Clicking on some measurements on the map result in an error

[Piiit]

I logged in as a user that can access "Comune di Bolzano" data, then I clicked on "traffic" and the station as you see it in the screenshot:

The problem is that the detail view shows "loading..." forever. All data types in that station that have a gray dot work as expected.

Console output is as follows:

Uncaught (in promise) TypeError: station_data_json.data[stationType] is undefined
    setupFeatureClickPopup map.js:461
    e events.js:41
    dispatchEvent Target.js:101
    handleMapBrowserEvent PluggableMap.js:927
    e events.js:41
    dispatchEvent Target.js:101
    emulateClick_ MapBrowserEventHandler.js:119
    handlePointerUp_ MapBrowserEventHandler.js:175
    e events.js:41
    dispatchEvent Target.js:101
    fireNativeEvent PointerEventHandler.js:397
    an NativeSource.js:64
    eventHandler_ PointerEventHandler.js:203
    e events.js:41
    v events.js:174
    addEvents_ PointerEventHandler.js:214
    addEvents_ PointerEventHandler.js:213
    register_ PointerEventHandler.js:176
    registerSources PointerEventHandler.js:141
    e PointerEventHandler.js:115
    handlePointerDown_ MapBrowserEventHandler.js:217
    e events.js:41
    dispatchEvent Target.js:101
    fireNativeEvent PointerEventHandler.js:397
    on NativeSource.js:44
    eventHandler_ PointerEventHandler.js:203
    e events.js:41
    v events.js:174
    addEvents_ PointerEventHandler.js:214
    addEvents_ PointerEventHandler.js:213
    register_ PointerEventHandler.js:176
    registerSources PointerEventHandler.js:141
    e PointerEventHandler.js:115
    e MapBrowserEventHandler.js:78
    e PluggableMap.js:290
    e Map.js:75
    map_start_promise map.js:78
    <anonymous> (index):119
map.js:461:26

[Piiit]

@rcavaliere FYI

@davidebz Do you have an idea how to solve this?

[noctho]

The problem is that the code expects a result from the following request, but the data property is empty:

https://mobility.api.opendatahub.testingmachine.eu/v2/tree/TrafficSensor/*?where=scode.eq.municipalitybz:14

But the result of this request is not empty:

https://mobility.api.opendatahub.testingmachine.eu/v2/tree/TrafficSensor?where=scode.eq.municipalitybz:14

Therefore, I assume that the station "municipalitybz:14" does not contain any data type.

As you can see, the station "municipalitybz:14l2d1" contains some data types:

https://mobility.api.opendatahub.testingmachine.eu/v2/tree/TrafficSensor/*?where=scode.eq.municipalitybz:14l2d1

Would it be possible to change the API to return the station metadata with an empty sdatatypes array when a station does not contain a data type? That would solve this problem. Otherwise we have to send another request in order to show the metadata of the station in this case.

[Piiit]

@noctho Hi, thanks for your investigations.

However, the API operates like a SQL statement as it is just a thin layer around Postgres queries. That is, if you have a filter that filters out everything, nothing is generated and an empty result returned. Checking the DB it turns out that that station has no measurements attached, hence the empty result.

I will think of a possibility to add empty sdatatypes, but that will not happen in short time. I have to rethink how the API works internally and see if I could make a left outer join, but I do not know what implications that might have for performance and other results. It should be possible for a v3 of the API thou.

So please, fix the logic inside your code in the meantime.

[rcavaliere]

This is a special case of stations that have no data types and measurements associated. Yes, if we have a better error message here would be nicer.