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lastDataReceived

Observable liveness signal for the live data path.

Description​

Observe lastDataReceived to determine whether live panel data is actively arriving from the server, independently of what is rendered on screen. This is useful for diagnosing cases where polling has stalled or where data is being fetched but not displayed.

The field is published on every poll cycle while a panel session is active — both successful and failed requests emit a value. A run of ok: false entries is the intended signal for "no data arriving", not an error in the observer.

Nothing is published before polling starts. Polling requires both a resolved configuration and a valid player timecode, provided via onPlayerTimeCodeUpdated.

Type​

assocArray

Usage​

m.lib.observeField("lastDataReceived", "onLastDataReceived")

function onLastDataReceived(event as Object)
    data = event.getData()
    print "Live data poll: " + formatJson(data)
end function

Data Structure​

FieldTypeDescription
sourcestringWhich feed reported. Currently "overlay".
timecodestringPlayer timecode the poll was made against, or "" if none yet.
bytesintegerResponse body size in bytes. 0 when nothing came back.
okbooleantrue if the request succeeded; false otherwise.

Example​

sub setupLivenessMonitor()
    m.lib.observeField("lastDataReceived", "onLastDataReceived")
end sub

function onLastDataReceived(event as Object)
    data = event.getData()

    if data <> invalid then
        if data.ok = true
            print "Data received — source: " + data.source + ", bytes: " + data.bytes.toStr()
        else
            print "Poll failed — source: " + data.source
            ' Investigate connectivity or server availability
        end if
    end if
end function

Notes​

  • Polls run roughly every 10 seconds while a panel session is active.
  • Nothing is published before polling starts, which requires both a resolved configuration and a player timecode flowing via onPlayerTimeCodeUpdated.
  • Failed polls publish with ok: false and bytes: 0 — this is expected behavior indicating a failed poll, not a problem with the observer itself.
  • This field is inert when unobserved; no extra work is done by the SDK unless a handler is attached.
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