Gallery scrolling performance issues

[pmcgurn01]

I'm hoping there's some kind of planned performance improvement work on the gallery control, but posting this, in case there isn't.

At present, the gallery control is incredibly clunky/laggy when scrolling any faster than what I'd consider to be "unreasonablly slow".  The behavior is 

1. I scroll
2. The rows move up
3. There is a huge empty whitespace for about 1-2 seconds
4. The white space fills up as the elements render
5. Repeat process

I will note:

• It doesn't matter if I bind the gallery to a local collection or directly to the data source.   Since my data source (Azure SQL) is too large to be cached to a collection, I'm limited to direct binding anyways.
• It's reproducible in web player (Chrome browser) and mobile (iPad app)
• I am using ThisItem to bind all data to controls in the gallery.  At this point, I have 8 controls total in the template row, which are a mix of images (2 icons) and labels (6 of those).
• It seems to be completely unrelated to latency in the network.  I can verify this by watching the troubleshooting console, and the lag isn't tied to any network calls, though I do see those happen at each 100 rows of data or so.
• I can reproduce this on other data sources that I am caching to a local collection on app OnStart, where I see this empty whitespace when I scroll fast enough to where the gallery would need to render more than ~5 rows at a time.  In that case, the datasource is cached to a local collection, and that gallery only has 5 labels in the template row.

I'm attaching a video of this behavior.  While the lag you see might be "acceptable", it's not a great user experience on any platform. I understand that the gallery is probably working as designed for keeping resource utilization low on mobile devices, however, since this can be reproduce on mobile, too, I'm asking that Microsoft improve this. 

[cwebb365]

That's what I do, have a bulk edit button with the pop up window and a single double click that pulls out form on the right to do single / full edit to records. 

For bulk I basically get all the selected items into a collection. Use updateif's on that collection with the collection vs. what's in the control in the popup, then patch the collection back. In this case Tickets is the table.

//get selected items to collection.  

ClearCollect(colItemsSelected,ForAll(grid_Tickets.SelectedItems As Sel,LookUp(Tickets,id = Sel.id)));

//updateif for each column i want them to be able to bulk edit

UpdateIf(
colItemsSelected,
StatusID <> cmb_BulkStatus.Selected.id,
{StatusID: cmb_BulkStatus.Selected.id,ModifiedBy:varUserID,Modified:Now()}
);

//Then patch collection back

Patch(
Tickets,
colItemsSelected
);

Seems to be most performant. 

[cwebb365]

Looking back at it now, the ForAll is probably the slow way of collecting the selected id's, but at the time I dont' think it was delegable to use in, still isn't on drop downs I think, Dataverse has preview membership 'In' support now, so might be able to make it quicker there, but anyway, you get the idea. 

[cwebb365]

Well @WheresWally have you tried the Modern Tabel control lately? I just played with it again and looks like they finally updated it again and it's actually somewhat usable and close to my control. It doesn't have a select all thou, but it has multiselect and you can access the selected data and onselects now that seemed missing with a little bit of branding as well. Tested sorting and seems to work well, but you have to use a default dataset, once you mess with it with functions seems sorting breaks, might be the reason sorting doesn't work on mine, might be something with that and the datasource delegating it somehow. 

Anyway, just thought you and others should know about that control is getting close to being actually usable and performance is there as it's same fluentUI controls. Turn on modern controls in app settings if you haven't and you'll see the table control. 

[WheresWally]

Hi cwebb, 

Thanks for your update. I had accepted the scrolling lag in my existing grid and was going to use it, until I realised that filtering and letting in a subset of rows around the 800 mark would load for at least 16 seconds each time you changed a filter. 

I'm now rushing to implement the modern table as my un-editable grid with a single row edit container and a batch edit container. Single edit is working okay but I can't for the life of me get anything to understand which things are in the multi-selection. 

Select all seems to be do0able via ctrl+A which would be okay if I could check in on what's selected (ID in Grid.SelectedItems.ID for exampled). 

Have you got any ideas on that? 

Thanks again

[WheresWally]

I should add that filtering in the modern grid is still not implemented (though they have a greyed out button for it..grrr) But I've used my original filter comboboxes with some success. Though I have noticed that sometimes a second applied filter just doesn't take effect. Will be looking into that...

[cwebb365]

That's why the grid I uploaded is better, it supports all those things. I just tried and same thing for me, on the modern table it only returns a single record regardless of that select all which is crap.