R/redcap-dag-read.R

In OuhscBbmc/REDCapR: Interaction Between R and REDCap

#' @title
#' Read data access groups from a REDCap project
#'
#' @description
#' This function reads all available data access groups from
#' REDCap an returns them as a [tibble::tibble()].
#'
#' @param redcap_uri The
#' [uri](https://en.wikipedia.org/wiki/Uniform_Resource_Identifier)/url
#' of the REDCap server
#' typically formatted as "https://server.org/apps/redcap/api/".
#' Required.
#' @param token The user-specific string that serves as the password for a
#' project.  Required.
#' @param http_response_encoding  The encoding value passed to
#' [httr::content()].  Defaults to 'UTF-8'.
#' @param locale a [readr::locale()] object to specify preferences like
#' number, date, and time formats.  This object is passed to
#' [readr::read_csv()].  Defaults to [readr::default_locale()].
#' @param verbose A boolean value indicating if `message`s should be printed
#' to the R console during the operation.  The verbose output might contain
#' sensitive information (*e.g.* PHI), so turn this off if the output might
#' be visible somewhere public. Optional.
#' @param config_options A list of options passed to [httr::POST()].
#' See details at [httr::httr_options()]. Optional.
#' @param handle_httr The value passed to the `handle` parameter of
#' [httr::POST()].
#' This is useful for only unconventional authentication approaches.  It
#' should be `NULL` for most institutions.  Optional.
#'
#' @return
#' Currently, a list is returned with the following elements:
#' * `data`: A [tibble::tibble()] of all data access groups of the project.
#' * `success`: A boolean value indicating if the operation was apparently
#' successful.
#' * `status_codes`: A collection of
#' [http status codes](https://en.wikipedia.org/wiki/List_of_HTTP_status_codes),
#' separated by semicolons.  There is one code for each batch attempted.
#' * `outcome_messages`: A collection of human readable strings indicating the
#' operations' semicolons.  There is one code for each batch attempted.  In an
#' unsuccessful operation, it should contain diagnostic information.
#' * `elapsed_seconds`: The duration of the function.
#'
#' @author
#' Jonathan M. Mang
#'
#' @references
#' The official documentation can be found on the 'API Help Page'
#' and 'API Examples' pages on the REDCap wiki (*i.e.*,
#' https://community.projectredcap.org/articles/456/api-documentation.html
#' and
#' https://community.projectredcap.org/articles/462/api-examples.html).
#' If you do not have an account for the wiki, please ask your campus REDCap
#' administrator to send you the static material.
#'
#' @examples
#' \dontrun{
#' uri     <- "https://bbmc.ouhsc.edu/redcap/api/"
#' token   <- "9A81268476645C4E5F03428B8AC3AA7B"
#' REDCapR::redcap_dag_read(redcap_uri=uri, token=token)$data
#' }

#' @export
redcap_dag_read <- function(
  redcap_uri,
  token,
  http_response_encoding        = "UTF-8",
  locale                        = readr::default_locale(),
  verbose                       = TRUE,
  config_options                = NULL,
  handle_httr                   = NULL
) {

  checkmate::assert_character(redcap_uri                , any.missing=FALSE,     len=1, pattern="^.{1,}$")
  checkmate::assert_character(token                     , any.missing=FALSE,     len=1, pattern="^.{1,}$")
  checkmate::assert_character(http_response_encoding    , any.missing=FALSE,     len=1)
  checkmate::assert_class(    locale, "locale"          , null.ok = FALSE)

  checkmate::assert_logical(  verbose                   , any.missing=FALSE,     len=1, null.ok=TRUE)
  checkmate::assert_list(     config_options            , any.missing=TRUE ,            null.ok=TRUE)

  token               <- sanitize_token(token)
  verbose             <- verbose_prepare(verbose)

  post_body <- list(
    token                   = token,
    content                 = "dag",
    format                  = "csv"
  )

  # This is the important call that communicates with the REDCap server.
  kernel <-
    kernel_api(
      redcap_uri      = redcap_uri,
      post_body       = post_body,
      encoding        = http_response_encoding,
      config_options  = config_options,
      handle_httr     = handle_httr
    )

  if (kernel$success) {
    try(
      # Convert the raw text to a dataset.
      ds <-
        readr::read_csv(
          file            = I(kernel$raw_text),
          locale          = locale,
          show_col_types  = FALSE
        ),

      # Don't print the warning in the try block.  Print it below,
      #   where it's under the control of the caller.
      silent = TRUE
    )

    if (exists("ds") && inherits(ds, "data.frame")) {
      outcome_message <- sprintf(
        "%s data access groups were read from REDCap in %0.1f seconds.  The http status code was %i.",
        format(nrow(ds), big.mark = ",", scientific = FALSE, trim = TRUE),
        kernel$elapsed_seconds,
        kernel$status_code
      )

      # If an operation is successful, the `raw_text` is no longer returned to
      #   save RAM.  The content is not really necessary with httr's status
      #   message exposed.
      kernel$raw_text   <- ""
    } else { # ds doesn't exist as a data.frame.
      # nocov start
      # Override the 'success' determination from the http status code.
      #   and return an empty data.frame.
      kernel$success   <- FALSE
      ds               <- tibble::tibble()
      outcome_message  <- sprintf(
        "The REDCap dag read failed.  The http status code was %i.  The 'raw_text' returned was '%s'.",
        kernel$status_code,
        kernel$raw_text
      )
      # nocov end
    }
  } else { # kernel fails
    # nocov start
    ds              <- tibble::tibble() # Return an empty data.frame
    outcome_message <-
      if (any(grepl(kernel$regex_empty, kernel$raw_text))) {
        "The REDCapR read/export operation was not successful.  The returned dataset was empty."  # nocov
      } else {
        sprintf(
          "The REDCapR read/export operation was not successful.  The error message was:\n%s",
          kernel$raw_text
        )
      }
    # nocov end
  }

  if (verbose)
    message(outcome_message)

  list(
    data               = ds,
    success            = kernel$success,
    status_code        = kernel$status_code,
    outcome_message    = outcome_message,
    elapsed_seconds    = kernel$elapsed_seconds,
    raw_text           = kernel$raw_text
  )
}