"""

This example demonstrates model signals usage

"""

from typing import List, Optional, Type

from tortoise import BaseDBAsyncClient, Tortoise, fields, run_async

from tortoise.models import Model

from tortoise.signals import post_delete, post_save, pre_delete, pre_save

class Signal(Model):

id = fields.IntField(pk=True)

name = fields.TextField()

class Meta:

table = "signal"

def __str__(self):

return self.name

@pre_save(Signal)

async def signal_pre_save(

sender: "Type[Signal]", instance: Signal, using_db, update_fields

) -> None:

print(sender, instance, using_db, update_fields)

@post_save(Signal)

async def signal_post_save(

sender: "Type[Signal]",

instance: Signal,

created: bool,

using_db: "Optional[BaseDBAsyncClient]",

update_fields: List[str],

) -> None:

print(sender, instance, using_db, created, update_fields)

@pre_delete(Signal)

async def signal_pre_delete(

sender: "Type[Signal]", instance: Signal, using_db: "Optional[BaseDBAsyncClient]"

) -> None:

print(sender, instance, using_db)

@post_delete(Signal)

async def signal_post_delete(

sender: "Type[Signal]", instance: Signal, using_db: "Optional[BaseDBAsyncClient]"

) -> None:

print(sender, instance, using_db)

async def run():

await Tortoise.init(db_url="sqlite://:memory:", modules={"models": ["__main__"]})

await Tortoise.generate_schemas()

# pre_save,post_save will be send

signal = await Signal.create(name="Signal")

signal.name = "Signal_Save"

# pre_save,post_save will be send

await signal.save(update_fields=["name"])

# pre_delete,post_delete will be send

await signal.delete()

if __name__ == "__main__":

run_async(run())