Registering new Datasette plugin hooks by defining them in other plugins#

I’m experimenting with a Datasette plugin that itself adds new plugin hooks which other plugins can then interact with.

It’s called datasette-low-disk-space-hook, and it adds a new plugin hook called low_disk_space(datasette), defined in the datasette_low_disk_space_hook/hookspecs.py module.

The hook is registered by this code in datasette_low_disk_space_hook/__init__.py

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from datasette.utils import await_me_maybe
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from datasette.plugins import pm
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from . import hookspecs
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pm.add_hookspecs(hookspecs)

This imports the plugin manager directly from Datasette and uses it to add the new hooks.

I was worried that the pm.add_hookspects(hookspecs) line was not guaranteed to be executed if that module had not been imported.

It turns out that having this entrpoints= line in setup.py is enough to ensure that the module is imported and the pm.add_hookspecs() line is executed:

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from setuptools import setup
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setup(
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    name="datasette-low-disk-space-hook",
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    # ...
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    entry_points={"datasette": ["low_disk_space_hook = datasette_low_disk_space_hook"]},
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    # ...
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)