Please don't take away classic rendering!

[davidstone]

The new rendering approach has been a bad experience for me from the start, and hasn't improved.

This is largely because my app is a little complex and makes a lot of use of auto-height, with elements within a gallery which size and resize according to the contents as some are hidden or shown.

I'm also seeing different behaviours across different browsers, and mobile. For example in Chrome my autoheight labels don't expand, they just show about 5 pixels worth of height - the tops of letters. The same is true when running the PowerApp on my phone using the client app, yet using Edge it renders as expected.

As well as the display issues there are also massive performance issues. Again, this might be due to the particulars of my apps - I know that simpler apps I've developed work better in the new rendering engine. But the app I'm worried about is slow in the new engine - any click that results in a UI change, and even scrolling, feels like wading through thick mud.

Conversely the classic engine runs the same app perfectly smoothly.

What are the timescales for removal of the classic engine?

[Anonymous]

@_Corey_  I am still having issues with this - in studio my app essentially disappears and stops working, in web player it is fine but with improved app rendering turned on I can't even edit the application; 

I suspect this is because I have a gallery within a datacard that I am collecting results from - this is the best and most efficient way that I have found to deal with the app without having hundreds of controls. Do you know if there is a fix for this coming?  This app is already in production so I will need to redesign the app before the release if this isn't fixed. 

Thanks 

[_Corey_]

@Anonymous Does the Gallery control have an inner/nested Gallery?  The next time you encounter this issue, can you please capture a session ID and paste it to this thread.  You can get a session ID from File -> Account -> Diagnostics -> Session details.

[Anonymous]

@_Corey_  Thanks for the quick response, much appreciated.

No nested gallery, I have a lot going on in the gallery to make things visible or not within the gallery and its quite a large gallery with 170ish rows of questions each with a radio control from which I collect the selected results from.  

Sure the session ID is Session ID: abb9f134-02b4-4dd7-a772-cab52c30d7d1

PowerApps 3.19091.18

I also tried exporting the app, and importing again, and I tried saving and editing the app with both delayed load switched on and off, but got the same results. 

[Anonymous]

Just to add to this thread - I have taken away all of my galleries that sit within a datacard (and placed them in a screen without a datacard) - and I am still getting this issue. The app renders okay with enhanced enabling switched on (when in editing/studio mode) but when I scroll through the gallery then the screen goes blank as shown in screenshot, then all other screens in the app do the same and go blank. 

I exported the app and re-imported as new, but still no luck. The gallery I am using is using a collection as a source, that is fed from sharepoint; here is a list of all the functionalities that my gallery is using; 

Property

Items: Filter(Collection,Category<> "CategoryID")

Controls within gallery 

Label = thisitem.CategoryRef 

Radio = If(ThisItem.CategoryID = "N/A",["Yes","No","N/A"],["Yes","No"]) 

Gallery Separator

Label = If(ThisItem.Ref = "Header", "", ThisItem.Question)

Label = ThisItem.Ref

Label = If(ThisItem.Ref = "Header", ThisItem.Question,"")

I am going to try and copy the app by building it from scratch in a new app becuase this wasn't happening up until recently, other than that I am at a loss at what to do with this aside from not using a gallery. 

Thanks 

[Anonymous]

okay so, rebuilt the app and that didnt work either so I do not know what everyone else is doing, but whatever I am doing it is making it impossible to edit my app. 

Session ID: 6f4284bb-677e-4423-9ffd-7e2aba8e756e

[_Corey_]

@Anonymous I can see from telemetry that your app is triggering an stack overflow error.  This is likely causing the internal state of the app to go awry and may explain why the UI disappears.  I will report this error to the appropriate team interally to address it. 

In the meantime, you may be able to reduce the overall call stack size by taking a few measures:

1. If you can, reference the data source directly in the Gallery.Items formula.
2. In Gallery.OnSelect, set a variable with the selected item: Set(galSelected, Gallery.Selected).  Then, instead of forms (or any other controls) referencing Gallery.Selected, reference galSelected instead.  This will ensure that controls that are presently listening to Gallery.Selected are not presented with new data when Gallery.Items changes due to the Filter() criteria.

[Anonymous]

@_Corey_  This is brilliant, thanks for this, much appreicated.  I was able to identify the gallery and found another way around it.

The offending gallery was filtering a collection on the items property with this "Filter(collection, Not(IsBlank(column)))", when I removed this it stopped the issue completely. I then carried on building my app, and the issue reoccured, but it was a similar issue with the gallery so for now I have stepped away from the gallery to move forward for this partiuclar peice of work. 

I did this becuase I was trying to get a table of actions to populate in a htmltext field for a submission email, if there were no actions then I didn't want the table to appear in the html body. Instead of using the gallery.allitems I used ForAll(collection) in the htmltext field which actually seems a better way to do it. (there are posts on how to do this but if anyone wants to know and can't find those them happy for you to message me). 

Again, thanks for the help Corey, much appreicated. 

Best