#' Validates and Reports If Formatted Like Regex Provided
#'
#' Validates and Reports If Formatted Like Regex Provided
#'
#' @param data A data frame.
#' @param x Column name from \code{data} (character string).
#' @param regex the regular expression to be tested against.
#' @param \dots ignored.
#' @export
#' @examples
#' dat <- data.frame(
#' vals = c('Greg', 'John', 'Tyrone', 'Susan', 'Kyra', 'Nells12', NA, ""),
#' stringsAsFactors = FALSE
#' )
#' vc_regex(dat, 'vals', '^[A-Z][^0-9]+$')
#' vc_regex(dat, 'vals', '^[A-Z].+$')
vc_regex <- function(data, x, regex, ...){
## select the column & replace missing with NA
col <- sub_out_missing(data[[x]])
## record missing (NA)
is_na <- is.na(col)
## expression to validate against (elementwise)
is_valid <- stringi::stri_detect_regex(col, regex)
is_valid[is_na] <- NA
## valid columnwise: Are all elelemnts either valid or NA?
are_valid <- all(is_valid|is_na)
## generate the comment
if (!are_valid){
message <- sprintf(
"The following rows of %s do not follow the format (%s) provided:\n\n%s\n\n\n\n",
sQuote(x),
regex,
output_truncate(which(!(is_valid|is_na)))
)
} else {
message <- NULL
}
## construct vc list & class
vc_output <- list(
column_name = x,
valid = are_valid,
message = message,
passing = is_valid,
missing = is_na,
call = 'vc_regex'
)
class(vc_output) <- 'vc'
vc_output
}
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.