on product – > dashboard
if i load your devicePropertyWidget.html and i select HTML Widget
data_source: Manual 1
i can show ( value 1: and data {{source}}) but it don’t work
so if i select HTML Widget data_source: device_property
with device with my property testval {“a”:1234,“b”:667,“c”:0}
ok now i can show value , but {{source}} is empty
and don’t work
Indeed, the {{source}} will not be shown when using device_property, however it is still declared and you may access its details with its properties. For example: {{source.name}}
The error shown is normal, when you have it set to manual, there is no value.a field available.