/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* Licensed 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.
*/
/*
* $Id: ExsltStrings.java,v 1.15 2004/02/11 17:56:36 minchau Exp $
*/
package com.sun.org.apache.xalan.internal.lib;
import java.util.StringTokenizer;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.FactoryConfigurationError;
import javax.xml.parsers.ParserConfigurationException;
import com.sun.org.apache.xpath.internal.NodeSet;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;
/**
* This class contains EXSLT strings extension functions.
*
* It is accessed by specifying a namespace URI as follows:
* <pre>
* xmlns:str="http://exslt.org/strings"
* </pre>
* The documentation for each function has been copied from the relevant
* EXSLT Implementer page.
*
* @see <a href="http://www.exslt.org/">EXSLT</a>
* @xsl.usage general
*/
public class ExsltStrings extends ExsltBase
{
/**
* The str:align function aligns a string within another string.
* <p>
* The first argument gives the target string to be aligned. The second argument gives
* the padding string within which it is to be aligned.
* <p>
* If the target string is shorter than the padding string then a range of characters
* in the padding string are repaced with those in the target string. Which characters
* are replaced depends on the value of the third argument, which gives the type of
* alignment. It can be one of 'left', 'right' or 'center'. If no third argument is
* given or if it is not one of these values, then it defaults to left alignment.
* <p>
* With left alignment, the range of characters replaced by the target string begins
* with the first character in the padding string. With right alignment, the range of
* characters replaced by the target string ends with the last character in the padding
* string. With center alignment, the range of characters replaced by the target string
* is in the middle of the padding string, such that either the number of unreplaced
* characters on either side of the range is the same or there is one less on the left
* than there is on the right.
* <p>
* If the target string is longer than the padding string, then it is truncated to be
* the same length as the padding string and returned.
*
* @param targetStr The target string
* @param paddingStr The padding string
* @param type The type of alignment
*
* @return The string after alignment
*/
public static String align(String targetStr, String paddingStr, String type)
{
if (targetStr.length() >= paddingStr.length())
return targetStr.substring(0, paddingStr.length());
if (type.equals("right"))
{
return paddingStr.substring(0, paddingStr.length() - targetStr.length()) + targetStr;
}
else if (type.equals("center"))
{
int startIndex = (paddingStr.length() - targetStr.length()) / 2;
return paddingStr.substring(0, startIndex) + targetStr + paddingStr.substring(startIndex + targetStr.length());
}
// Default is left
else
{
return targetStr + paddingStr.substring(targetStr.length());
}
}
/**
* See above
*/
public static String align(String targetStr, String paddingStr)
{
return align(targetStr, paddingStr, "left");
}
/**
* The str:concat function takes a node set and returns the concatenation of the
* string values of the nodes in that node set. If the node set is empty, it returns
* an empty string.
*
* @param nl A node set
* @return The concatenation of the string values of the nodes in that node set
*/
public static String concat(NodeList nl)
{
StringBuffer sb = new StringBuffer();
for (int i = 0; i < nl.getLength(); i++)
{
Node node = nl.item(i);
String value = toString(node);
if (value != null && value.length() > 0)
sb.append(value);
}
return sb.toString();
}
/**
* The str:padding function creates a padding string of a certain length.
* The first argument gives the length of the padding string to be created.
* The second argument gives a string to be used to create the padding. This
* string is repeated as many times as is necessary to create a string of the
* length specified by the first argument; if the string is more than a character
* long, it may have to be truncated to produce the required length. If no second
* argument is specified, it defaults to a space (' '). If the second argument is
* an empty string, str:padding returns an empty string.
*
* @param length The length of the padding string to be created
* @param pattern The string to be used as pattern
*
* @return A padding string of the given length
*/
public static String padding(double length, String pattern)
{
if (pattern == null || pattern.length() == 0)
return "";
StringBuffer sb = new StringBuffer();
int len = (int)length;
int numAdded = 0;
int index = 0;
while (numAdded < len)
{
if (index == pattern.length())
index = 0;
sb.append(pattern.charAt(index));
index++;
numAdded++;
}
return sb.toString();
}
/**
* See above
*/
public static String padding(double length)
{
return padding(length, " ");
}
/**
* The str:split function splits up a string and returns a node set of token
* elements, each containing one token from the string.
