Introducing MarkdownSharp � Blog – Stack Exchange:

Jeff Atwood author Dec 27 2009

> Why don’t you just use an Ajax call for the preview, Jeff?

We tried that on http://careers.stackoverflow.com in the CV entry fields which support Markdown, and people hated it. I can’t blame them. The 200 ms latency (and that’s the best case) to get the preview to update is kind of a bummer.

But I agree in principle that keeping two sets of code in sync, in two different languages, on two totally different platforms, is a huuuuge PITA.

Look, in a perfect world, yes, you should always have everything related to data qa for a page on your server. In this case, that something isn't just validation, which obviously must always be on the server (but soooo often isn't), but also Markdown formatting. You're going to have this stuff on the server, so why not kill two birds and tie that logic into the client?

But that 200ms really is important enough to ensure that, after you know your server-side logic is ready to go, you have that PITA version ready for your client as well. I hate two languages on two platforms, which is part of why I think Node.js is fairly popular, but the bottom line is that users do expect quality, quick interactions which can only be done with [only marginally] thicker clients.

Labels: coding, javascript, style, validation