Design help!

Hi All

I am a familiar with desktop development (VB6/ .net), and would appreciate some help getting into web development.

Basically I am designing a web application in ASP.NET that shows the status of some components in our system.

Simple HTML output is fine to display the status, but as http is essentially connectionless, I am having a problem getting the client to update when the web app is notified of a state change.

I have tried a few things, namely
1. Automatically refreshing the page every now and then.
2. Using a frames and having a hidden page to request the data, check if it has changed, then trigger a page refresh etc.

These are bad solutions at best.

I am thinking that I need to explore the ActiveX / Java applet route.

What are my options? Is ActiveX on its way out? Is a java applet compatible with asp.net?

Is there some way of having a 'connected' page in asp.net, or way of having an object on the client that is connected to the web app?

Any help is appreciated,
Thanks!

Hi,

Just some suggestions for ya that may help you out learning how to design web applications.

1. Learn HTML. Understand HTML by itself, without the added functionality that ASP/JSP/PHP/ColdFusion/etc adds to it. Remember that the end result of all of these scripting languages is that they create HTML for a browser on the client side (don't believe me? do a View Source on any ASP page... all you see is HTML) Browsers don't understand ASP or JSP or PHP - they understand HTML. The scripting languages just make it easy to create dynamic HTML, do server-side processing, and talk to databases.

Most long-time programmers make the mistake of thinking that there's "nothing to" HTML. They're wrong - there's alot to know and understand...

Here is a great reference an tutorial for you:

http://www.estek.net/estek/idocs/


2. Web applications are not desktop applications. Use HTML to do what it was designed for, don't try to make HTML become a desktop application. HTML is not meant to be connected to a database, HTML is not meant to display real-time information. You need to change the way you look at the world when you design real web applications.

To (hopefully) answer some of your questions directly, people expect web sites to act like web sites. Look at Yahoo - when I get stock quotes, I expect to hit "refresh" to see the latest quote. I don't need them flashing across my screen in real time - when I want an updated quote, I click "refresh" or the appropriate link and I get the info. Look at how existing "good" websites (like Yahoo) implement similar functionality to yours - this is the route you should take if you want to create a web app.

As for ActiveX and applets - yes, you can use them, but then you're really just developing a desktop app that lives in a browser. That's not really a web app, and it starts to limit your audience. Many people don't want ActiveX apps installed in their browser (for security reasons) and while applets can give you neat functionality, they're fat, complex, and take a long time to load. Bad mojo.

If the goal is to create a flexible web application freely accessable by any browser, focus on designing a web app, not an applet or ActiveX component. Focus on designing your app to work like a website and not a desktop app. It's a big change in thinking!

If you absolutely need real-time data connection and refresh, then you're not really creating a web app. Swing (applets) are probably your best bet in this case if deployment over the Internet is a requirement.

Hope I was helpful!