[Seaside] push-model of interactive web pages

Lukas Renggli renggli at gmail.com
Wed Apr 12 14:25:56 UTC 2006

I redid the JavaScript part, so that it is using XMLHttpRequest and
not the ugly hidden iframe technique. It is now working in Safari and
FireFox. Someone with an Internet Explorer could probably get it
running there too.

> I like the approach of using XMLHttpRequest but having it complete
> after a period of time. So have the request go for 1 minute and after
> that the connection is closed and the browser fires off another
> XMLHttpRequest. This works around proxies that have short timeouts and
> close iframe connections after a certain period of time.

The problem when disconnecting is that the application might loose
events, however my first try and the one I published just now are both
reconnecting in case the connection is lost. Could somebody with a
proxy confirm that it works?

> The downside of both approaches though is the fact that some browsers
> limit the number of open connections. I believe this is mandated in
> the HTTP/1.1 specification? This means that if you have a long lived
> 'comet' connection then it may affect other xmlhttprequests going on
> if you go past that connection limit. I don't know if this is actually
> a problem in 'real world' apps though.

Yes, I observed that FireFox only allows one long-lived connection,
but I guess it blocks the other windows because they request the same
URL, and this could be easily fixed. Safari doesn't care, I can open 5
windows with the same comet connection at once.

Now the next steps will be to find a better model for Seaside, but
maybe after Smalltalk Solutions ...


Lukas Renggli

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