What to do with RDS?

[calgarychinese]

Hi there

I got this application (big one, like 150 asp pages or so) that I'm maintaining now and that has been in production for a long time.

What worries me the most is the technology it uses. It uses client side RDS which Microsoft has since stopped supporting. So the application is fine as long as there are no major bugs or problems with it. But in the long run we know we need to do something about it.

If I don't want to do a major application rewrite, what would you suggest?

(In fact, even though the application was started a long time ago, recent new development, such as those done in the last 2 years was all done with server side processing, pure asp, pure xml, etc so those are fine. I'm talking about the other 80 pages that were written with the RDS <object> tag that I don't know what to do with.

Any suggestions?

1. Are there any similar technologies that Microsoft is still using, that is client-side processing, so I can simply replace one <Object> tag with another? That would be the quickest fix.

2. If not, what's the next best solution that would minimize the amount of time required?

3. If there isn't one to question 2 above, does it mean it'll be ultimately a complete application rewrite?

Thanks

 

[Sheco]

If you want it to be client-side then you can read up on the technique called "AJAX" but that would still be a complete re-write.

If you've got a re-write either way then I'd go with an all server-side approach.

 

[calgarychinese]

Hi Sheco

Is AJAX endorsed by Microsoft? Or is it actually an MS technology?

Thanks

(your reply is very unwelcomed...... haha... sigh.... but I guess sometimes it's the way it is....)

 

[Sheco]

AJAX = Asynchronous JavaScript And XML

Basically you use an instance of the xmlhttp object in client-side script.

This object has the ability to make its own HTTP Requests and receive the corresponding HTTP Response.

Microsoft first created this object as a way to use ActiveX to fetch additional data from the server in xml format... that was back when XML was the new buzz word... xml was going to cause world peace and all that.

Anyway, it wasn't long before people realized that you weren't just limited to xml... they started using it more like a remote procedure call... to go get some more or different data from the server without a page transition that is normally done when you submit a form or click a link. A good example of this is maps.google.com where you can drag and scroll the map... and then keep dragging over and over and the map will show without a page transition... its not like the program downloads the entire map to everyone... that would be too much of a bandwidth hog... the client-side script detechs when you have dragged off the map and then requests new map from the server.


Anyway, now the other browsers have their own version of the xmlhttp object so it isnt just a microsoft only thing anymore. Actually a lot of anti-microsoft people have jumped on the AJAX bandwagon because they belive they will be able to make a web application that works exactly like MS Office using this technology. That would tickle the microsoft haters to no end!

 

[dilettante]

Perhaps you could pass your query parameters to something server-side (ASP, etc.) via XMLHTTPRequest POSTs. The server-side logic would perform the query and return the result as an ADO Recordset persisted as XML. The calling page could populate an unconnected Recordset client-side and use the data from there.

Updates could be handled similarly.

The server side logic could do some fairly robust data integrity and security checks. This avoids the dangers of RDS exploits and SQL injection issues, and leaves your client-side logic largely intact.

Of course this is basically "AJAX" (a.k.a. Remote Scripting) anyway.