How to pass the curl -F parameter in the httr package? - r

Question

Hi I try to translate this curl instruction using httr
curl -H "Authorization: Token f2210dacd9c6ccb8133606d94ff8e61d99b477fd" -F file=#test.txt -F filename=test.txt -F parent_dir=/ http://cloud.seafile.com:8082/upload-api/73c5d117-3bcf-48a0-aa2a-3f48d5274ae3
Without the -F parameter the instruction is :
httr::POST(
url = "http://cloud.seafile.com:8082/upload-api/73c5d117-3bcf-48a0-aa2a-3f48d5274ae3",
add_headers(Authorization = "Token f2210dacd9c6ccb8133606d94ff8e61d99b477fd")
)
)
I think I have to use the httr::upload_file function but I didn't manage to use this without error.
Do you have any idea how I can do that ?
Regards

Answer 1

Here is how to construct this curl request with httr package. I used httpbin.org to test the request sent.
You'll use POST filling the body with a list. encode argument controls how this list will be handle and by default it is the correct multipart you need.
res <- httr::POST(
url = "http://httpbin.org/post",
httr::add_headers(Authorization = "Token f2210dacd9c6ccb8133606d94ff8e61d99b477fd"),
# Add the file and metadata as body using a list. Default encode is ok
body = list(
file = httr::upload_file("test.txt"),
filename = "test.txt",
parent_dir = "/"
)
)
httr_ouput <- httr::content(res)
One way to check this is ok is to compare output with the curl command you know is working
out <- sys::exec_internal(
'curl -H "Authorization: Token f2210dacd9c6ccb8133606d94ff8e61d99b477fd" -F file=#test.txt -F filename=test.txt -F parent_dir=/ http://httpbin.org/post'
)
curl_output <- jsonlite::fromJSON(rawToChar(out$stdout))
#compare body
identical(curl_output$files, httr_ouput$files)
#> TRUE
identical(curl_output$form, httr_ouput$form)
#> TRUE
You can also do it with the crul package, another wrapper above curl; The logic is identical
con <- crul::HttpClient$new(
url = "http://httpbin.org/post"
)
crul_req <- con$post(
body = list(
file = crul::upload("test.txt"),
filename = "test.ext",
parent_dir = "/"
)
)
crul_output <- jsonlite::fromJSON(crul_req$parse())