Performance improvement on (pattern-matching) callbacks

[Spriteware]

This PR is related to the issue I described here : #3008
If I encountered performance limitation with pattern-matching callbacks, I think this PR can be beneficial for regular callbacks as well.

Contributor Checklist

• I have broken down my PR scope into the following TODO tasks
  • task 1
  • task 2
• I have run the tests locally and they passed. (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

[chriddyp]

Awesome investigation @Spriteware , and an impressive first PR! Thank you for digging in here 🌟

[T4rk1n]

There seems to be a side effect on the test:

dash/components/dash-core-components/tests/integration/graph/test_graph_varia.py

Line 684 in ef00323

def test_grva008_shapes_not_lost(dash_dcc):

The calls on lines

dash/components/dash-core-components/tests/integration/graph/test_graph_varia.py

Lines 716 to 721 in ef00323

	dash_dcc.wait_for_text_to_equal("#output", "0")
	# Draw a shape
	dash_dcc.click_and_hold_at_coord_fractions("#graph", 0.25, 0.25)
	dash_dcc.move_to_coord_fractions("#graph", 0.35, 0.75)
	dash_dcc.release()

happens before the graph render.
If you add a time.sleep before the Draw a shape, it passes the test.

I think before this fix the dash_dcc.wait_for_text_to_equal("#output", "0") may have taken longer which allowed the graph to render.

[T4rk1n]

Let's just add: dash_dcc.wait_for_element("#graph .js-plotly-plot") after

dash/components/dash-core-components/tests/integration/graph/test_graph_varia.py

Line 716 in ef00323

dash_dcc.wait_for_text_to_equal("#output", "0")

and it will fix the test.

Then it's just missing a changelog entry and it's good to go 🚀

[Spriteware]

Hey @T4rk1n thank you for digging into the failing dcc tests. I wasn't sure what to do, as the main dash tests were passing locally. And not sure if I had the time and energy to go through this as well.

Excited if this gets merged!

@chriddyp Thank you for your supportive comment. If you need more investigations for optimizations, my DMs on plotly forum are indeed opened.

[T4rk1n]

💃 Looks good, thank you.

[emilhe]

This is amazing @Spriteware ! This issue has annoyed me for ages. I can't wait for the next release 👯