New Analysis Engine

[GregLi]

Similar to the dependencies between cells in a spreadsheet that drives recalc, Canvas apps depend on understanding all the dependencies between properties of controls so that data can flow between them properly and efficiently.  We call this process "dependency analysis" and it is something that Studio is doing all the time in the background while you are editing an app.

For more than a year, we have been rewriting the analysis engine to both perform better and to optimize the results.  The result is that complex Canvas apps that can take minutes to load should load significantly faster.  It is a major change, at the very heart of Canvas apps, that we have been working on for over a year.

We are very excited to announce that this feature is now available as an experimental feature for your testing and feedback.  Please make a copy of complex apps, turn on this setting, see if you run into any problems in Studio and at runtime, and provide feedback here in the forum.   

Do not use this feature in production!  There could be subtle behavior differences that will take time to discover, just because the app loads and saves doesn't necessarily mean all is well, some testing is needed too.

Thank you!  And with your help we hope to turn this feature on for everyone soon.

[Commander_Data]

Unfortunately I cannot. I will try a clean blank App and see if it still complains at the defaults variable. I maybe able to send that. Company restrictions mean I would not be able to share the full App.

Thanks for the reply.

[Commander_Data]

Further testing seems to indicate it's a timing issue in the New Engine. It' complains of an Office365Users.UserProfileV2 parameter error, but this seems to go away.

It seems to try and access the global variable 'defaults' created in the OnVisible property of the Splash screen, in App.Formula, before it's set (or defined). So if I edit the App.Formula, remove one semi-colon, and add it back in, all the errors go away and the design studio previews without issues (seems a little slower).

A test by a colleague in play mode of the published version (in Dev), was showing his Department (read from the Office365Users, was seemingly changing and the 'active' dots a the top of the screen were constant. This seems to indicate it was still trying to read, and reread, the users details.

This action is different from the old engine. If there is anything else I can provide, except the ful App, please let me know.

[bspang]

We noticed that with the new analysis engine, we lost the ability to reference labels as variables as easily as we used to. For example, if we wanted to show some control if a checkbox was marked true, we used to be able to write this in the Visible property: If(Checkbox1, true, false).

With the new analysis engine, we now have to write: If(Checkbox1.Value = true, true, false). 

We have noticed the same behavior when doing calculations. For example Label1 + Label2 now has to be Value(Label1.Text) + Value(Label2.Text). 

[d2034]

Hi, I have an issue with a published app, and the "New Analysis Engine" could be the cause.  I wanted to use UDF, and this feature requires the new engine.  In the Studio, everything is fine.  Once I publish the app, the height of some custom component controls is changed.  I originally posted the issue here.

Example:  My container "conLayout" is set with Height 40, Max-Height 40 and Flexible height is false.

In the Studio, I see the container correctly.  Once published, the height is not 40, and, looking at the html source, I see the style property of the div is set to 200px.

I tried many things to regain control on the height but nothing successful.  I did not found a pattern to reproduce the issue (still investigating).

Now I am a little stuck with this issue because I used UDF at many places as formula shortcuts, and disabling UDF and the new engine will cause a ton of errors.  😕

EDIT: It's confirmed, this size change is caused by the new engine.  Here is screenshots that show the effect I am talking about.  The only difference between them is the "New Engine" being enabled.

[ShantanuP]

@d2034 , Is there a way for you to send a repro app (msapp) for us to further investigate the issue? This would be helpful. You can send msapp in a private message. Thanks!

[d2034]

Hi, thank you for looking at this.  Here is the .msapp file.  I wasn't able to send you a file in a private message.  

• After loading this .msapp file, activate or deactivate the "New Analysis Engine" feature, and publish the app.
• Run the app.
• Click on the "Goto Header" button.

When the new engine is enabled, you will notice 2 things:

1. The left side "badge" is cut, it's not shown entirely.  In the studio, the size of this badge is 22h x 90w.  In Play mode, it's shown as 32h x 32w.
2. On the right side, the X button is set to 40h x 40w.  In Play mode, it's shown as 40h x 160w.

When the new engine is disabled, both controls are shown with the right size.

I hope you have all information you need, feel free to contact if you need help 🙂

[ShantanuP]

Thank you for sharing the msapp file. We are investigating it.

[claytsch]

After enabling the "New Analysis Engine", I had quite a few errors seemed to be related to setting/patching variables using slightly different schema.  After cleaning that up, it does seem much smoother now.  The only other issue I seem to have now is with component inputs.  Before enabling the "New Analysis Engine", I was able to pass inputs with dynamic schema/columns.  I could reference "Self.Items" and reference any Column that was passed to the "Items" input property.

Now, I can only reference columns that are specifically defined inside that Component Property.  I'm sure I can come up with workarounds for most cases (example below) but the formulas are much clunkier and less efficient now and I'd have to do this for dozens of instances.

BEFORE

Items:
Sort(
AddColumns(
Filter(
'Workspace Types',
Rank
),
"Id",
Text(ID),
"DisplayName",
'Name (Title)'
),Rank
)

Defaults:
Filter(
Self.Items,
Value(Rank) < 10
)​

AFTER

Sort(
AddColumns(
Filter(
'Workspace Types',
Rank
),
"Id",
Text(ID),
"DisplayName",
'Name (Title)'
),Rank
)

Defaults:
Filter(
Self.Items,
Id in Filter(
'Workspace Types',
Value(Rank) < 10
).ID
)

[claytsch]

Maybe this is an intended change to reduce the amount of data being processed.  I wouldn't mind updating my components to be more efficient but the issue I have is that when you update component property "Defaults", it reset's all of the values for each component instances to the new "Default".

I have to copy every instance property value to an external document before I update the property in the component and paste it back after the update.

It would be so much more efficient if the existing values stayed the same and would just show an error if the existing values aren't compatible with the new property schema.

[PeterCBell_au]

You know that for this issue and many others it usually ends up you guys requesting we send you a copy of the app. There are far too many instances of developers not being able to work out what is going wrong, not because they lack intelligence, but because there is far too much "black box" stuff going on (eg. the "analysis engine")

Does powerapps have a switch that tech support uses to send debug output with varying levels of verbosity to a window (similar to windows dbgview). That is, if the editor or a published app is started with that switch on, the editor, playing in the editor, and interaction in published apps sends information about what is happening under the covers to a window within the monitor?  

This is especially important because of the on demand UDF and formula recalculations and parallel processing taking place- when an action is invoked it is a mystery as to what chain of calculations are actually taking place.

If so, it would surely be worth sharing or implementing!!

(as as a bonus allow the developer to Log("message") to the same debug window). 

I for one would gladly put up with some loss of speed with debug mode on when trying to sort out an issue.

For example, I have an app that breaks the editor randomly without the "analysis engine" on, and was advised by tech support (after some weeks and sending in the app) to turn on that mysterious feature to resolve the issues- which it did BUT this is a feature that shouldnt be used in published apps.