Download a file from a REDCap project record — redcap_file_download

This function uses REDCap's API to download a file.

redcap_file_download_oneshot(
  file_name = NULL,
  directory = NULL,
  overwrite = FALSE,
  redcap_uri,
  token,
  record,
  field,
  event = "",
  repeat_instrument = NULL,
  repeat_instance = NULL,
  verbose = TRUE,
  config_options = NULL,
  handle_httr = NULL
)

Arguments

file_name: The name of the file where the downloaded file is saved. If empty the original name of the file will be used and saved in the default directory. Optional.
directory: The directory where the file is saved. By default current directory. Optional
overwrite: Boolean value indicating if existing files should be overwritten. Optional
redcap_uri: The uri/url of the REDCap server typically formatted as "https://server.org/apps/redcap/api/". Required.
token: The user-specific string that serves as the password for a project. Required.
record: The record ID where the file is to be imported. Required
field: The name of the field where the file is saved in REDCap. Required
event: The name of the event where the file is saved in REDCap. Optional
repeat_instrument: The name of the instrument that is repeating for a given event. Optional
repeat_instance: (only for projects with repeating instruments/events) The repeat instance number of the repeating event (if longitudinal) or the repeating instrument (if classic or longitudinal). Default value is '1'. Optional
verbose: A boolean value indicating if messages should be printed to the R console during the operation. Optional.
config_options: A list of options passed to httr::POST(). See details at httr::httr_options(). Optional.
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.

Value

Currently, a list is returned with the following elements,

success: A boolean value indicating if the operation was apparently successful.
status_code: The http status code of the operation.
outcome_message: A human readable string indicating the operation's outcome.
records_affected_count: The number of records inserted or updated.
affected_ids: The subject IDs of the inserted or updated records.
elapsed_seconds: The duration of the function.
raw_text: If an operation is NOT successful, the text returned by REDCap. If an operation is successful, the raw_text is returned as an empty string to save RAM.
file_name: The name of the file persisted to disk. This is useful if the name stored in REDCap is used (which is the default).

Details

Currently, the function doesn't modify any variable types to conform to REDCap's supported variables. See validate_for_write() for a helper function that checks for some common important conflicts.

The function redcap_download_file_oneshot() is soft-deprecated as of REDCapR 1.2.0. Please rename to redcap_file_download_oneshot().

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.

Author

Will Beasley, John J. Aponte

Examples

# \dontrun{
uri     <- "https://bbmc.ouhsc.edu/redcap/api/"
token   <- "D70F9ACD1EDD6F151C6EA78683944E98" # pid=213
record  <- 1
field   <- "mugshot"
# event <- "" # only for longitudinal projects

result_1 <- REDCapR::redcap_file_download_oneshot(
  record        = record,
  field         = field,
  redcap_uri    = uri,
  token         = token
)
#> Preparing to download the file `mugshot-1.jpg`.
#> image/jpeg; name="mugshot-1.jpg" successfully downloaded in 0.1 seconds, and saved as mugshot-1.jpg.
base::unlink("mugshot-1.jpg")

(full_name <- base::tempfile(pattern="mugshot", fileext = ".jpg"))
#> [1] "/var/folders/mm/pltwc2yj1jx192t6dzy9zsrr0000gn/T//RtmpVSAzeS/mugshot8807454e3a7.jpg"
result_2   <- REDCapR::redcap_file_download_oneshot(
  file_name     = full_name,
  record        = record,
  field         = field,
  redcap_uri    = uri,
  token         = token
)
#> Preparing to download the file `/var/folders/mm/pltwc2yj1jx192t6dzy9zsrr0000gn/T//RtmpVSAzeS/mugshot8807454e3a7.jpg`.
#> image/jpeg; name="mugshot-1.jpg" successfully downloaded in 0.1 seconds, and saved as /var/folders/mm/pltwc2yj1jx192t6dzy9zsrr0000gn/T//RtmpVSAzeS/mugshot8807454e3a7.jpg.
base::unlink(full_name)

(relative_name <- "ssss.jpg")
#> [1] "ssss.jpg"
result_3 <- REDCapR::redcap_file_download_oneshot(
  file_name    = relative_name,
  record       = record,
  field        = field,
  redcap_uri   = uri,
  token        = token
)
#> Preparing to download the file `ssss.jpg`.
#> image/jpeg; name="mugshot-1.jpg" successfully downloaded in 0.1 seconds, and saved as ssss.jpg.
base::unlink(relative_name)
# }