* <p>
* The first argument is the string to be split. The second argument is a pattern
* string. The string given by the first argument is split at any occurrence of
* this pattern. For example:
* <pre>
* str:split('a, simple, list', ', ') gives the node set consisting of:
*
* <token>a</token>
* <token>simple</token>
* <token>list</token>
* </pre>
* If the second argument is omitted, the default is the string ' ' (i.e. a space).
*
* @param str The string to be split
* @param pattern The pattern
*
* @return A node set of split tokens
*/
public static NodeList split(String str, String pattern)
{
NodeSet resultSet = new NodeSet();
resultSet.setShouldCacheNodes(true);
boolean done = false;
int fromIndex = 0;
int matchIndex = 0;
String token = null;
while (!done && fromIndex < str.length())
{
matchIndex = str.indexOf(pattern, fromIndex);
if (matchIndex >= 0)
{
token = str.substring(fromIndex, matchIndex);
fromIndex = matchIndex + pattern.length();
}
else
{
done = true;
token = str.substring(fromIndex);
}
Document doc = DocumentHolder.m_doc;
synchronized (doc)
{
Element element = doc.createElement("token");
Text text = doc.createTextNode(token);
element.appendChild(text);
resultSet.addNode(element);
}
}
return resultSet;
}
/**
* See above
*/
public static NodeList split(String str)
{
return split(str, " ");
}
/**
* The str:tokenize function splits up a string and returns a node set of token
* elements, each containing one token from the string.
* <p>
* The first argument is the string to be tokenized. The second argument is a
* string consisting of a number of characters. Each character in this string is
* taken as a delimiting character. The string given by the first argument is split
* at any occurrence of any of these characters. For example:
* <pre>
* str:tokenize('2001-06-03T11:40:23', '-T:') gives the node set consisting of:
*
* <token>2001</token>
* <token>06</token>
* <token>03</token>
* <token>11</token>
* <token>40</token>
* <token>23</token>
* </pre>
* If the second argument is omitted, the default is the string '
'
* (i.e. whitespace characters).
* <p>
* If the second argument is an empty string, the function returns a set of token
* elements, each of which holds a single character.
* <p>
* Note: This one is different from the tokenize extension function in the Xalan
* namespace. The one in Xalan returns a set of Text nodes, while this one wraps
* the Text nodes inside the token Element nodes.
*
* @param toTokenize The string to be tokenized
* @param delims The delimiter string
*
* @return A node set of split token elements
*/
public static NodeList tokenize(String toTokenize, String delims)
{
NodeSet resultSet = new NodeSet();
if (delims != null && delims.length() > 0)
{
StringTokenizer lTokenizer = new StringTokenizer(toTokenize, delims);
Document doc = DocumentHolder.m_doc;
synchronized (doc)
{
while (lTokenizer.hasMoreTokens())
{
Element element = doc.createElement("token");
element.appendChild(doc.createTextNode(lTokenizer.nextToken()));
resultSet.addNode(element);
}
}
}
// If the delimiter is an empty string, create one token Element for
// every single character.
else
{
Document doc = DocumentHolder.m_doc;
synchronized (doc)
{
for (int i = 0; i < toTokenize.length(); i++)
{
Element element = doc.createElement("token");
element.appendChild(doc.createTextNode(toTokenize.substring(i, i+1)));
resultSet.addNode(element);
}
}
}
return resultSet;
}
/**
* See above
*/
public static NodeList tokenize(String toTokenize)
{
return tokenize(toTokenize, " \t\n\r");
}
/**
* This class is not loaded until first referenced (see Java Language
* Specification by Gosling/Joy/Steele, section 12.4.1)
*
* The static members are created when this class is first referenced, as a
* lazy initialization not needing checking against null or any
* synchronization.
*
*/
private static class DocumentHolder
{
// Reuse the Document object to reduce memory usage.
private static final Document m_doc;
static {
try
{
m_doc =DocumentBuilderFactory.newInstance().newDocumentBuilder().newDocument();
}
catch(ParserConfigurationException pce)
{
throw new com.sun.org.apache.xml.internal.utils.WrappedRuntimeException(pce);
}
}
}
}
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