EncodeXXX context tools [was Re: Rendering Velocity Templates with Texen]

[Christoph Reck <Ch...@dlr.de>]

"Geir Magnusson Jr." wrote:
> 
> Christoph Reck wrote:
> >
> > Yep, it does not work with Vel.
> > It does with WM (round instead of curlies).
> >
> > Well, this seems to be a devlish candidate for the parser tests...
> >
> > #set $D = "$"
> > is \$D == ${D}D OK?
> 
> If you can type it, Vel should parse it!  That's the rule. :)

Well it currently throuws a TokenMgrError: Lexical error at line 1, 
column 2.  Encountered: <EOF> after : "".

I saw you posted that you'll fix it.

> 
> Hey!  Where are your ( and ) in your #set() ?  Don't fill your logs with
> deprecation messages! ;->

Well; I've not yet moved to Vel, due to shortcomings/bugs...
Has the #set($foo = $somethingReturningNull) been fixed to clear/remove
foo? Shall we allow #set($hashtable.KEY = "value") Shall I provide the 
patches? No votes to my proposals yet...

> 
> > :P Christoph
> >
> > P.S. I have a ContextTool with formEncode, formDecode, encodeMarkup,
> >      and URLEncode. So I can do: #set $D = $Context.formDecode("%24")
> >      :)
> 
> That would be cool to have.  Wanna contribute it?

Code is below, could/should be added to the VelocityFormatter.

> 
> (The parser will be fixed though :)

Good

>[snip]

Some other methods are also included which go in the line of the
alternator...
--------------------------- cut here --------------------------
    /**
     * Translates a string into <code>x-www-form-urlencoded</code> format.
     * This method is just a wrapper to java.net.URLEncoder.encode().
     *
     * @param str The string to encode.
     * @return The URL-encoded string.
     * @see java.net.URLEncoder
     */
    public static String URLEncode(String str)
    {
        if (str == null)
            return  null;
        return URLEncoder.encode(str);
    }

    /**
     * Encode the characters &lt;, &gt;, &quot; and &amp to
     * &amp;lt;, &amp;gt;, &amp;quot, &amp;amp; respectively.
     * <code>&lt;input type="text" value="$formater.encodeMarkup($anyText)"&gt;</code>
     *
     * @param text The string to encode.
     * @return The HTML encoded string.
     */
    public static String encodeMarkup(String text)
    {
        char[] array = text.toCharArray();
        StringBuffer buffer = new StringBuffer();

        for (int i = 0; i < array.length; i++) {
            switch (array[i]) {
              case '<':
                buffer.append("&lt;");
                break;
              case'>':
                buffer.append("&gt;");
                break;
              case '&':
                buffer.append("&amp;");
                break;
              case '"':
                buffer.append("&quot;");
                break;
              default:
                buffer.append(array[i]);
                break;
            }
        }

        return buffer.toString();
    }

    /**
     * Encode space to + and any non alphanumeric character to %XX.
     * Taken from Apache Cocoon XSPUtil.
     *
     * @param text The string to encode.
     * @return The form encoded string.
     */
    public static String formEncode(String text) throws Exception
    {
        StringBuffer buffer = new StringBuffer();

        char[] c = text.toCharArray();
        for (int i = 0; i < c.length; i++)
        {
            if (isAlphaNumeric(c[i]))
            {
                buffer.append(c[i]);
            }
            else if (c[i] == ' ')
            {
                buffer.append('+');
            }
            else
            {
                buffer.append('%');
                String hex = Integer.toHexString((byte) c[i]).toUpperCase();

                if (hex.length() < 2)
                    buffer.append('0');

                buffer.append(hex);
            }
        }

        return buffer.toString();
    }

    /**
     * Decode space from + and %XX to its character from.
     * Taken from Apache Cocoon XSPUtil.
     *
     * @param text The string to decode.
     * @return The decoded string.
     */
    public static String formDecode(String s) throws Exception
    {
        StringBuffer sb = new StringBuffer();
        for(int i=0; i<s.length(); i++)
        {
            char c = s.charAt(i);
            switch (c)
            {
                case '+':
                    sb.append(' ');
                    break;
                case '%':
                    try
                    {
                        sb.append((char)Integer.parseInt(
                        s.substring(i+1,i+3),16));
                    }
                    catch (NumberFormatException e)
                    {
                        throw new IllegalArgumentException();
                    }
                    i += 2;
                    break;
                default:
                    sb.append(c);
                }
            }

