Fixed issues I experienced in OctoPrint from Version 1.4.2 to 1.5.2.

Fixes:

"chamber" temperature showing up with no chamber configured (by ignoring entries whichs temps are null) (https://github.com/jneilliii/OctoPrint-PlotlyTempGraph/issues/3)
Temperatures not showing up after Re-Connect of printer or if not using 'Auto-Connect on server startup' (https://github.com/jneilliii/OctoPrint-PlotlyTempGraph/issues/1)
Custom Temperatures not showing up in certain scenarios (by adding null checks) (https://github.com/jneilliii/OctoPrint-PlotlyTempGraph/issues/2)
Having to restart Octoprint to make Graphs which were added at runtime show up (https://github.com/jneilliii/OctoPrint-PlotlyTempGraph/issues/2)

All these basically resolve to:

Changes:

I added null / undefined checks to fromHistoryData and plotTraces which solved the issues
I added debug and error logs to functions that were causing troubles
- Debug Logs can be enabled by setting self.debugLogs = true;, error logs are always enabled

Known Issues:

Does not solve Issue https://github.com/jneilliii/OctoPrint-PlotlyTempGraph/issues/2 completly
- New Temps which are added during runtime only show up during a single update and disappear again. The User needs to refresh the page (F5) to see the new graphs permanently. But a restart of Octoprint is not required anymore.
The default value of 0 for y_data in fromHistoryData renders the graph at 0 until data is available. It would be more desirable to have no data-point (x and y) at all in these cases. But this version works for now.

jneilliii / OctoPrint-PlotlyTempGraph