Add stream decorator for HTTPMethodView

docs/sanic/streaming.md

@@ -35,9 +35,11 @@ async def index(request):
 
 Sanic allows you to get request data by stream, as below. When the request ends, `request.stream.get()` returns `None`.
 
-```
+```python
 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
 
@@ -45,6 +47,19 @@ bp = Blueprint('blueprint_request_stream')
 app = Sanic('request_stream', is_request_stream=True)
 
 
+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.stream('/stream')
 async def handler(request):
     async def streaming(response):
@@ -83,6 +98,7 @@ async def post_handler(request):
     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')