Changing legacy visualization type doesn't update icon

[cjcenizal]

This may be related to #11242. This issue exists in 6.0.0.

If you create an area chart visualization and then change the type to "bar" under the Options tab, the "type" metadata for this visualization doesn't get updated, so an incorrect icon for the visualization is displayed on the landing page.

CC @bhavyarm

[ppisljar]

@snide should we have an icon for a mixed chart type (line + bar + area) or should we default to line in those mixed scenarios ?

[tsullivan]

I ran into this problem today and did some digging:

This seems to happen because there are different sources of the visualization type metadata:

• One is the visualization.visState which is a string field containing JSON. When the JSON is parsed to an object, that object has a type field. This is the field used to pick the icon in the visualization picker: https://github.com/elastic/kibana/blob/5.6/src/core_plugins/kibana/public/visualize/saved_visualizations/saved_visualizations.js#L30
• When visualization options change, it affects certain fields of the visState, but not the type. When you change a line chart to a bar chart, for example, it updates visState.params.seriesParams[n].type, where n is one of the multiple metrics shown on the chart.

There can be multiple metrics on a chart and they can have different types, which the "mixed" chart type that @ppisljar is referring to.

[ppisljar]

@tsullivan yeah icon changing is not implemented at all.
if we would implement it, on save we would check all the seriesParams[i].type and set the appropriate type` on the visState. We would then need this mixed option to represent charts with multiple series types.

[cjcenizal]

A user has reported this problem in 6.0.0-rc2: https://discuss.elastic.co/t/kibana-keeps-displaying-notice-about-area-charts-and-null-values-even-after-i-change-the-chart-type/107094/3

[thomai-d]

This bug is still present in 7.1.0

I created the chart as AreaChart initially, but changed it to a LineChart later:

[prabhakartalari]

May i know is there any solution. I am using Elastic 7.6.2 Version and could see the issue still exist.