org.apache.myfaces.component.html.ext._SubIdConverter Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
Show all versions of tomahawk21 Show documentation
JSF components and utilities that can be used with any JSF implementation. This library is based on the JSF1.1 version of Tomahawk, but with minor source code and build changes to take advantage of JSF2.1 features. A JSF2.1 implementation is required to use this version of the Tomahawk library.
The newest version!
/*
 * 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.
 */
package org.apache.myfaces.component.html.ext;

import javax.faces.FacesException;

class _SubIdConverter
{
    private static final String HEX_CHARSET = "0123456789ABCDEF";
    
    /**
     * Encode the string into an html sub id valid value.  
     * 
     * An html id must comply with the following rules
     * 
     * 1. Must begin with a letter A-Z or a-z
     * 2. Can be followed by: letters (A-Za-z), digits (0-9), hyphens ("-"), underscores ("_"), colons (":"), and periods (".")
     * 3. Values are case-sensitive
     * 
     * The first rule is warranted because this convert an sub id, so a prefix is always added to
     * the returning string. The encoder converts all non valid chars into a unicode hex string prefixed with '_' char.
     * For example _ is converted to _005F, + is converted to _002B and so on.
     * 
     * @param string
     * @param characterEncoding
     * @return
     */
    public static String encode(final String string)
    {
        StringBuilder sb = null;    //create later on demand
        String app;
        char c;
        boolean endLoop = false;
        for (int i = 0; i < string.length (); ++i)
        {
            app = null;
            c = string.charAt(i);
            
            if (( c >= '0' && c <='9') || (c >='A' && c <='Z') || (c >='a' && c <='z')
                || c == ':' || c == '.' ) //|| c == '-' // '-' used to indicate rowIndex
            {
                //No encoding, just do nothing, char will be added later.
            }
            else
            {
                
                app = "_" + HEX_CHARSET.charAt( ((c >> 0x0C) % 0x10)) +  HEX_CHARSET.charAt( ((c >> 0x8) % 0x10)) + HEX_CHARSET.charAt( ((c >> 0x4) % 0x10)) +HEX_CHARSET.charAt(c % 0x10);
            }
                        
            if (app != null)
            {
                if (sb == null)
                {
                    sb = new StringBuilder(string.substring(0, i));
                }
                sb.append(app);
            } else {
                if (sb != null)
                {
                    sb.append(c);
                }
            }
            if (endLoop)
            {
                break;
            }
        }
        if (sb == null)
        {
            return string;
        }
        else
        {
            return sb.toString();
        }
    }

    public static String decode(final String string)
    {
        StringBuilder sb = null;    //create later on demand
        String app;
        char c;
        boolean endLoop = false;
        for (int i = 0; i < string.length (); ++i)
        {
            app = null;
            c = string.charAt(i);
            
            if (c == '_')
            {
                int value = (toDigit(string.charAt(i+1)) << 0x0C) + (toDigit(string.charAt(i+2)) << 0x08) + (toDigit(string.charAt(i+3)) << 0x04) + toDigit(string.charAt(i+4));
                
                if (sb == null)
                {
                    sb = new StringBuilder(string.substring(0, i));
                }
                i += 4;
                app = ""+((char)value);
            }
            else
            {
                //No decoding
            }

            if (app != null)
            {
                if (sb == null)
                {
                    sb = new StringBuilder(string.substring(0, i));
                }
                sb.append(app);
            } else {
                if (sb != null)
                {
                    sb.append(c);
                }
            }
            if (endLoop)
            {
                break;
            }
        }
        if (sb == null)
        {
            return string;
        }
        else
        {
            return sb.toString();
        }
    }
    
    /**
     * Converts a hexadecimal character to an integer.
     * 
     * @param ch
     *            A character to convert to an integer digit
     * @param index
     *            The index of the character in the source
     * @return An integer
     * @throws DecoderException
     *             Thrown if ch is an illegal hex character
     */
    protected static int toDigit(char ch)
    {
        int digit = Character.digit(ch, 16);
        if (digit == -1)
        {
            throw new FacesException("Illegal hexadecimal charcter ");
        }
        return digit;
    }
}