Removing the leaky abstractions from WebForms
My preferred approach to develop on the web is using MonoRail, but since I am doing a lot of work for clients, they sometimes get to choose the technology. My current project is using Web Forms and Atlas. I already mentioned that I am using Igloo to provide a truer MVC support for WebForms, it is not as good as what MonoRail can provide, but it is nice. (The only problem is that I keep feeling that my controllers are getting too big and complex, I have finally finished doing a stint on the UI that left me little time for refactoring, but it is getting past time to do it).
I believe that I have already mentioned in the past that I am not particulary fond of Web Forms, it is a leaky abstraction, trying to bring a semblence of statefulness to something that is stateless by nature. I did some big projects with WebForms, and I was bitten really bad by some of the stuff that went under the hood.
At any rate, here is the stuff that we came up with for the project:
- Disable viewstate. That means that I disable it at the web.config level, and never enable it. Like most ASP.Net developers, I have been fighting with ViewState for a long time. It means that controls "forget" their state, and that sometimes I need to maintain state on my own, but it means that I get a lot more control on what is going on in the application. For some annoying reason, I still get a _VIEWSTATE variable in the pages, I assume that it is the ControlState, but so far I haven't dug far enough to find yet. I got some worrying responses from team mates, about what the implications of this can be. I had to sit and show them with Fiddler what is going on the wire to make sure that they understand what is happening.
- Understand how Update Panels work. They are really cool technology. I am usually critical of Microsoft, but I have to say that I like UpdatePanels, they are a good solution for a problem that most WebForms developers need to deal with.
- Do not get the data from the controls, get it from the request. There are two reasons for this, the first reason for it is simple, it is possible to access the request object from everywhere, it is much harder (and not wise) to pass the controls references. The second reason is that the controls will lie to you about their state. I just run into a situation where a DropDown reported SelectedValue = "" when the selected item was the one defined on the aspx (with append data bound items set to true), while on the request it was "0", the value given in the aspx.
- Do no processing the the code behind files. When my controllers do not get the data directly from the request object, they expose methods such as:
public ICollection<Policy> GetPoliciesForCustomer(string maybeId);
- Don't bother with the designer.
- Consider using the AjaxToolkit where appropriate, but be aware that it is not mature yet. If it gives you the least bit of trouble, drop it and go to Google.
- Watin is really cool.
- Would you write the tests already?
It is not comprehensive list by any mean, but this is just a few things that were brought up.