dev|sushi

Recently at work I needed to allow for the download of sensitive files over the web. Right away your mind should jump to the security issues involved with such an undertaking. How do you allow for download without compromising the sensitive data? There is a simple but flexible method that will work perfectly.

I’ve had several people ask about redrawing a page that contains Dynamic Controls. The idea is that you have a page with a “Save” button that posts back but the page reloads exactly as it was. You can think of it like the “Apply” button in Windows but on a web page. The heart of the issue is what is the proper way to redisplay the data in the dynamic controls since they don’t have a viewstate.

I have received a few requests via email and in comments for more detail on how to get your data back after postback with dynamic controls. This evening I started to put together some code examples and mulled over the details of the article in my head. The first step was to re-read my previous two articles so I could get my bearings on where to start. Part 1 of this series is an initial outline of how to create dynamic controls and use Request.Form to collect the data after postback. Part 2 went into detail on how to figure out which button was clicked to cause postback using a JavaScript technique. In the middle of re-reading the second article I had an epiphany. There is a better way to do that! The proper method is standards compliant, accessible and is outlined in the W3C HTML specifications. So I will put the original article on hold and explain this technique.