R/rescue_attributes.R

In codebook: Automatic Codebooks from Metadata Encoded in Dataset Attributes

#' Rescue lost attributes
#'
#' You can use this function if some of your items have lost their attributes during wrangling
#' Variables have to have the same name (Duh) and no attributes should be overwritten.
#' But use with care. Similar to [labelled::copy_labels()].
#'
#'
#' @param df_no_attributes the data frame with missing attributes
#' @param df_with_attributes the data frame from which you want to restore attributes
#'
#' @export
#'
rescue_attributes <- function(df_no_attributes, df_with_attributes) {
  for (i in seq_along(names(df_no_attributes))) {
    var <- names(df_no_attributes)[i]
    if (var %in% names(df_with_attributes) &&
        is.null(attributes(df_no_attributes[[var]]))) {
      attributes(df_no_attributes[[var]]) <-
        attributes(df_with_attributes[[var]])
    } else {
      for (e in seq_along(names(attributes(df_with_attributes[[var]])))) {
        attrib_name <- names(attributes(df_with_attributes[[var]]))[e]
        if (!attrib_name %in% names(attributes(df_no_attributes[[var]]))) {
          attributes(df_no_attributes[[var]])[[attrib_name]] <-
            attributes(df_with_attributes[[var]])[[attrib_name]]
        }
      }
    }
  }
  df_no_attributes
}