Build multipart form data elements. The form_file
function uploads a
file. The form_data
function allows for posting a string or raw vector
with a custom content-type.
form_file(path, type = NULL, name = NULL)form_data(value, type = NULL)
a string with a path to an existing file on disk
MIME content-type of the file.
a string with the file name to use for the upload
a character or raw vector to post