next
cycles through sort directions. This is used to determine how to
update the sort direction when a header is clicked on.
indicator
and class_
convert the sort direction and precedence of a column from
the sort criteria into a string symbol and a css class respectively in order to
display sort information in the table.
indicator
returns a symbol that is displayed in the header of the corresponding
column, while class_
returns a css class that is assigned to the header element.
The precedence
is always a positive integer (i.e. it starts at 1, not 0).
A column that is not in the sort criteria is assigned an indicator
and class_
of
None
.
Examples of suitable indicators are:
val indicator : t ‑> precedence:int ‑> string option
val class_ : t ‑> precedence:int ‑> string option