onclick pop-up with time series via `getFeatureInfo`

[opeeters]

Currently, when clicking on a station, you get e.g. this:

When clicking in between stations, this pop-up generated via L.WMS is empty:

Instead, the click-event could trigger a graph generation (concentration versus time) for interval:

• hmean & 24hmean: last 24 hours
• dmean: 7 days
• anmean: 5 years

Example getFeatureInfo:

• https://geo.irceline.be/rioifdm/wms?service=WMS&request=GetFeatureInfo&version=1.1.1&layers=rioifdm:no2_hmean&info_format=application/json&time=2020-01-10T11:00:00.000Z&width=1&height=1&srs=EPSG:4326&bbox=4.36743669338796,50.843660899999996,4.36744669338796,50.8436709&query_layers=rioifdm:no2_hmean&X=1&Y=1

[stevenvdbosch]

@opeeters as library we could use chart.js. I've made a small sample: https://jsfiddle.net/vf2okq8y/

As estimation i would say 2 days. It seems fairly easy to make a single chart, but we should take in to account:

• to make it generic
• to test this feature with the different time intervals
• there is probably some communication needed for the exact styling of this graph (cfr options like "linetension",..)

Some initial questions: Can you inform me about how to use the getFeatureInfo service? Can i give a bbox of 2 times the point where was clicked? or does it need to be an enclosing bbox? Is it possible to get multiple times in one request? or do we have to do really 24 requests (for the 24 different hours) for hmean? (this seems a lot and rather inefficient)