Fix handling of the Toggle widget in a Param pane

[maximlt]

Fixes #1331

The panel widget Toggle was not synced like the other widgets in a Param pane:

panel/panel/param.py

Lines 378 to 379 in b73ec77

	if isinstance(widget, Toggle):
	pass

This special handling originated from #15 and was probably implemented this way because the widget that is created when one needs to expand a subparameter pane is a Toggle. I believe that now widgets created in a pane are given by _ordered_params() which do not expose that Toggle widget. So it's just fine to remove that special handling.

I also took advantage of this PR to fix a typo and improve the coverage of the param action test.

[codecov]

Codecov Report

Merging #1342 into master will increase coverage by 0.01%.
The diff coverage is 98.64%.

@@            Coverage Diff             @@
##           master    #1342      +/-   ##
==========================================
+ Coverage   87.49%   87.51%   +0.01%     
==========================================
  Files         130      130              
  Lines       13758    13759       +1     
==========================================
+ Hits        12038    12041       +3     
+ Misses       1720     1718       -2     

Impacted Files	Coverage Δ
panel/param.py	91.85% <98.50%> (+0.41%)	⬆️
panel/tests/test_param.py	99.85% <100.00%> (+<0.01%)	⬆️

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[philippjfr]

Thanks!

This special handling originated from #15 and was probably implemented this way because the widget that is created when one needs to expand a subparameter pane is a Toggle.

That is correct.

I believe that now widgets created in a pane are given by _ordered_params() which do not expose that Toggle widget. So it's just fine to remove that special handling.

That sounds right, but just to be sure do you know if this is currently under test and/or have you tested subobject toggling manually?

[maximlt]

Hi @philippjfr and thanks for your feedback,

I've tested it manually and saw nothing wrong.

Some of the current tests emulate a click on the toggle button, see for example:

panel/panel/tests/test_param.py

Line 666 in b6cf95f

test_pane._widgets['a'][1].value = True

I didn't have to change them so I assumed everything was alright.

If you'd like me to add another test that's OK. I'd just need some guidance as I don't really know how to check that. Could it be as fine grained as checking that there is just one callback on the toggle button?

[philippjfr]

I'm pretty sure it's fine too after looking at it so I'll merge. Thanks again!