Checks if an argument is a data frame and (optionally) whether is contains a set of required variables
Usage
assert_data_frame(
arg,
required_vars = NULL,
check_is_grouped = TRUE,
optional = FALSE,
arg_name = rlang::caller_arg(arg),
message = NULL,
class = "assert_data_frame",
call = parent.frame()
)
Arguments
- arg
A function argument to be checked
- required_vars
A list of variables created using
exprs()
- check_is_grouped
Throw an error is
dataset
is grouped? Defaults toTRUE
.- optional
Is the checked argument optional? If set to
FALSE
andarg
isNULL
then an error is thrown- arg_name
string indicating the label/symbol of the object being checked.
- message
string passed to
cli::cli_abort(message)
. WhenNULL
, default messaging is used (see examples for default messages)."{arg_name}"
can be used in messaging.- class
Subclass of the condition.
- call
The execution environment of a currently running function, e.g.
call = caller_env()
. The corresponding function call is retrieved and mentioned in error messages as the source of the error.You only need to supply
call
when throwing a condition from a helper function which wouldn't be relevant to mention in the message.Can also be
NULL
or a defused function call to respectively not display any call or hard-code a code to display.For more information about error calls, see Including function calls in error messages.
Value
The function throws an error if arg
is not a data frame or if arg
is a
data frame but misses any variable specified in required_vars
. Otherwise,
the input is returned invisibly.
See also
Checks for valid input and returns warning or errors messages:
assert_atomic_vector()
,
assert_character_scalar()
,
assert_character_vector()
,
assert_date_vector()
,
assert_expr()
,
assert_expr_list()
,
assert_filter_cond()
,
assert_function()
,
assert_integer_scalar()
,
assert_list_element()
,
assert_list_of()
,
assert_logical_scalar()
,
assert_named()
,
assert_numeric_vector()
,
assert_one_to_one()
,
assert_param_does_not_exist()
,
assert_s3_class()
,
assert_same_type()
,
assert_symbol()
,
assert_unit()
,
assert_vars()
,
assert_varval_list()
Examples
library(dplyr)
library(rlang)
dm <- tribble(
~STUDYID, ~USUBJID,
"XYZ", "1",
"XYZ", "2"
)
example_fun <- function(dataset) {
assert_data_frame(dataset, required_vars = exprs(STUDYID, USUBJID))
}
example_fun(dm)
try(example_fun(select(dm, -STUDYID)))
#> Error in example_fun(select(dm, -STUDYID)) :
#> Required variable `STUDYID` is missing in `dataset`
try(example_fun("Not a dataset"))
#> Error in example_fun("Not a dataset") :
#> Argument `dataset` must be class <data.frame>, but is a string.
try(example_fun(group_by(dm, USUBJID)))
#> Error in example_fun(group_by(dm, USUBJID)) :
#> Argument `dataset` must not be a grouped dataset, please `ungroup()` it.