tomwojcik/starlette-context

Can't write new plugin - plugin is not iterable

dddenes opened this issue · 4 comments

dddenes commented

Hi!

I am quite new to Starlette and FastAPI, and I might have holes in my knowledge, however I was not able to write a new plugin.

from fastapi import FastAPI
from fastapi.middleware import Middleware

from starlette_context.header_keys import HeaderKeys
from starlette_context.plugins import Plugin

class LangPlugin(Plugin):
    print('****')

middleware = [
    Middleware(
        RawContextMiddleware,
        plugins(
            LangPlugin()
        )
    )
]

app = FastAPI(middleware=middleware)

And it says:

  File ".../starlette_context/middleware/raw_middleware.py", line 17, in __init__
    if not all([isinstance(plugin, Plugin) for plugin in self.plugins]):
TypeError: 'LangPlugin' object is not iterable

How is my plugin not instance of Plugin, I wonder. Or I guess this is the problem.

To put you into context, I would like to get from here an optional string param, (/path-to-api-endpoint/?lang=en) to access the request language from everywhere. Or maybe you have a more straightforward solution to my problem, what I did not recognize?

tomwojcik commented

You're missing =.

Change

middleware = [
    Middleware(
        RawContextMiddleware,
        plugins(
            LangPlugin()
        )
    )
]

to

middleware = [
    Middleware(
        RawContextMiddleware,
        plugins=(
            LangPlugin()
        )
    )
]
  • 👍1
dddenes commented

Sorry for the wrong "copy-paste", the = after the plugins lost somewhen, when I minimalized the problem. I have it, and if I remove it, I get a different TypeError: 'module' object is not callable.
So the middleware what you wrote above looks just like mine right now, and I still get TypeError: 'LangPlugin' object is not iterable.

tomwojcik commented

One element tuple need a comma to still be a tuple. Add comma after LangPlugin.

middleware = [
    Middleware(
        RawContextMiddleware,
        plugins=(
            LangPlugin(),
        )
    )
]
  • 🎉2
dddenes commented

Ahh, I go hide somewhere, user error indeed. Thank you for your patience!

  • 👍1