Docs: Dependency Injection

[filipvh]

Summary

https://docs.litestar.dev/2/usage/dependency-injection.html

I might (probably) be missing something, but I was wondering (seems to be no example) that if I inject a class into a controller. If in that class I can inject an other class?
So like i have a UserController and a UserService. But I also have a CommonService, that UserService wants to use.
Can and how would I do this. An example of this would be nice. Did i miss something?

[Alc-Alc]

Heya @filipvh, from what I understand you want a variant of what is shown here, I have slightly modified that example to use classes. Hope this solves what you are after. Worth noting is that, you should have the class you wish to inject be a parameter to __init__, then later use that where you want.

from litestar import Litestar, get
from random import randint


class FirstDependency:
    def do_something(self) -> int:
        return randint(1, 10)


class SecondDependency:
    def __init__(self, first_dependency: FirstDependency):
        self.first_dependency: FirstDependency = first_dependency

    def do_something_else(self) -> bool:
        return self.first_dependency.do_something() % 2 == 0


@get("/true-or-false")
async def true_or_false_handler(second_dependency: SecondDependency) -> str:
    return (
        "its true!" if second_dependency.do_something_else() else "nope, its false..."
    )


app = Litestar(
    debug=True,
    route_handlers=[true_or_false_handler],
    dependencies={
        "first_dependency": FirstDependency,
        "second_dependency": SecondDependency,
    },
)