Starlette Bridge¶

🚀 The Starlette events bridge that you need. 🚀

Documentation: https://starlette-bridge.tarsild.io 📚

Source Code: https://github.com/tarsil/starlette-bridge

Motivation¶

Starlette has evolved and it will keep on growing. In the release 0.26+ it was announced the on_startup and on_shutdown events would be removed in favour of the newly lifepsan and those would be officially removed in the release 1.0.

The problem is the fact that there are a lof od packages out there still using the old ways of using the events and this change will introduce breaking changes.

This bridge will make sure that doesn't happen and you can still use the old form of using the on_startup and on_shutdown without breaking the lifespan from Starlette.

What Starlette Bridge does for you is simple. It gets the on_startup and on_shutdown events in the same fashion you could do before and internally generates the newly lifespan for starlette.

That simple. Keeping the old syntax intact and using the newly lifespan.

Installation¶

To install Starlette Bridge, simply run:

$ pip install starlette-bridge

How to use¶

This is actually very simple to do it. You don't need to do anything particularly difficult, in fact, you only need to update where your Starlette object comes from.

from starlette_bridge import Starlette

app = Starlette()

And that is pretty much it.

How does it work¶

Starlette bridge simply maps your on_startup and on_shutdown events and converts them into the new lifespan async generator from Starlette.

This way you can continue to use your preferred way of assembling the events while maintaining the new structure required by Starlette for managing events.

on_event and add_event_handler¶

These two pieces of functionality are also supported by the bridge making sure that what you had in the past, still remains working as is without changing the syntax.

Let us see an example how it works. We will be using Starlette Bridge because already contains events we want to use.

on_startup/on_shutdown¶

Using the on_startup and on_shutdown.

from saffier import Database, Registry

from starlette_bridge import Starlette

database = Database("sqlite:///db.sqlite")
models = Registry(database=database)


app = Starlette(
    on_startup=[database.connect],
    on_shutdown=[database.disconnect],
)

Lifespan¶

You can, of course, use the lifespan as well.

from contextlib import asynccontextmanager

from saffier import Database, Registry

from starlette_bridge import Starlette

database = Database("sqlite:///db.sqlite")
models = Registry(database=database)


@asynccontextmanager
async def lifespan(app: Starlette):
    # On startup
    await database.connect()
    yield
    # On shutdown
    await database.disconnect()


app = Starlette(lifespan=lifespan)

on_event and add_event_handler¶

As mentioned before, those two functionalities are also available.

on_event¶

from saffier import Database, Registry

from starlette_bridge import Starlette

database = Database("sqlite:///db.sqlite")
models = Registry(database=database)


app = Starlette()


@app.on_event("startup")
async def start_database():
    await database.connect()


@app.on_event("shutdown")
async def close_database():
    await database.disconnect()

add_event_handler¶

from saffier import Database, Registry

from starlette_bridge import Starlette

database = Database("sqlite:///db.sqlite")
models = Registry(database=database)


app = Starlette()
app.add_event_handler("startup", database.connect)
app.add_event_handler("shutdown", database.disconnect)

Notes¶

This is from the same author of Esmerald, Saffier and Asyncz. Have a look around those techologies as well 😄.