@waaren
Exactly same argument (= limited daily free allowance for calls) at my side to have OpenUV called only by one application, and then source-information locally available for all other users, including possibility to directly read the JSON-file.
In lua I would use a scriptline to set the required properties/attributes for the JSON-file, like
Code: Select all
os.execute("chmod a+rw /path/filename.txt")
After check, that construction also seems valid for dzVents.

waaren probably has more clever (=shorter&general) solution, but this line added to the snippet makes the specific JSON-file accessible for all users
Code: Select all
os.execute("chmod a+rw /home/pi/domoticz/scripts/dzVents/data/OpenUV.json")
Addition 2020June03:
The JSON-file is the extended source for info available from OpenUV.
By changing the attribute in the scriptline from 'a ' to 'w+' (is 'append-mode' versus 'rewrite'-mode), you get only the latest issue of the JSON-file, not the whole collection.
Code: Select all
local f = io.open(dz.data.openUV_Filename, 'w+')

For getting the 'elementary' UV-info it is much easier to install the plugin (but you have to be aware that each computer-with-plugin needs it's own API-key from OpenUV, because otherwise you are quickly consuming your daily free allowance of calls) ......