ctl_new_pillar {pillar} | R Documentation |
Customize the appearance of simple pillars in your tibble subclass
Description
Gain full control over the appearance of the pillars of your tibble subclass
in its body.
This method is intended for implementers of subclasses of the "tbl"
class.
Users will rarely need them.
Usage
ctl_new_pillar(controller, x, width, ..., title = NULL)
ctl_new_rowid_pillar(controller, x, width, ..., title = NULL, type = NULL)
Arguments
controller |
The object of class |
x |
A simple (one-dimensional) vector. |
width |
The available width, can be a vector for multiple tiers. |
... |
These dots are for future extensions and must be empty. |
title |
The title, derived from the name of the column in the data. |
type |
String for specifying a row ID type. Current values in use are
|
Details
ctl_new_pillar()
is called to construct pillars for regular (one-dimensional)
vectors.
The default implementation returns an object constructed with pillar()
.
Extend this method to modify the pillar components returned from the default
implementation.
Override this method to completely change the appearance of the pillars.
Components are created with new_pillar_component()
or pillar_component()
.
In order to customize printing of row IDs, a method can be supplied for the
ctl_new_rowid_pillar()
generic.
All components must be of the same height. This restriction may be levied in the future.
Implementations should return NULL
if none of the data
fits the available width.
See Also
See ctl_new_pillar_list()
for creating pillar objects for compound columns:
packed data frames, matrices, or arrays.
Examples
# Create pillar objects
ctl_new_pillar(
palmerpenguins::penguins,
palmerpenguins::penguins$species[1:3],
width = 60
)
ctl_new_pillar(
palmerpenguins::penguins,
palmerpenguins::penguins$bill_length_mm[1:3],
width = 60
)
# Customize output
lines <- function(char = "-") {
stopifnot(nchar(char) == 1)
structure(char, class = "lines")
}
format.lines <- function(x, width, ...) {
paste(rep(x, width), collapse = "")
}
ctl_new_pillar.line_tbl <- function(controller, x, width, ...) {
out <- NextMethod()
new_pillar(list(
title = out$title,
type = out$type,
lines = new_pillar_component(list(lines("=")), width = 1),
data = out$data
))
}
ctl_new_rowid_pillar.line_tbl <- function(controller, x, width, ...) {
out <- NextMethod()
new_pillar(
list(
title = out$title,
type = out$type,
lines = new_pillar_component(list(lines("=")), width = 1),
data = out$data
),
width = as.integer(floor(log10(max(nrow(x), 1))) + 1)
)
}
vctrs::new_data_frame(
list(a = 1:3, b = letters[1:3]),
class = c("line_tbl", "tbl")
)
ctl_new_rowid_pillar.roman_tbl <- function(controller, x, width, ...) {
out <- NextMethod()
rowid <- utils::as.roman(seq_len(nrow(x)))
width <- max(nchar(as.character(rowid)))
new_pillar(
list(
title = out$title,
type = out$type,
data = pillar_component(
new_pillar_shaft(list(row_ids = rowid),
width = width,
class = "pillar_rif_shaft"
)
)
),
width = width
)
}
vctrs::new_data_frame(
list(a = 1:3, b = letters[1:3]),
class = c("roman_tbl", "tbl")
)