I have already posted two articles about how to solve the "ugly" URL problem. In the last article I discussed a solution based on a custom http module which does all the necessary checks and adjustments.

But one issue is still unsolved: Internet Explorer on Mac has an ugly bug then whenever the "action" property of a form tag is modified using Javascript a click to all items - even a label - will cause a postback to the server.

To solve this problem Microsoft has posted a fix for MCMS which will avoid this. But my code in the solution referenced above does exactly the same. So using this code in an environment will produce the error again. To avoid this problem it is necessary that the original action property of the template is modified on the server side rather than on the client side.

I looked through lots of documentation but did not find a solution for this dilemma which works in all situations - even if it is necessary to change the action property to point to a location in a different web application.

So finally I decided to implement an http stream filter to solve this problem. The stream filter needs to intercept the http response stream just before it is send to the client and has to modify the action property of the form tag. As this is not a very elegant solution I implemented the filter in a way hat it will only be active if the client requesting is a Mac client.

Below is the code for the relevant stream filter most of the code is only implementing mandatory methods and properties. The real work is done in the Write method:

public class FormTagFilter : Stream
{
    private Encoding enc = null;
    private bool closed;
    Stream BaseStream;

    public FormTagFilter(Stream baseStream, Encoding encoding)
    {
        BaseStream = baseStream;
        closed = false;
        enc = encoding;
    }

    public override void Write(byte[] buffer, int offset, int count) 
    {
        if(Closed) throw new ObjectDisposedException("FormTagFilter");
        string content = enc.GetString(buffer, offset, count);        // corrected Aug 27th, 2004
        byte[] newBuffer = enc.GetBytes(content);
        int pos = content.IndexOf("<form ");´
        while (pos >= 0)
        {
            pos = content.IndexOf("action=",pos);
            if (pos >= 0)´
            {
                pos += "action=\"".Length;
                int endpos = content.IndexOf("\"",pos);
                if (endpos > 0)
                {
                    string actionString = content.Substring(pos,endpos-pos);
                    if (actionString.IndexOf("NRMODE") > 0)
                    {
                        string head = content.Substring(0,pos);
                        string tail = content.Substring(endpos);
                        content = head+CmsHttpContext.Current.ChannelItem.UrlModePublished+tail;
                        newBuffer = enc.GetBytes(content);       // corrected Aug 27th, 2004
                        break;
                    }
                }
            }
            pos = content.IndexOf("<form",pos);
        }
        count = newBuffer.Length;                                    // corrected Aug 27th, 2004
        BaseStream.Write(newBuffer, 0, count);                  // corrected Aug 27th, 2004
    }

    public override bool CanRead
    { 
        get { return false; }
    }

    public override bool CanWrite 
    {
        get { return !closed; }
    }

    public override bool CanSeek 
    {
        get { return false; }
    }

    public override void Close() 
    {
        closed = true;
        BaseStream.Close();
    }

    protected bool Closed 
    {
        get { return closed; }
    }

    public override void Flush() 
    {
        BaseStream.Flush();
    }

    public override int Read(byte[] buffer, int offset, int count) 
    {
        throw new NotSupportedException();
    }

    public override long Length 
    {
        get { throw new NotSupportedException(); }
    }

    public override long Seek(long offset, SeekOrigin origin) 
    {
        throw new NotSupportedException();
    }

    public override void SetLength(long value) 
    {
        throw new NotSupportedException();
    }

    public override long Position 
    {
        get { throw new NotSupportedException(); }
        set { throw new NotSupportedException(); }
    }
}

To integrate this filter into the response stream I integrated the following code in the OnPreRequestHandlerExecute handler: