Data Handling Requirements

Currently, we have two implemented chart engines that handle data in different ways, because assumptions were made differently at design time. To avoid this again, here are some data handling requirements that need to be addressed:

Requirement 1: Null or Empty Values

Today, we handle empty chart data values in two ways: we either plot the value as empty, which leaves a blank space on the chart where a data point would have been plotted, or we skip the null value completely and the chart is rendered as if the empty data value was not in the dataset at all.

We can:

Skip empty values and act as if they don't exist;
Plot empty values as a blank space;
Provide an option in the metadata to choose how empty values are handled, defaulting to plotting blank space.

This requirement should be specific for categorical charts, xy charts, time series charts and pie charts.