Hooks Outside PiccoloCrud

[Fidel-C]

Just wondering whether Hooks can be emplemented externally in any part of the app. Something like Django signals. So that wherever a record changes or is added in the database, even if the action was called from the admin panel, the Hook would still be triggered . I think this restriction to PiccoloCrud alone is very limiting. I wish there could be a Django-like approach to this.

[dantownsend]

There isn't an official way of doing it at the moment - it's possible to override the save method on a table, but a bit tricky.

Having a proper API for it would be nice, as it's a much more common requirement than I expected.

[Fidel-C]

Looking forward to that then.

[Fidel-C]

A code example showing how to override the save method on a table will be good. I can't see how to that.

[dantownsend]

It's something like this:

from piccolo.utils.sync import run_sync

def save(self, columns=None):
    save_ = super().save

    class Save:
        async def run(self, *args, **kwargs):
            # Add custom logic here

            await save_(columns=columns).run(*args, **kwargs)

        def run_sync(self, *args, **kwargs):
            return run_sync(self.run(*args, **kwargs))

        def __await__(self):
            return self.run().__await__()

    return Save()

The reason it looks a bit complicated is because Piccolo lets you run a query as sync or async.

[Fidel-C]

Thanks a lot. I observed that the run method is called when adding records. But doesn't seem to be called when updating existing records.
Quite complicated, just like you said.

[sinisaos]

@Fidel-C You can also try something like this. It is based on the @dantownsend code with minor modifications to use (override) also save (both save and update) and remove methods.

[Fidel-C]

@sinisaos Thanks a lot.