Store data across multiple plot cards?

[FlorianOosterhof]

I have a concept for a dashboard for viewing and comparing heating efficiency over and between long periods of time. For this I need (statistic) history from a long period of time (multiple years) with high precision (daily at least, but preferably even hourly). I wish to have multiple graphs that post-process and slice this data in several ways.

One idea I had was to get the data once, store it in a global way (perhaps a web-page-wide or dashboard-wide JavaScript variable?) that is obtainable by all other cards. This because the data is simply very much, and obtaining it again for each card is costly in terms of time/responsiveness and bandwidth.

Is this possible?

[dbuezas]

It is but it will be a hack that may work a bit weird

In the first card write a function that puts the data inside window.my_data
Then in the others use empty strings for the entity and load the data from window

[dbuezas]

Exactly like that!
You could put this at the beginning of the first card:

fn: $ex window.my_vars = vars

And this in the following ones:

fn: $ex vars = window.my_vars

With that you can save/load data with the filters store_var. And load_var and that would act as a link.

Watch out though, the other cards won't know when to update so you may need to set refresh_interval: 10s on the other ones or something like that.
Maybe you could even make the interval variable depending on if the data was found or not (using $ex again)

[FlorianOosterhof]

Your construction with storing vars globally, will that depend on execution order? Or is this the kind of mechanism where vars is stored "by reference" in window, so that if vars is updated in the first card later on, it is automatically also updated in window.my_vars and thus in the other cards vars?

Or is it a copy, and thus execution-order dependent? In which case, is there any guarantee on said execution order?

[dbuezas]

it's by reference, so it is not important in the first card. It is important that it is very high in the other cards though.

I would just put that at the top on all of them so you don't have to think about it

[FlorianOosterhof]

I tried your suggestion, but it seems like it doesnt work as hoped. The second card is done plotting way before the first card is, probably because the first card is still receiving/parsing the data multiple years. I dont know how, but sometimes I manage to get the second card to replot, and then the data appears, so the data sharing works. But the second card should wait until the data is there. Do you know of a way to do that? I couldnt find a way for the JS to sleep, except an async one, but apparently this code is synchronous or I did something wrong.

[dbuezas]

Yeah, there are no hooks to trigger rerenders from the yaml or $ex. Everything except click handlers results in a single plain object that is passed to plotly and that's the end of it.

The only option you have is to make the second card poll until it has the data:

refresh_interval: |
   $ex window.my_vars ? '24h' : '1s'