Re: new design

[Colin Walters <walters redhat com>]

On Tue, 2005-03-15 at 15:23 +0100, Alexander Larsson wrote:

> I think we can use xml-rpc to update all the live items on the page. For
> instance, we can avoid massive polling by doing an async xmlrpc call
> from javascript that won't return until something changed. Then we can
> look at the result and refresh that part of the page. (Hopefully the
> outstanding connections won't be a bad problem for the server.)

I asked a friend who is a pretty expert web app programmer, he says this
is the way he'd do it too.  He did do a chat thing in JavaScript and PHP
and did a hidden iframe which polls every 5 seconds, but he says if he
did it over the blocking xmlrpc would be the way to go.  Just a sanity
check.

> For these async "poll" calls we need to keep in-memory waitqueues for
> various db objects that we need to trigger each time such an object
> changes.

Seems to me that we want some sort of signal mechanism; clients can then
subscribe to various signals.  A waitqueue per object seems bad since
then you have to poll the various queues.

> I'm not sure how much of the current codebase we will be able to keep.
> The Person class might be useful, and so does some parts of the
> Hibernate Setup. Maybe it makes more sense to start with a new cvs
> module, and lift over the things we want to keep using.

I agree with this.

> I'm gonna start experimenting a bit with getting some form live editing
> working in a web browser. Maybe this its a good way to start this whole
> redesign: pick one feature and try to get that working in a standalone
> web page. This way we can learn what works and what doesn't work, and
> what is needed before designing the more complicated server that does
> all these things at the same time.

Well, the live editing is clearly the hardest part.  The other features
we had a good start on in the previous yarrr web client.

> Some people have a gnome foot icon in the mockup. I assume that will be
> on people with cvs accounts. Is this type of markings different in each
> topic?

My assumption would be that it would be ☠ global.

> The mockup has a "Start a Discussion" button. Does this mean there can
> be several chats per page?

Yeah, I didn't understand that either; perhaps Seth's original thought
was that not all comments have discussions, and you had to explicitly
start one.  Or are discussions even strongly associated with comments at
all?  I thought they were because of the "> Discussion (Closed)"
underneath the top comment but now I'm not sure.