[Lens] Chart switcher does not preserve original axis dimensions depending on drop order

[dej611]

On the Lens editor, the order of axis/dimension assignment can lead to different results when switching from XY to pie and back XY.

Given the drop order: Horizontal -> Break down by -> Vertical, the Horizontal and Break down by dimension will be swapped when switching to a Pie chart. This becomes evident when returning to a XY chart again: Horizontal and Break down by fields are now swapped:

Given the drop order: Break down by -> Horizontal -> Vertical, the same route gives consistent results:

[elasticmachine]

Pinging @elastic/kibana-app (Team:KibanaApp)

[wylieconlon]

I thought we were already handling this logic, but it seems like it might not be correct. Basically the logic for selecting the axis should be:

• If there is exactly one histogram, that is the X axis regardless of order
• If there are no histograms, the X axis is the first bucketed agg
• If there are 2 histograms, the X axis is the first bucketed agg

Some examples in a table:

Order of aggs	X axis	Break down
Terms, Date histogram	Date histogram	Terms
Date histogram, terms	Date histogram	Terms
Number histogram, terms	Number histogram	Terms
Terms, number histogram	Number histogram	Terms
Terms, Filters	Terms	Filters
Filters, Terms	Filters	Terms
Number histogram, date histogram	Number histogram	Date histogram
Date histogram, number histogram	Date histogram	Number histogram

[flash1293]

Is it even possible to fix this bug with the state structure we have today? As the assignment of x and split dimensions can be changed by the user but we don't persist this choice when moving away from xy to pie, we have no way of always restoring the previous state when going back to xy.

So, just for clarification - do we want to make sure we always get back to the very same state or do we want to make it more likely by improving the assignment logic for x vs splitby?

[wylieconlon]

@flash1293 I don't think we can fully fix this bug for the reason you mentioned. I think the rules above will provide what users expect, because it's basically the existing logic for generating suggestions as part of the XY charts.

[dej611]

Should we close this as won't fix maybe?

[flash1293]

If we can confirm the rules from Wylies table are working (easy to check by going to table, configuring it, then switching to bar), I'm fine with closing this for now.

[stratoula]

Thank you for contributing to this issue, however, we are closing this issue due to inactivity as part of a backlog grooming effort. If you believe this feature/bug should still be considered, please reopen with a comment.