fileUpload function

Specify information about a file to upload in an HTTP request

This function creates an object that describes all of the details needed to include the contents of a file in the submission of an HTTP request, typically a multi-part form submitted via postForm. The idea is that we want to transfer the contents of a file or a buffer of data within R that is not actually stored on the file system but is resident in the R session. We want to be able to specify either the name of the file and have RCurl read the contents when they are needed, or alternatively specify the contents ourselves if it makes sense that we already have the contents in R, e.g. that they are dynamically generated. Additionally, we may need to specify the type of data in the file/buffer via the Content-Type field for this parameter in the request. This function allows us to specify either the file name or contents and optionally the content type.

This is used as an element in of the params argument postForm and the native C code understands and processes objects returned from this function.

fileUpload(filename = character(), contents = character(), contentType = character())

Arguments

• filename: the name of the file that RCurl is to pass in the form submission/HTTP request. If this is specified and no value for contents is given, this has to identify a valid/existing file. If contents is specified, any value provided here is used simply to provide information about the provenance of the data in contents. The file need not exist. The path is expanded by the function, so ~ can be used.
• contents: either a character vector or a raw vector giving the contents or data to be submitted. If this is provided, filename is not needed and not read.
• contentType: a character string (vector of length 1) giving the type of the content, e.g. text/plain, text/html, which helps the server receiving the data to interpret the contents. If omitted, this is omitted from the form submission and the recipient left to guess.

Returns

An object of (S3) class FileUploadInfo with fields filename, contents and contentType.

References

https://curl.se/

Author(s)

Duncan Temple Lang

See Also

postForm