RowColChart fails on edge cases where data is not available

[Brian Lewis]

this is typically due to timing issues, if the parent is waiting on a promise to assemble data for the chart.

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[Brian Lewis]

Solution strategy:

There must ALWAYS be a value for charttype: default = 'v' (stacked bar)

There must ALWAYS be a value for transofrmed data - incoming data should get transformed even if it is empty. That is , a ‘null’ dataset should get used for transform when the incoming data is null, undefined, {} or []

See also #852

[Brian Lewis]

fix:(charts): better handling of empty/undefined data

Resolves #851 #852

→ <<cset e4b6ad5a24cf>>