); i <= index; ++i ) |
| { |
| values.add( null ); |
| } |
| } |
| |
| String s = values.get( index ); |
| |
| if ( s == null ) |
| { |
| // we have never been asked for this value before. |
| // get the real attribute value and perform substitution |
| // on it. |
| s = attrs.getValue( index ); |
| if ( s != null ) |
| { |
| s = expander.expand( s ); |
| values.set( index, s ); |
| } |
| } |
| |
| return s; |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public String getValue( String qname ) |
| { |
| int index = attrs.getIndex( qname ); |
| if ( index == -1 ) |
| { |
| return null; |
| } |
| return getValue( index ); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public String getValue( String uri, String localname ) |
| { |
| int index = attrs.getIndex( uri, localname ); |
| if ( index == -1 ) |
| { |
| return null; |
| } |
| return getValue( index ); |
| } |
| |
| // plain proxy methods follow : nothing interesting :-) |
| /** |
| * {@inheritDoc} |
| */ |
| public int getIndex( String qname ) |
| { |
| return attrs.getIndex( qname ); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public int getIndex( String uri, String localpart ) |
| { |
| return attrs.getIndex( uri, localpart ); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public int getLength() |
| { |
| return attrs.getLength(); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public String getLocalName( int index ) |
| { |
| return attrs.getLocalName( index ); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public String getQName( int index ) |
| { |
| return attrs.getQName( index ); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public String getType( int index ) |
| { |
| return attrs.getType( index ); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public String getType( String qname ) |
| { |
| return attrs.getType( qname ); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public String getType( String uri, String localname ) |
| { |
| return attrs.getType( uri, localname ); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public String getURI( int index ) |
| { |
| return attrs.getURI( index ); |
| } |
| |
| } |