Does adding server side code in markup page (aspx) affect performance?

Question

At my previous job, our team architect was strongly against including any server side code in the markup, even simple ID's, so this code would not be allowed to get checked in:

<script>
    var el = document.getElementByID('<% SomeElement.ClientID %>')
</script>

instead you had to inject it into javascript via Page.ClientScript.Register...

His reason was that asp.net has to recompile a page every time if it has those server code includes.

That didn't sound right for me but I couldn't find any proof of either.

Any ideas? Does that change performance or not? I know that server side code in markup is not good because of difficulties in debugging and readability and the whole idea of separatin gcode form markup, but I am only interested in performance differences.

Thanks!

Answer 1

Your architect is wrong.

ASP.NET compiles a page once, regardless of whether or not it contains any C# code. It will recompile the page only if it detects that the ASPX file was changed since last compilation.