public class CategoryDataItem
extends DataItem

CategoryDataItem A CategoryDataItem extends the base DataItem class and is used for various charts including BarCharts, LineCharts, and AreaCharts. It is used as a return value from method calls that retrieve data from a chart given a location, which is what happens by default when the user left-clicks on a chart data entity.

A CategoryDataItem describes a dataset with one or more series and values associated with categories. The data for these charts will be in the format of:

• BBjString rowKey$
• BBjString colKey$
• Number value!

You can chart multiple categories by specifying unique values for the row keys and column keys. When the data is plotted in a bar chart, for example, the parameters are used as follows:

• rowKey$ -> What is displayed in the chart's legend
• colKey$ -> What is displayed in the chart's domain axis
• value! -> What is displayed in the chart's range axis

So if the dataset consists of 3 CategoryDataItems, all with unique row and column keys, there will be a total of 9 bars drawn on the chart. That is because there are 3 columns, and there will be 3 bars per column - one for each row.
It is also possible to make all row keys the same in a dataset. In this case the sample dataset still consists of 3 CategoryDataItems, but only the column keys are unique. This results in a chart with only 3 bars instead of 9. In this case, since the row keys are all the same, there will be a single item in the chart's legend. Because of this, it is common to hide the legend since it does not provide any additional value. The domain axis will have 3 entries, one for each column key, containing a single bar.