Sp-dev-docs: onRenderCell() not called for all items in a large list when users scrolls whilst field customizer is being initialized

[orbus-jmyron]

Category

• [ ] Question
• [ ] Typo
• [x] Bug
• [ ] Additional article idea

Expected or Desired Behavior

onRenderCell() is called for each cell even if the user starts scrolling through the document list before the field customizer is full initialized.

Observed Behavior

onRenderCell() is not called for some of rows that are in the process of being loaded due to the user scrolling the document list.

Steps to Reproduce

• Create a Field Customizer by following these instructions.
• Create a list with 200 or more items (can be a document or item list).
• Debug the field customizer as per the instructions in the article.
• Keep scrolling down the list until the field customizer starts modifying the field.
• Scroll back up the document list. Note that some of the documents have not been customized.

This reproduces easily on Chrome and less frequently on Firefox on both Windows and OSX.

Video demonstrating the above.

[msft-github-bot]

Thank you for reporting this issue. We will be triaging your incoming issue as soon as possible.

[StevenDeRoover]

I have noticed the same issue

Edit: possible workaround (which I have not tested intensively) could be to use a window.setTimeout (0ms, 20ms, ...) in the onRenderCell function, to render your stuff deferred.
Edit2: this does not always solve this issue, although it does not occur that often

[orbus-jmyron]

Thanks for the potential work-around @StevenDeRoover.

It doesn't seem too make much of a difference for large document lists. Still seeing exactly the same broken behaviour with the work-around.

It does indeed seem to work most of the time for items list though.

[cytron201]

@andrewconnell Hi. This issue is affecting enhancements we've built in SharePoint and deployed to our customers. Is there any timeline for when it might be at least triaged? I've tried contacting Gold Partner support for this but have been told by the SharePoint support team that it's out of their scope to assist with. Are there other means by which we can escalate it? Thanks

[StevenDeRoover]

Bump: one of my colleagues (for which we created a field customizer) reported this issue again. Appearantly it is still an open issue. Is there an update on the status of this issue?

[kemesfun]

@orbus-jmyron I have added 100 items to a list with fieldcustomizers and so far I am not having this issue. I will see what happens after I add 100 more. Does this issue still repro?

[orbus-jmyron]

Hi @kemesfun,

We've not recently been doing any development around this area, so will need to set things up again to try out. I'll get back to you in a few days.

[msft-github-bot]

This issue has been automatically marked as stale because it has marked as requiring author feedback but has not had any activity for 7 days. It will be closed if no further activity occurs within the next 7 days of this comment. Please see our wiki for more information: Issue List Labels: Needs Author Feedback & Issue List: No response from the original issue author

[orbus-jmyron]

Ok. So just dusted off the old sample project I had from when this was initially reported, and yes, this still reproduces.

Behaviour is actually slightly worse now, as it doesn't require the user to even scroll for the renderCell() calls to go missing.

The sample I'm using is still on 1.9.1 of the SPFX libs. Will try updating to latest version to see if anything changes.

[orbus-jmyron]

Just to confirm, issue still reproduces after the sample project is updated to 1.10.0.

[kemesfun]

@orbus-jmyron I created a list with 200+ items and still don't get this issue. I am not sure what is causing this issue at this point. Can you provide any more details on this repro?

[msft-github-bot]

This issue has been automatically marked as stale because it has marked as requiring author feedback but has not had any activity for 7 days. It will be closed if no further activity occurs within the next 7 days of this comment. Please see our wiki for more information: Issue List Labels: Needs Author Feedback & Issue List: No response from the original issue author

[orbus-jmyron]

Can confirm this no longer seems to reproduce with the sample library I've been using.

Just eyeballing it, there definitely seems to be a change in how scrolling behaves and items renders since I last looked at this.

[msft-github-bot]

Issues that have been closed & had no follow-up activity for at least 7 days are automatically locked. Please refer to our wiki for more details, including how to remediate this action if you feel this was done prematurely or in error: Issue List: Our approach to locked issues