Why runat server required

If you want to disable a TextBox based on CheckBox value, you need to make a postback. Alternatively, you write a piece of JavaScript and deal with client IDs. You can also use expressions in value bindings. DotVVM controls can call methods in the viewmodel, which is testable. You can pass any arguments to the methods in the viewmodel, and async methods are also supported. NET Repeater control can be populated using data source controls or from a code-behind.

You can use HeaderTemplate and FooterTemplate to wrap the items in a custom element. The ItemTemplate element is optional, and you can specify the wrapper tag using WrapperTagName property. NET CheckBoxList control can return a collection of IDs, but the collection is not strongly-typed and working with selected items is not very straight-forward. Values which are checked will appear in the collection, and vice-versa. NET provides a wide range of validator controls that can display error messages.

The validation rules are defined in the page markup and the syntax is quite long. DotVVM takes advantage of. Now, that last point is key: a browser's renderer is an abstraction, allowing you to create in a few lines of markup something that would take hundreds or thousands of lines of low-level rendering and event-handling code.

And like all programming abstractions, it leaks a bit And each browser has developers working feverishly to plug the leaks in the abstractions. Except, for five years, IE did not. Other leaks were plugged, but the rendering engine became more and more sieve-like. And your event handler which you can even make private if there are no references to it from markup :. The first one creates a System. Button while the second one creates a System. Both are server controls, but the controls in the WebControls namespace generally has a bit more functionality than the controls in the HtmlControls namespace.

Typically they put some data in ViewState to keep track of their state, and they have server side postback events. Each controls in the HtmlControls namespace correspond exactly to an HTML element, while the controls in the WebControls namespace may be rendered differently depending on what the browser that is requesting the page can support. Validation on server side. Client Side Validation. RequiredFieldValidator Not working in Server side. Layout: fixed fluid. Web04 2. Strip HTML. Encode HTML.

Paste as-is. Code block. Quoted Text. Best guess. Optional Password. Richard Deeming. Corbin March Corbin March 25k 6 6 gold badges 71 71 silver badges bronze badges.

Do you happen to have a link to a site that has any of the "weird ads"? Yes I do remember the weird ads. Dave Swersky Dave Swersky If a control is running at the server, does that mean you can't select the elements using Javascript? Working with server-rendered elements can be tricky, however, especially with dynamic controls. NET tags. The OP knows what the tag means and what it does.

The question is asking in terms of language design - what makes the designer decides that even ASP. I don't have an answer, but the top answers addresses the question correct or not. Your answer does not, and that's the reason for my comment. ShaileshDev ShaileshDev 9 9 silver badges 16 16 bronze badges. Russ Bradberry Russ Bradberry Your answer is the very question reformulated.

My answer was simply stating that the runat attribute is there due to inheritance. My apologies for not being clear. A little too high in the stack, I'm afraid, my question was regarding why it was there in the first place. Thanks anyway — johnc. Again, not really answering the question, but I see what you are trying to say — johnc. Stefan Stefan 11 1 1 bronze badge. If JonSkeet is around anywhere, he will probably be able to provide a much better answer.

Carthi Carthi 4 4 silver badges 7 7 bronze badges. Elsewhere however it used to elevate normal tags to be used in the code-behind. Panos Roditakis Panos Roditakis 79 3 3 bronze badges. NET Web Forms Hope this helps clarify why runat is necessary Sign up or log in Sign up using Google.