Refactor JSON encoding to use plotly.py JSON engine

[jonmmease]

Update to make Dash use the active plotly.py JSON engine. The JSON engine system was introduced in plotly.py in plotly/plotly.py#2955.

Note: This PR adds a plotly.py lower version bound of 5.0.

plotly.py will use the faster orjson encoder by default if the orjson package is installed. But to make the orjson engine is in use, add this snippet:

import plotly.io as pio
pio.json.config.default_engine = "orjson"

[jonmmease]

There is one percy baseline change. The plotly.py JSON engines always sort object keys in alphabetical order. So the devtools validation exception snapshot changed.

Before:

label/value/typo

After:

label/typo/value in alphabetical order

[jonmmease]

Ready for review

[alexcjohnson]

Add a changelog entry and this is great! 💃

There are also a couple instances of PlotlyJSONEncoder in the tests, do you want to convert these too?

[alexcjohnson]

Oh actually I don't see orjson listed as a dep, were you going to include it in requires-dev.txt? Can we perhaps pick one or two integration tests and run them with both json and orjson? I don't care which, they all make extensive use of JSON encodings :)

[jonmmease]

Thanks! Yeah, I'll make sure both get used in some tests.

[jonmmease]

Can we perhaps pick one or two integration tests and run them with both json and orjson? I don't care which, they all make extensive use of JSON encodings :)

Yeah, I added it to requires-dev.txt and made a couple of tests run with both encoders (a167542)

There are also a couple instances of PlotlyJSONEncoder in the tests, do you want to convert these too?

I decided not to as a small extra check for backward compatibility. But it wouldn't take much to talk me into it 🙂

Changelog entry added in (53419b0)

[jonmmease]

ping @alexcjohnson or @chriddyp. This is ready to merge, but I don't have permission to approve the percy diff mentioned above. Could one of you approve that in percy?

[chriddyp]

Approved, looks good!

[jonmmease]

Thanks!