Things get rendered twice

[benfrancis]

When debugging the gateway front end I have noticed when that when the Things screen is loaded, the collection of Things is actually rendered twice. Each Thing is rendered in turn, then the view is cleared, then they are rendered again.

I also note that the /things resource is fetched three times, and /groups twice. Something is causing a refresh during page load.

STR:

• Load /things

Expected:

• /things and /groups resources loaded once
• Things rendered once

Actual:

• /things resource loaded three times
• /groups resource loaded twice
• Things rendered twice

[benfrancis]

I also note that on the thing detail view, the Thing gets rendered twice.

[benfrancis]

Ah, I've narrowed this down to https://github.com/WebThingsIO/gateway/blob/master/static/js/models/gateway-model.js#L149

refreshThings() is called both when the /things WebSocket is opened, and when the /groups WebSocket is opened.