Add Request.stream

[38elements]

This adds Request.stream and stream decorator, as below.

from sanic import Sanic
from sanic.views import CompositionView
from sanic.views import HTTPMethodView
from sanic.views import stream as stream_decorator
from sanic.blueprints import Blueprint
from sanic.response import stream, text

bp = Blueprint('blueprint_request_stream')
app = Sanic('request_stream')


class SimpleView(HTTPMethodView):

    @stream_decorator
    async def post(self, request):
        result = ''
        while True:
            body = await request.stream.get()
            if body is None:
                break
            result += body.decode('utf-8')
        return text(result)


@app.post('/stream', stream=True)
async def handler(request):
    async def streaming(response):
        while True:
            body = await request.stream.get()
            if body is None:
                break
            body = body.decode('utf-8').replace('1', 'A')
            response.write(body)
    return stream(streaming)


@bp.put('/bp_stream', stream=True)
async def bp_handler(request):
    result = ''
    while True:
        body = await request.stream.get()
        if body is None:
            break
        result += body.decode('utf-8').replace('1', 'A')
    return text(result)


async def post_handler(request):
    result = ''
    while True:
        body = await request.stream.get()
        if body is None:
            break
        result += body.decode('utf-8')
    return text(result)

app.blueprint(bp)
app.add_route(SimpleView.as_view(), '/method_view')
view = CompositionView()
view.add(['POST'], post_handler, stream=True)
app.add_route(view, '/composition_view')


if __name__ == '__main__':
    app.run(host='127.0.0.1', port=8000)

[r0fls]

does this replace #696?

[38elements]

I am sorry.
Yes, this does.

[r0fls]

why is this needed? 🤔

[38elements]

request handler replaces '1' with 'A'.
This makes the correct result.

[38elements]

Thank you for reviewing.
I removed replacing '1' with 'A'.

[r0fls]

I think it makes more sense to set self.is_request_stream = True in the app.stream method, if used. This would avoid having to initialize it here.

[r0fls]

So around line 170

[38elements]

I think your pointing out is correct.
I think it is better to add self.is_request_stream = True in app.route() for blueprint.stream().

if stream:
    self.is_request_stream = True

[38elements]

There is a bug.
This can not use CompositionView and HTTPMethodView.

AttributeError: 'function' object has no attribute 'is_stream'

I will fix it and add tests.

[38elements]

I add stream in composition_view.add() and test for CompositionView and HTTPMethodView.

[38elements]

I am sorry for adding code.
I added stream decorator for HTTPMethodView.

[38elements]

There is a bug.
CompositionView and HTTPMethodView can not set self.is_request_stream = True.
It is necessary to set True to self.is_request_stream in app.add_route() for CompositionView and HTTPMethodView .
I will fix it and add tests.

[38elements]

I fixed it and added tests.

[seemethere]

So instead of it's own decorator wouldn't it make sense to make it as just a parameter that you can pass in through the regular method decorators?

Example:

@app.post('/help/<id>', stream=True)
def stream_handler(request):
    pass

Not necessarily a show-stopper just asking the question.

Great work as always @38elements

[38elements]

Thank you for reviewing.
Since I think it is more consistent, I think it is better stream parameter than stream decorator.
I will delete stream decorator and add stream parameter and change tests.

[38elements]

I replaced stream decorator to stream parameter.
Only post, put and patch decorator have stream argument.

[seemethere]

Will merge once I create a milestone for this

[38elements]

Thank you.

[38elements]

I added a heading in streaming.md.

[r0fls]

we should also remove this from the todo here: https://github.com/channelcat/sanic/blob/master/README.rst#todo

[38elements]

@r0fls
I think the line should be removed by #733.

[gsvijayraajaa]

Trying to execute the code shared by @38elements .
Getting the error:

from sanic.views import stream as stream_decorator
ImportError: cannot import name 'stream'

Is the code merged to master ?