changed typecheck for list value to use isinstance instead of type

[kenshima4]

Solves: Layout as list of components does not work with Dash Pages page_container #2924

I've checked if the values passed to layout setter isinstance list, if so, set the values to html.Div (dash Component)

Contributor Checklist

• I have broken down my PR scope into the following TODO tasks
  • Set values passed as list to html.Div
  • Changed typecheck to use isintance instead of type
• I have run the tests locally and they passed (based on automated tests). (refer to testing section in contributing)
• I have added tests, or extended existing tests, to cover any new features or bugs fixed in this PR

optionals

• I have added entry in the CHANGELOG.md
• If this PR needs a follow-up in dash docs, community thread, I have mentioned the relevant URLS as follows
  • this GitHub #PR number updates the dash docs
  • here is the show and tell thread in Plotly Dash community

[gvwilson]

@T4rk1n this one looks good to me, but can you please check it before we merge?

[kenshima4]

Hi @gvwilson @T4rk1n, will fix the percy, testing etc this weekend. Will revert back.

[T4rk1n]

I'd rather see the check fixed than change the layout. The check at

dash/dash/dash.py

Line 2257 in bbd013c

if _ID_CONTENT not in self.validation_layout:

use a brittle/unoptimal API to check for ids that is outdated (doesn't work with component as props).

dash/dash/development/base_component.py

Line 366 in bbd013c

for t in self._traverse_ids():

The issue here is that we end up with a list of list so the traverse can't find it here:

dash/dash/dash.py

Lines 2250 to 2255 in bbd013c

	+ [
	# pylint: disable=not-callable
	self.layout()
	if callable(self.layout)
	else self.layout
	]

Need to extract the layout value then concat directly it if it's a list if not wrap in a list.

[kenshima4]

Hi @T4rk1n, I made the changes you recommended, please check. I'd just like to ask if all the integration tests need to remain unchanged or would I need to change them based on my changes?

Because I see even on dev branch the integration tests are failing (unless I'm wrong).
Can check with pytest -k test_cbcx005_grouped_clicks from dash directory.

Is this correct, or can I go ahead and modify these failing integration tests?

[T4rk1n]

💃 Looks good.

[gvwilson]

thanks @kenshima4 - @T4rk1n please merge whenever is convenient for you.

[kenshima4]

Hi guys, thanks for that! I am unsure why second round of testing didn't work. What I could see is the timestamps changing seem to have an effect on the testing suite. Please let me know if I'm missing something.