Missing Channels in Streaming Data JSON API Treated As NULL

[Optrix]

I'm using the streaming data API and have come across an annoyance. Some data sources are report-by-exception, in that they only send new data when the data changes.

Unfortunately, it seems that the streaming data API assumes that if you don't include a channel, it's null.

Ie, I have four channels set up - three temperatures and a date-stamp.

[{

    "Temp 1": "23",

    "Temp 2": "34",
    "Temp 3": "42",

    "Date": <valid datestamp>

}]

When I send that JSON, everything appears on live dashboards and reports.

If I send the following...

[{

    "Temp 2": "22",
    "Temp 3": "33",

    "Date": <valid datestamp>

}]

Then Temp 1 is marked as empty/null.

I understand why it works the way it does, but is there any option or facility anywhere to forward-fill missing data rather than setting it to null? Not all of our data points may update at the same rate, and we'd like to reduce traffic as much as possible by sending consolidated, minimised HTTP messages - re-sending old data seems quite a waste.

[v-yuta-msft]

@Optrix ,

I'm afraid currently there's no workaround. Power bi doesn't support forward-fill missing section in json. I would suggest you create an idea here to help power bi improve.

Regards,

Jimmy Tao