parameterize encoding and handle passed to httr::POST()

@brandonpotvin, glad the last one worked.  Love to be wrong.
 Will you give this commit a shot?  Notice I renamed to `handle_httr` and also added `encode_httr` that you should set to "form".

ref #429

Author: wibeasley

R/kernel-api.R

@@ -16,6 +16,14 @@
 #' to 'UTF-8'.
 #' @param content_type The MIME value passed to [httr::content()].  Defaults
 #' to 'text/csv'.
+#' @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.
+#' @param encode_httr The value passed to the `encode` parameter of
+#' [httr::POST()].
+#' This is useful for only unconventional authentication approaches.
+#' Defaults to `"multipart"`, which is appropriate for most institutions.
 #'
 #' @return
 #' A [utils::packageVersion].
@@ -50,12 +58,14 @@ kernel_api <- function(
   config_options,
   encoding            = "UTF-8",
   content_type        = "text/csv",
-  cdc_handle          = NULL
-  ) {
+  handle_httr         = NULL,
+  encode_httr         = "multipart"
+) {
 
   checkmate::assert_character(redcap_uri    , len = 1, any.missing = FALSE, null.ok = FALSE)
   checkmate::assert_character(encoding      , len = 1, any.missing = FALSE, null.ok = FALSE)
   checkmate::assert_character(content_type  , len = 1, any.missing = FALSE, null.ok = FALSE)
+  checkmate::assert_character(encode_httr   , len = 1, any.missing = FALSE, null.ok = FALSE)
 
   start_time <- Sys.time()
 
@@ -67,8 +77,8 @@ kernel_api <- function(
     url     = redcap_uri,
     body    = post_body,
     config  = config_options,
-    handle  = cdc_handle,
-    encode  = "form",
+    handle  = handle_httr,
+    encode  = encode_httr,
     httr::user_agent("OuhscBbmc/REDCapR")
   )
 

R/redcap-read-oneshot.R

@@ -85,6 +85,14 @@
 #' 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.
+#' @param encode_httr The value passed to the `encode` parameter of
+#' [httr::POST()].
+#' This is useful for only unconventional authentication approaches.
+#' Defaults to `"multipart"`, which is appropriate for most institutions.
 #'
 #' @return
 #' Currently, a list is returned with the following elements:
@@ -195,7 +203,8 @@ redcap_read_oneshot <- function(
   locale                        = readr::default_locale(),
   verbose                       = TRUE,
   config_options                = NULL,
-  cdc_handle                    = NULL
+  handle_httr                   = NULL,
+  encode_httr                   = "multipart"
 ) {
 
   checkmate::assert_character(redcap_uri                , any.missing=FALSE, len=1, pattern="^.{1,}$")
@@ -228,6 +237,7 @@ redcap_read_oneshot <- function(
   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)
+  checkmate::assert_character(encode_httr               , any.missing=FALSE, len=1, null.ok = FALSE)
 
   validate_field_names(fields, stop_on_error = TRUE)
 
@@ -273,7 +283,8 @@ redcap_read_oneshot <- function(
     post_body       = post_body,
     config_options  = config_options,
     encoding        = http_response_encoding,
-    cdc_handle      = cdc_handle
+    handle_httr     = handle_httr,
+    encode_httr     = encode_httr
   )
 
   if (kernel$success) {