On Thursday, February 9, 2017 at 1:07:27 AM UTC+9, OvermindDL1 wrote: > > It is not strictly be design (that might be a bug if you can come up with > a simple descriptive example that we can copy into elm-try or so), but it > is easy to work-around. >
Did you try my gist? I updated it to make it easier to work with elm-try. https://gist.github.com/Shump/bd778bde23af0dd3f8c95f92ec45fc33 If you run each of them and enable "Paint Flashing" in chrome's devtools (open console -> click "three dots" option menu -> click "Rendering" -> check "Paint Flashing"), you'll see that the version with *use* tags repaints the whole board (bad performance), and the one using "normal" shapes only repaints the hovering tile (good performance). > What I do is make just an integer (some primitive value), and just > increment it whenever the view should be updated (gotta be careful to catch > all cases though), then use that as the key in a `lazy` call that then > wraps the rest of the view, that way the view only updates when the integer > key is incremented (I wrap it around at 2 billion just-in-case that ever is > hit). > > However that makes the diff compare only the key before checking > everything else, and if the key integer is unchanged then the entire view > is skipped for diffing, thus making it very fast. :-) > > You can add more keys and more lazy's for sections of the board as well if > you need to get more fine grained. Just always try to use a primitive as > the key or a record that is passed verbatim from model update to model > update. > I feel like it shouldn't be necessary to look into adding keys for performant rendering with *use* tags when it is not needed for "normal" shapes... This is why I'm wondering if this might be a bug... or if it turns out that this is intentional, and *use* tags are performance killers, it should probably be mentioned in the documentation... I'm sorry if this wasn't clear in my original post... I hope this makes things clearer. -- You received this message because you are subscribed to the Google Groups "Elm Discuss" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
