handle: Create and configure a curl handle

In curl: A Modern and Flexible Web Client for R

Create and configure a curl handle

Description

Handles are the work horses of libcurl. A handle is used to configure a request with custom options, headers and payload. Once the handle has been set up, it can be passed to any of the download functions such as curl ,curl_download or curl_fetch_memory. The handle will maintain state in between requests, including keep-alive connections, cookies and settings.

Usage

new_handle(...)

handle_setopt(handle, ..., .list = list())

handle_setheaders(handle, ..., .list = list())

handle_getheaders(handle)

handle_getcustom(handle)

handle_setform(handle, ..., .list = list())

handle_reset(handle)

handle_data(handle)

Arguments

...	named options / headers to be set in the handle. To send a file, see form_file. To list all allowed options, see curl_options
handle	Handle to modify
.list	A named list of options. This is useful if you've created a list of options elsewhere, avoiding the use of do.call().

Details

Use new_handle() to create a new clean curl handle that can be configured with custom options and headers. Note that handle_setopt appends or overrides options in the handle, whereas handle_setheaders replaces the entire set of headers with the new ones. The handle_reset function resets only options/headers/forms in the handle. It does not affect active connections, cookies or response data from previous requests. The safest way to perform multiple independent requests is by using a separate handle for each request. There is very little performance overhead in creating handles.

Value

A handle object (external pointer to the underlying curl handle). All functions modify the handle in place but also return the handle so you can create a pipeline of operations.

See Also

Other handles: handle_cookies()

Examples

h <- new_handle()
handle_setopt(h, customrequest = "PUT")
handle_setform(h, a = "1", b = "2")
r <- curl_fetch_memory("https://hb.cran.dev/put", h)
cat(rawToChar(r$content))

# Or use the list form
h <- new_handle()
handle_setopt(h, .list = list(customrequest = "PUT"))
handle_setform(h, .list = list(a = "1", b = "2"))
r <- curl_fetch_memory("https://hb.cran.dev/put", h)
cat(rawToChar(r$content))

curl documentation built on Sept. 30, 2024, 9:35 a.m.