R/local-proxy.R

In lifecycle-project/ds-cs-functions: Helper Functions for Use with 'DataSHIELD'

#' Generate a local proxy dataframe to enable local auto-completion in RStudio
#'
#' If you have a remote dataframe on the servers, it can be challenging to
#' remember variable names when writing code. Because the dataframes are on
#' remote servers, auto-complete won't work in RStudio. The purpose of this
#' function is to create a local object that has the same structure as the
#' remote data frame and enables the use of autocomplete when writing DataSHIELD
#' code.
#'
#' If you have a dataframe "D" with columns LAB_TSC, DIS_CVA and
#' DIS_DIAB, normally you would need to write:
#'
#' `ds.summary("D$LAB_TSC")` with the variable name spelled correctly
#' (no autocomplete!) and remember quotation marks. However after running this
#' function you can type:
#'
#' `ds.summary(D$` and hit tab, and the list of variables will be displayed.
#' Choose one and hit enter to finish up with:
#'
#' `ds.summary(D$LAB_TSC)` - no quotation marks needed either!
#'
#' @template conns
#' @template df
#' @template checks
#'
#' @return Creates a local proxy dataframe. Stops function if `df` doesn't exist
#' or contains variables with inconsistent class across cohorts.
#'
#' @importFrom DSI datashield.connections_find
#'
#' @export
dh.localProxy <- function(df = NULL, conns = NULL, checks = TRUE) {
  if (is.null(df)) {
    stop("`df` must not be NULL.", call. = FALSE)
  }

  if (checks == TRUE) {
    .isDefined(df = df, conns = conns)
  }

  if (is.null(conns)) {
    conns <- datashield.connections_find()
  }

  discrep <- dh.classDiscrepancy(conns = conns, df = df, checks = FALSE)
  if (any(discrep$discrepancy == "yes")) {
    warning("All columns not found in all cohorts, please see tibble returned and correct this", call. = FALSE)
    return(discrep)
  }

  tempDF <- data.frame(matrix(paste0("D$", discrep$variable), ncol = length(discrep$variable), nrow = 1))
  colnames(tempDF) <- discrep$variable
  assign(df, tempDF, envir = parent.frame())
}