Dashboard 2 persistent data in chart node

Dashboard
1

Is it possible to get persistent data during Node-RED restart/reboot in a dash2 chart node?

In the Dash1 I can use "node-red-contrib-persist" to store all chartdata and automatically reload on restart:

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It seems like Dash2/Chart only outputs every single msg received and not the complete chartdata like Dash1/Chart does.

This also makes each topic appear in a more or less random order when the chart is initialized which in turn changes pen colors to the order of which the dara reappears. This problem I have solved with a function sending dummy data with the correct topics on the correct order on reboot:

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This is usuallt no big deal but I have a few charts that have an x-axis span of 4 days and even one that is 6 weeks...

2

There is already a feature request for this. You could add your comments there.

3

Hi @joepavitt,

I think a native integration would be the best option for users. They will no longer need to go through a database or any other node.

NR offers an API to write and retrieve data: RED.storage.saveLibraryEntry

https://nodered.org/docs/api/storage/methods

I've never used it but in theory it should do the job.

4

Yeah, this has come up enough times now that we need to pay attention to it. For what it's worth, you can store all of your messages into a context variable or persisted file, and just pass an array of messages back into your chart - that will work, but is more manual that it needs to be.

2 Likes
5

Thanks all. I did a search before posting but didn't find any posts that I could recognise as a similar feature.

Looks like a solution is not too far in the future...