columnheader constant
A cell containing header information for a column.
columnheader can be used as a column header in a table or grid. It could also be used in a pie chart to show a similar relationship in the data.
The columnheader establishes a relationship between it and all cells in the corresponding column. It is the structural equivalent to an HTML th element with a column scope.
Authors MUST ensure elements with role columnheader are contained in, or owned by, an element with the role row.
Note: Because cells are organized into rows, there is not a single container element for the column. The column is the set of gridcell elements in a particular position within their respective row containers.
See: developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/Roles/columnheader_role
Implementation
static const String columnheader = 'columnheader';