Lottery Student Reg is slow with lots of classes per timeblock

[aseering]

It seems that ExtJS creates large numbers of DOM objects (mostly

's) around items that it creates, particularly formsets. With a large program, this can be so dramatic that the page-render time is slowed substantially just by the browser trying to figure out what the layout of the page should be, with these huge piles of objects.

I'm not sure what the right solution to this is. Doesn't ExtJS have a grid control of some sort?; maybe that control uses a simpler layout mechanism? Since all we want is basically a giant table.

[gkanwar]

Two things come to mind:

1. We're not using the most recent version of ExtJS, perhaps that might make a difference?
2. From what I heard, ExtJS does not support multiple browsers very well. Perhaps we should consider moving away from it? This may be too radical of a change at this point, I'm not sure how much effort we want to put into this?

[aseering]

Hm... It could be worth trying an upgrade, to see if it works.

As for moving to something not-ExtJS, I feel like there are probably more-pressing things to do right now; but if Stanford also moves to a lottery, they being the next-biggest program after MIT and probably big enough to be hurt by this as well, I think we'll have to come up with something... This code is pretty ExtJS-integrated; I don't think it would take too long for someone to port who knows this code, ExtJS, and the target framework pretty well, and assuming the target framework supports the sorts of widgets that this thing wants (most notably the tab panel). But it'd be some amount of work even then, and it'd probably be a bunch of work for anyone who didn't have all three points.

[aseering]

This got improved somewhat in c7050bb, and substantially in eebfa01. I now consider it to be acceptable for most users; though the page layout I'm using is still fundamentally a hack (a bunch of one-row tables in a row rather than one big table). Should probably get polished more; but I think the basic issue is sufficiently resolved for now.