Svg Bug On Blazor With Rectangles

[musictopia2]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

When I have a drawing of a rectangle that when I have a function to select/unselect, then it gives a runtime error.
I have the sample also do circles and triangles. In those cases, no problem.
I even have 2 pages where one is selected to begin with and another one is unselected to begin with.
In those cases, its correct to begin with.
The issue is only with rectangles.

Expected Behavior

What I expect is to have the change done to the image that contains the rectangle instead of runtime error.

Steps To Reproduce

Go to this github repository that duplicates the problem everytime.
https://github.com/musictopia2/SvgRectangleBug

Click the 2 rectangle pages.
Then click on the image.
Everytime, the runtime error happens.

However, if you click the circles or the triangles, then it does what is expected.

Exceptions (if any)

Error: Cannot remove attribute from non-element child

.NET Version

6

Anything else?

No response

[mkArtakMSFT]

Thanks for contacting us.
The error usually indicates that the DOM has been altered outside of the Blazor context.
Do you happen to do something like that?

If not, we'll try to look into this at a later time as this doesn't seem to be a common issue.

Hi @musictopia2. We have added the "Needs: Author Feedback" label to this issue, which indicates that we have an open question for you before we can take further action. This issue will be closed automatically in 7 days if we do not hear back from you by then - please feel free to re-open it if you come back to this issue after that time.

[SteveSandersonMS]

@musictopia2 Could you provide a minimal repro that doesn't depend on external packages? It looks like the code that throws is in BasicBlazorLibrary or SvgHelper.Blazor, to which we don't have sources. If you could please show the minimal code that triggers the issue, without any external dependencies, we'll be able to take a look.

[musictopia2]

I did update the repository here
https://github.com/musictopia2/SvgRectangleBug
which now uses no external dependencies and the problem still occured.

[SteveSandersonMS]

I checked the code there and unfortunately it uses some known problematic patterns. In particular, this k++-type code - see https://docs.microsoft.com/en-us/aspnet/core/blazor/advanced-scenarios?view=aspnetcore-6.0#sequence-numbers-relate-to-code-line-numbers-and-not-execution-order.

If you are able to reduce this to a truly minimal example I'll certainly investigate. That means producing the smallest number of lines of code that triggers the problem. This definitely doesn't involve a whole general-purpose SVG rendering system, as it could be reduced to just the framework API calls that it would perform in this specific case. Otherwise there's a very strong chance that the product engineering team would just be debugging this custom SVG rendering system (which may well be where the bug is) rather than spending our resources on improving the product. Hope that makes sense and seems reasonable!

Hi @musictopia2. We have added the "Needs: Author Feedback" label to this issue, which indicates that we have an open question for you before we can take further action. This issue will be closed automatically in 7 days if we do not hear back from you by then - please feel free to re-open it if you come back to this issue after that time.

[musictopia2]

I was able to reduce to a minimal example without any custom rendering. Everything was hard coded in the BuildRenderTree code and the same thing happened.