Translate column names or positions into DT column targets

Maps a set of columns onto the zero-based targets indices DataTables expects inside a columnDefs entry. This is what dataFilterServer() uses to honour its hide.columns argument, but it is useful for any hand-rolled DT::datatable() where columns are referred to by name rather than by position – hiding them, setting widths, disabling ordering, and so on.

Usage

resolve_column_targets(data, columns, rownames = FALSE)

Arguments

data

A data frame, or a character vector of the column names in the order they are passed to DT::datatable().

columns

NULL, a character vector of column names, or a numeric vector of one-based column positions to resolve.

rownames

Logical. Whether the table is drawn with a row-names column (the rownames argument of DT::datatable()). When TRUE, row names occupy column 0 and every data column shifts one to the right, so the returned targets are shifted to match. Defaults to FALSE.

Value

An integer vector of zero-based column indices, possibly empty.

Details

Columns that do not exist are dropped with a warning rather than raising an error, so a table fed by a changing data frame keeps rendering when a column comes and goes.

See also

dataFilterServer()

Author

Jared Andrews

Examples

# Hide two columns of a plain DT table by name.
targets <- resolve_column_targets(iris, c("Petal.Length", "Petal.Width"))
targets
#> [1] 2 3

if (interactive()) {
    DT::datatable(
        iris,
        rownames = FALSE,
        options = list(
            columnDefs = list(list(visible = FALSE, targets = targets))
        )
    )
}