Standard & Guidelines¶

Python¶

CraftBeerPi 4.x is based on Pyhton 3.7x. As a main framework CraftBeerPi is based on aiohttp

aioHTTP https://aiohttp.readthedocs.io/en/stable/

EventBus¶

One core concept of CraftBeerPi 4.x is the EventBus. It should be avoided to call method on a controller directly. Events should be fired and listener methods should be used. This makes sure that all components are loosely coupled. New plugins can listen on events and extend or change the functionality easily.

Here an example how to fire an event

cbpi.bus.fire(topic="notification/hello", key="hello", message="Hello World")

Here an example how listen on an event.

@on_event(topic="actor/+/switch/on")
def listener(self, id , power=100, **kwargs) -> None:
   pass

Note

It’s imporante to add **kwargs as parameter to the listening method. This makes sure that maybe addtional event paramenter are not causing an exception.

HTTP Endpoints¶

A new HTTP endpoints should be exposed by adding the @request_mapping decorator on top of an async method. The path parameter defines the URL path. The auth_required defines whether the endpoint should be accessible public or within a user session only. Typically you perform just some basing parameter validation and fire an event so that other components and controllers can perform some actions.

@request_mapping(path="/{id:\d+}/on", auth_required=False)
async def http_on(self, request) -> web.Response:
    self.cbpi.bus.fire(topic="actor/%s/switch/on" % id, id=id, power=99)
    return web.Response(status=204)

Note

The Events are process in an async way. Results will be pushed to the client via WebSocket Event.

WebSocket¶

The WebSocket is listening on http://<IP_ADDRESS>:<PORT>/ws All events are forwarded to all connected web socket clients.

The WebSocket Event is having the following structure.

topic -> is the bus topic
data -> the event data

{
   "topic":"notification/step",
   "data":{
      "key":"step",
      "message":"Hello World",
      "type":"info"
      }
}

Web User Interface¶

The Web UI is based on ReactJS + Redux. The build process is based on webpack and bable.

REST API¶

The REST API of CraftBeerPi is documented using Swagger.io After server startup you can find the API documentaiton under: http://<IP_ADDRESS>:<PORT>/api/doc

To generate the swagger file aiohttp-swagger is used. for more information see: https://aiohttp-swagger.readthedocs.io/en/latest/