Ability for plugins to define extra JavaScript and CSS

[simonw]

This can hook in to the existing extra_css_urls and extra_js_urls mechanism:

datasette/datasette/app.py

Lines 304 to 305 in b2955d9

	'extra_css_urls': self.ds.extra_css_urls(),
	'extra_js_urls': self.ds.extra_js_urls(),

The plugins should be able to bundle their own assets though, so it will also have to integrate with the /static/ static mounts mechanism somehow:

datasette/datasette/app.py

Lines 1255 to 1257 in b2955d9

	app.static('/-/static/', str(app_root / 'datasette' / 'static'))
	for path, dirname in self.static_mounts:
	app.static(path, dirname)

Refs #14

[simonw]

Packaging JS and CSS in a pip installable wheel is fiddly but possible. http://peak.telecommunity.com/DevCenter/PythonEggs#accessing-package-resources

from pkg_resources import resource_string
foo_config = resource_string(__name__, 'foo.conf')

[simonw]

This looks like a good example: funkey/nyroglancer@d4438ab

[simonw]

resource_stream returns a file-like object which may be better for serving from Sanic.

[simonw]

I figured out the recipe for bundling static assets in a plugin: simonw/datasette-plugin-demos@26c5548 (and then python3 setup.py bdist_wheel)

Having done that, I ran pip install ../datasette-plugin-demos/dist/datasette_plugin_demos-0.2-py3-none-any.whl from my Datasette virtual environment and then did the following:

>>> import pkg_resources
>>> pkg_resources.resource_stream(
...    'datasette_plugin_demos', 'static/plugin.js'
... ).read()
b"alert('hello');\n"
>>> pkg_resources.resource_filename(
...    'datasette_plugin_demos', 'static/plugin.js'
... )
'..../venv/lib/python3.6/site-packages/datasette_plugin_demos/static/plugin.js'
>>> pkg_resources.resource_string(
...    'datasette_plugin_demos', 'static/plugin.js'
... )
b"alert('hello');\n"

[simonw]

One possible option: let plugins bundle their own static/ directory and then register themselves with Datasette, then have /-/static-plugins/name-of-plugin/... serve files from that directory.

[simonw]

Even if we automatically serve ALL static/ content from installed plugins, we'll still need them to register which files need to be linked to from extra_css_urls and extra_js_urls