            // Undo conversion to external encoding
            String result = sb.toString();
            byte[] inputBytes = result.getBytes("8859_1");
            return new String(inputBytes);
    }

    /**
     * Convenience function to check for alphanumeric characters.
     * Taken from Apache Cocoon XSPUtil.
     *
     * @param c The character to check.
     * @return true if it is [_A-Za-z0-9].
     */
    public static boolean isAlphaNumeric(char c)
    {
        return  c == '_' ||
               (c >= 'a' && c <= 'z') ||
               (c >= 'A' && c <= 'Z') ||
               (c >= '0' && c <= '9');
    }

    /**
     * Encodes any non alphanumeric character from a string to make
     * it usable as a form variable. Any non alphanumeric is deleted
     * from the string and the following character is uppercased.
     * A following second non alphanumerics is changed to a '_'.
     * A string starting with a numeric is prefixed with a '_'. <p>
     * Example <code>1abc.def*.ghI.JKL</code> gets converted to
     * <code>_1abcDef_GhI_JKL</code>.
     *
     * @param text String to encode.
     * @return Filtered string.
     */
    public static String encodeToName(String text)
    {
        StringBuffer buffer = new StringBuffer( text.length() );

        // ensure the string starts with and alpha character
        char c = text.charAt(0);
        if ( (c >= '0') && (c <= '9') )
            buffer.append('_');

        boolean makeUppercase = false;
        for (int i = 0; i < text.length(); ++i)
        {
            c = text.charAt(i);
            if (isAlphaNumeric(c))
            {
                if (makeUppercase)
                    buffer.append( text.substring(i, i+1).toUpperCase() );
                else
                    buffer.append(c);
                makeUppercase = (c < 'A') || (c > 'Z');
            }
            else
            {
                if (makeUppercase)
                    buffer.append('_');
                // else deleted
                makeUppercase = true;
            }
        }

        return buffer.toString();
    }

    /**
     * Convenience function to create an <code>java.lang.Vector</code>
     * within a template.
     *
     * @param size
     * @return An empty Vector.
     * @see java.lang.Vector
     */
    public static Vector newVector(int size)
    {
        return new Vector(size);
    }

    /**
     * Convenience function to create an <code>java.lang.Hashtable</code>
     * within a template.
     *
     * @param size The default hashsize (avoids the original default of 101).
     * @return An empty Hashtable.
     * @see java.lang.Hashtable
     */
    public static Hashtable newHashtable(int size)
    {
        return new Hashtable(size);
    }

    /**
     * Convenience function to create an array within a template.<br>
     * This can be used as a for-loop replacement:<code>
     * #foreach ($index in $formatter.newArray(10))
     *   ## do something N times or use $index
     * #end</code>
     *
     * @param size
     * @return An object array contining the numbers 0 till (size-1).
     */
    public static Object newArray(int size)
    {
        Object[] array = new Object[size];
        for (int i = 0; i < size; ++i)
        {
            array[i] = new Integer(i);
        }
    }

    /**
     * Convenience function to access an element of an array
     *
     * @param index
     * @param array
     * @return Element at the specified array index.
     */
    public static Object getElement(int index, Object[] array)
    {
        return array[index];
    }

    /**
     * Convenience function sort the elements of an array.
     * Needs JDK 1.2.
     *
     * @param array
     * @return The sorted array.
     */
    public static Object[] sort(Object[] array)
    {
        if ((array == null) || (array.length == 0))
          return array;

        Object[] sorted = new Object[array.length];
        System.arraycopy(array, 0, sorted, 0, array.length);
        Arrays.sort(sorted);

        return sorted;
    }

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:) Christoph