R/group_by_se.R

In seplyr: Improved Standard Evaluation Interfaces for Common Data Manipulation Tasks

#' group_by standard interface.
#'
#' Group a data frame by the groupingVars. group_by_se intentionally groups only by
#' sets of variables, not by expressions over variables.
#'
#' @seealso \code{\link[dplyr]{group_by}}, \code{\link[dplyr]{group_by_at}}
#'
#' @param .data data.frame
#' @param groupingVars character vector of column names to group by.
#' @param add logical, passed to group_by
#' @return .data grouped by columns named in groupingVars
#'
#' @examples
#'
#'
#' datasets::mtcars %.>%
#'   group_by_se(., c("cyl", "gear")) %.>%
#'   head(.)
#'
#' @export
#'
group_by_se <- function(.data, groupingVars, add = FALSE) {
  if(!(is.data.frame(.data) || dplyr::is.tbl(.data))) {
    stop("seplyr::group_by_se first argument must be a data.frame or tbl")
  }
  if(!add) {
    .data <- dplyr::ungroup(.data)
  }
  if(length(groupingVars)>0) {
    if(!is.character(groupingVars)) {
      stop("seplyr::group_by_se groupingVars must be a character vector")
    }
    # convert char vector into spliceable vector
    groupingSyms <- rlang::syms(groupingVars)
    .data <- dplyr::group_by(.data = .data, !!!groupingSyms)
  }
  .data
}