Flask integration

Installation

pip install "django-autowired[flask,injector]"

Direct init

from flask import Flask
from django_autowired.integrations.flask import Autowired

app = Flask(__name__)
Autowired(app, packages=["myapp.services"], backend="injector")

Application factory pattern

from flask import Flask
from django_autowired.integrations.flask import Autowired

autowired = Autowired(packages=["myapp.services"])

def create_app() -> Flask:
    app = Flask(__name__)
    autowired.init_app(app)
    return app

Args passed to init_app() take precedence over constructor args:

aw = Autowired(packages=["wrong"], backend="lagom")
aw.init_app(app, packages=["myapp"], backend="injector")   # these win

Resolving dependencies in route handlers

Use inject_dep(cls):

from flask import Flask
from django_autowired.integrations.flask import inject_dep
from myapp.services.greeter import GreetingService

@app.route("/greet/<name>")
def greet(name: str):
    svc = inject_dep(GreetingService)
    return svc.greet(name)

Full example

# app.py
from abc import ABC, abstractmethod
from flask import Flask
from django_autowired import injectable
from django_autowired.integrations.flask import Autowired, inject_dep


class IGreeter(ABC):
    @abstractmethod
    def greet(self, name: str) -> str: ...


@injectable(bind_to=IGreeter)
class FriendlyGreeter(IGreeter):
    def greet(self, name: str) -> str:
        return f"hi, {name}!"


app = Flask(__name__)
Autowired(app, packages=["__main__"], backend="injector")


@app.route("/greet/<name>")
def greet(name: str):
    return {"message": inject_dep(IGreeter).greet(name)}


if __name__ == "__main__":
    app.run()