Check for Existence of UV and Solar Radiation Sensors

[Gary Roderick]

wdtags.py returns None for the corresponding tag(s) if UV or solar radiation sensors are not installed. wdtags.py needs to return something other than None or the clientrawextra template needs to be able to handle these tags being returned with a value of None.

[Oz Greg]

Started Work on this by Adding 3 new Extra Tags to the skin.conf.. We should now be able to use IF statements to Control UV Calculations..

[Gary Roderick]

Testtags.php.tmpl only uses native Weewx ($current, $day, .max, .maxtime etc) and custom 'ago' radiation/UV tags. Both Weewx native and 'ago' tags return 'None' if sensor is not present hence .has_data can be/has been used to check if valid radiation/UV data is present. All testtags.php.tmpl radiation/UV related tags are well behaved in the absence of radiation and/or UV sensors.

[Gary Roderick]

All templates now have a mechanism to handle absence or solar/radiation and/or UV readings. Solar and UV flags have been removed from skin.conf files