Add stream for CompositionView

docs/sanic/streaming.md

@@ -37,6 +37,7 @@ Sanic allows you to get request data by stream, as below. When the request ends,
 
 ```
 from sanic import Sanic
+from sanic.views import CompositionView
 from sanic.blueprints import Blueprint
 from sanic.response import stream, text
 
@@ -71,7 +72,20 @@ async def bp_handler(request):
         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)
+view = CompositionView()
+view.add(['POST'], post_handler, stream=True)
+app.add_route(view, '/composition_view')
 
 
 if __name__ == '__main__':