agronholm/aiohttp-apispec

Build and document REST APIs with aiohttp and apispec

aiohttp-apispec

Build and document REST APIs with aiohttp and apispec

aiohttp-apispec key features:

• docs, use_kwargs and marshal_with decorators to add swagger spec support out of the box
• validation_middleware middleware to enable validating with marshmallow schemas from those decorators

aiohttp-apispec api is fully inspired by flask-apispec library

Contents

• Install
• Quickstart
• Adding validation middleware
• Build swagger web client

Install

pip install aiohttp-apispec

Quickstart

from aiohttp_apispec import docs, use_kwargs, marshal_with, setup_aiohttp_apispec
from aiohttp import web
from marshmallow import Schema, fields


class RequestSchema(Schema):
    id = fields.Int()
    name = fields.Str(description="name")


class ResponseSchema(Schema):
    msg = fields.Str()
    data = fields.Dict()


@docs(tags=["mytag"], 
      summary="Test method summary", 
      description="Test method description")
@use_kwargs(RequestSchema(strict=True))
@marshal_with(ResponseSchema(), 200)
async def index(request):
    return web.json_response({"msg": "done", "data": {}})


app = web.Application()
app.router.add_post("/v1/test", index)

# init docs with all parameters, usual for ApiSpec
setup_aiohttp_apispec(
    app=app, title="My Documentation", version="v1", url="/api/docs/api-docs"
)

# now we can find it on 'http://localhost:8080/api/docs/api-docs'
web.run_app(app)

Class based views are also supported:

class TheView(web.View):
    @docs(
        tags=["mytag"],
        summary="View method summary",
        description="View method description",
    )
    @use_kwargs(RequestSchema(strict=True))
    @marshal_with(ResponseSchema(), 200)
    def delete(self):
        return web.json_response(
            {"msg": "done", "data": {"name": self.request["data"]["name"]}}
        )


app.router.add_view("/v1/view", TheView)

Adding validation middleware

from aiohttp_apispec import validation_middleware

...

app.middlewares.append(validation_middleware)

Now you can access all validated data in route from request['data'] like so:

@docs(
    tags=['mytag'],
    summary='Test method summary',
    description='Test method description',
)
@use_kwargs(RequestSchema(strict=True))
@marshal_with(ResponseSchema(), 200)
async def index(request):
    uid = request['data']['id']
    name = request['data']['name']
    return web.json_response(
        {'msg': 'done', 'data': {'info': f'name - {name}, id - {uid}'}}
    )

You can change Request's 'data' param to another with request_data_name argument of setup_aiohttp_apispec function:

setup_aiohttp_apispec(app=app,
                      request_data_name='validated_data',
                      title='My Documentation',
                      version='v1',
                      url='/api/docs/api-docs')
                      
...                  

@use_kwargs(RequestSchema(strict=True))
async def index(request):
    uid = request['validated_data']['id']
        ...

If you want to catch validation errors you should write your own middleware and catch web.HTTPClientError, json.JSONDecodeError and so on. Like this:

@web.middleware
async def my_middleware(request, handler):
    try:
        return await handler(request)
    except web.HTTPClientError:
        return web.json_response(status=400)
        
app.middlewares.extend([
    my_middleware,  # Catch exception by your own, format it and respond to client
    validation_middleware,
])

Build swagger web client

aiohttp-apispec adds swagger_dict parameter to aiohttp web application after initialization. So you can use it easily with aiohttp_swagger library:

from aiohttp_swagger import setup_swagger

...

async def swagger(app):
    setup_swagger(
        app=app, swagger_url='/api/doc', swagger_info=app['swagger_dict']
    )
app.on_startup.append(swagger)
# now we can access swagger client on /api/doc url