Poll alerts #1291
Poll alerts #1291
Conversation
lib/signs_ui/alerts/state.ex
Outdated
| defp update_state(%Event{event: "add", data: data}, state) do | ||
| alert = Events.parse(data) | ||
| Map.put(state, alert.id, alert) | ||
| def parse(payload) when is_map(payload) do |
There was a problem hiding this comment.
nit: Since these parse functions operate on different levels of the data structure, it might be slightly clearer to give them distinct names rather than implicitly differentiating by type. (And/or combine some of them)
| "filter[route_type]" => "0,1" | ||
| } | ||
| ) do | ||
| {:ok, %HTTPoison.Response{status_code: 200, body: body}} -> |
There was a problem hiding this comment.
Due to load balancing/caching, the API can sometimes return slightly older data on subsequent calls, which means that unless we track Last-Modified, we could see this state briefly "out of order" around transitions. That's probably fine for this case, since this data doesn't change very often, and it only populates the form UI, but I wanted to call it out.
| Display.format_state(new_state) | ||
| ) | ||
|
|
||
| Logger.info(["alert_state_updated ", inspect(new_state)]) |
There was a problem hiding this comment.
note: This now logs every 5 seconds, regardless of whether there was a change. If we have any reports tied to this, we may need to update them.
Summary of changes
Asana Ticket: Rework Signs UI to direct poll for alert events
Replace the use of
GenStageand Server Sent Events with polling the V3 API every 5 seconds for alerts data. With SSE, the events occasionally would stop coming through for a reason we were not able to pin down. Since Signs UI doesn't need to be fully "real-time", swapping out SSE for some simple polling should be more straightforward and reliable.