Add optional React 16 support

[mjclawar]

Description

This adds optional React 16 support by allowing the developer to modify the React version served using, e.g.:

import dash_renderer
dash_renderer.REACT_VERSION = '16.2.0'

The default REACT_VERSION remains 15.4.2

Other changes

• Updated .eslintignore to ignore all minified react bundles (versus just 15.4.2)
• Bumped version to 0.12.0

[utyf]

The mechanism of choosing version is not clear.
When you execute import dash_renderer file dash_renderer/__init__.py is executed and version is set to '15.4.2'.
If you set REACT_VERSION to '16.2.0' later on the next line, this has no effect.

[mjclawar]

@utyf You're totally right. I just realized this last night. I'm going to close this PR for now. There's another (ugly) monkeypatch example in this PR: plotly/dash-core-components#160

[utyf]

maybe we need to do something like this:

def _set_react_version(react_version):
    assert react_version in _REACT_VERSION_TYPES
    # Dash renderer's dependencies get loaded in a special order by the server:
    # React bundles first, the renderer bundle at the very end.
    setattr(_this_module, '_js_dist_dependencies', [{
        'external_url': _REACT_VERSION_TO_URLS[react_version]['external_url'],
        'relative_package_path': _REACT_VERSION_TO_URLS[react_version]['relative_package_path'],
        'namespace': 'dash_renderer'
    }])

    setattr(_this_module, '_js_dist', [{
        'relative_package_path': 'bundle.js',
        "external_url": (
            'https://unpkg.com/dash-renderer@{}'
            '/dash_renderer/bundle.js'
        ).format(__version__),
        'namespace': 'dash_renderer'
    }])

_set_react_version('15.4.2')

and then, in the code:

import dash_renderer
dash_renderer._set_react_version('16.2.0')

[mjclawar]

That works. Adding and reopening with that. From the updated CHANGELOG:

Allows user to now choose between '15.4.2' and '16.2.0' for React versions

import dash_renderer

# Set the react version before setting up the Dash application
dash_renderer._set_react_version('16.2.0')

app = dash.Dash(...)

All previous tests still pass. Added another test to make sure that this actually updates the React version for a dash.Dash application initialized after dash_renderer._set_react_version has been called

Thanks, @utyf !

[chriddyp]

This looks good to me! Thank you very much for adding the test. Anything else you would like to add @mjclawar before I merge?

[mjclawar]

@chriddyp no I think this covers everything as long as you are OK with the dash_renderer._set_react_version method!

Probably also will want to bump the default minimum React version to 15.6 soon to at least warn other dash component authors about PropTypes before ideally moving entirely to 16. Not sure if you want a more rigorous roadmap about updating dash-renderer React versions.

[mjclawar]

@chriddyp anything else you need to see on this?

[utyf]

Any news on the topic?

[mjclawar]

@chriddyp Checking in to see if you want anything else here to accept the PR.

We're looking forward to using React 16 for all our Dash applications!

[chriddyp]

Sorry for the delay on this one! This looks good to me, I'll merge now and press a new release 🍻

[chriddyp]

just published: pip install dash-renderer==0.12.0