Regression with scroll to command in colab

[richard-to]

Using mel.chat just hangs when sending a message. This is due to the scrollto command. We recently updated it to use afterRender (#1182), but for some reason the afterRender is not being triggered in colab.

If you remove the scrollto in mel.chat, it works (https://github.com/google/mesop/blob/main/mesop/labs/chat.py#L168.)

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Expected behavior is that mel.chat scrolls down and prints response message.

[wwwillchen]

When you say hang, do you mean it doesn't scroll or the python program is stuck?

If it's not scrolling, this isn't too bad, I tried running our colab https://colab.research.google.com/github/google/mesop/blob/main/notebooks/mesop_colab_getting_started.ipynb#scrollTo=JhgA_hFbQFCl with the latest (non-pre-release) version and scroll into view doesn't seem to work either so I'm not sure if that's a regression.

I am seeing, when running colab with the latest pre-release version, the following error:

Could not scroll to component with key scroll-to because no component found

I can see in the stacktrace that maybeExecuteScrollCommand is actually being executed but it's not actually scrolling because it's not finding the component.

Still not sure though why it's not working.

[richard-to]

They said the program basically was stuck. But when they click fullscreen, it updated, so that does seem to indicate a potential issue with afterRender in some way.