should every element with runat=server have an id attribute?

Question

I have inherited an asp.net website to maintain

when looking at the aspx page, almost every element with runat=server don't have id attribute defined.

should I go through every element and add one?

Answer 1

Unless the control is inside a repeating control it should have a unique ID attribute assigned to it. Here is some MSDN documentation on how to add server controls to an ASPX page.

Answer 2

You only need to give them ids if you're going to reference them in your code. If you're not referencing them at all you might wonder why they are .net controls and not just html elements.

Answer 3

ASP will assign an unique ID if you don't. Sometimes I don't bother when I won't be manipulating it.

Answer 4

Speaking specifically to your situation of having inherited an app, it's not a pressing issue. ASP.NET will automatically generate IDs for them at runtime.

Generally, aiming to replace those controls with HTML elements (as someone else mentioned) is a good idea. Do be careful though. Just because an element doesn't have an ID doesn't mean it's not being referenced on the server side at runtime.

Answer 5

You don't need to set IDs to the controls you don't reference. ASP.NET will do it for you. That's it.

This does NOT automatically mean, they can be replaced with HTML controls. Having a control with runat="server" without having an ID set is perfectly reasonable. e.g.:

<asp:ListView runat="server" DataSourceID="someDataSource">