hi, I'm trying to save and read chart data into a context var. I'v edited the setting.js file to save the context variables into a file. In this example flow I inject random numbers to a chart and save them to a Global variable. my goal is to load all the data before the power outage and continu…

found a solution: I've added a switch node after the Chart node and my function node: that states if msg.payload is undefined don't save it. [flow] thank you very much for your help.

Show us what you have done in settings.js

// Context Storage // The following property can be used to enable context storage. The configuration // provided here will enable file-based context that flushes to disk every 30 seconds. // Refer to the documentation for further options: https://nodered.org/docs/api/context/ // contextStorage…

Also put a debug node on the output of the function node picking up the data and see what it shows. Does the chart restore if you restart node-red without rebooting?

yes, the chart is restored without rebooting. this is the output from the function node: msg.payload : array[1] array[1] 0: object series: array[1] 0: "" data: array[1] 0: array[5] 0: object 1: object 2: object 3: object 4: object

Is that what the function node shows after boot? If so then it does not appear to be empty.

this was the debug Without rebooting as you requested. After reboot I get a "msg.payload undefined" reply.

OK, that isn't what I meant, but I see my message was ambiguous. What time range have you specified in the chart? Try building a chart then remove the wire out of the chart and deploy. The chart should re-draw. Restart node red and make sure it still redraws. Then stop node-red from starting on…

dear Colin, Let me clarify: All injected values are stored in the Global.json file in a variable. I've checked the Global.json file after a reboot and the variable is there and contains data. Whenever the Chart is empty (via reboot or by msg.payload= []) and when I inject the saved data from t…

[image] Ki-va: when I inject the saved data from the Global.json file variable the variable is deleted, After checking the data is there, but before injecting it, remove the wire coming out of the chart and deploy. That will prevent the chart output from affecting the stored data. Then try…

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Restore Chart data after power outage

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Ki-va 30 June 2020 10:25 11

when I removed the wire coming out of the chart, and deploing,
the data is still stored in the Global.json and appears in the chart.

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Restore Chart data after power outage

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