Add information message on monitoring parameters

[barbeau]

Summary:

Moved to a new issue from:
#286 (comment)

We need to add an informational component to provide feedback to users what parameters are being used for their monitoring session to explain to the user what's happening in the background for the shapes.txt processing and the set interval. This is because our server architecture has one thread monitoring each unique GTFS-realtime feed, so if someone starts monitoring a feed that someone else is already monitoring we have defined logic on whose settings win for interval and shapes.txt.

Here's an example informational message:

* {monitoring interval info here}
* {shapes info here}

Here's the logic for the monitoring interval:

• First bullet only appears if the user's interval selection is greater than the existing interval being used for monitoring. Text should be something like Monitoring interval is 5 seconds instead of 10 seconds because someone else is already monitoring this feed.

Here's the logic for the shapes.txt info message:

• If someone else is monitoring the feed already and their selection doesn't match the existing selection, it should read shapes.txt is {not} being used for GTFS-realtime rules because someone else is already monitoring this feed. Otherwise the bullet does not appear.

We need to define exactly where this message appears. Currently I'm thinking the top of the "Monitoring" page in a small banner at the top is the best location, as the shapes.txt and interval info could be passed back to the client from the call to GtfsRtFeed.startMonitor() API.

@Suryakandukoori Do you want to do a quick mockup of the UI for this before you actually implement?

Steps to reproduce:

Set the shapes.txt and interval options in the web UI and start monitoring

Expected behavior:

Tell me what parameters are actually being used to monitor the feed if another user already set parameters for the same feed.

Observed behavior:

There is no way to know via the UI what actual parameters are being used if they conflicted with another user's parameters.

Platform:

N/A