R/utils.R

In ardata-fr/dgihesse: Simple 'JavaScript' Interactions in 'shiny' Applications

#' @importFrom shiny observe isolate

# drop NULL items from a list
dropNulls <- function(x) {
  x[!vapply(x, is.null, FUN.VALUE = logical(1))]
}

#' @export
#' @title Factor to character
#' @description Convert factor columns to character in data.frame.
#' @param x data.frame
fact2char <- function(x) {
  i <- sapply(x, is.factor)
  x[i] <- lapply(x[i], as.character)
  x
}

#' @export
#' @title Character to factor
#' @description Convert character columns to factor in data.frame.
#' @param x data.frame
char2fact <- function(x) {
  i <- sapply(x, is.character)
  x[i] <- lapply(x[i], as.factor)
  x
}

cast_to_short_table <- function(x, samp_n = 6, limit = 13, symbol = ".") {
  if (nrow(x) > limit) {
    dat1 <- head(x, n = samp_n)
    dat1[] <- lapply(dat1, format)
    dat2 <- tail(x, n = samp_n)
    dat2[] <- lapply(dat2, format)
    blank_df <- dat1[1, , drop = FALSE]
    blank_df[] <- symbol
    df_info_1 <- paste("Only the", samp_n, "first rows and the", samp_n, "last rows are showned.")
    dat <- rbind(dat1, blank_df, dat2)
  } else {
    dat <- x
    df_info_1 <- ""
  }
  row.names(dat) <- NULL
  attr(dat, "info") <- df_info_1
  dat
}