nano cURL - a minimalist http(s) client. A session encapsulates a connection,
along with all related parameters, and may be used to return data multiple
times by repeatedly calling transact
, which transacts once over the
connection.
ncurl_session(
url,
convert = TRUE,
method = NULL,
headers = NULL,
data = NULL,
response = NULL,
timeout = NULL,
tls = NULL
)transact(session)
For ncurl_session
: an 'ncurlSession' object if successful, or
else an 'errorValue'.
For transact
: a named list of 3 elements:
$status
- integer HTTP repsonse status code (200 - OK).
Use status_code
for a translation of the meaning.
$headers
- named list of response headers (if specified in
the session), or NULL otherwise. If the status code is within the 300
range, i.e. a redirect, the response header 'Location' is automatically
appended to return the redirect address.
$data
- the response body as a character string (if
'convert = TRUE' was specified for the session), which may be further
parsed as html, json, xml etc. as required, or else a raw byte vector,
which may be saved as a file using writeBin
.
the URL address.
[default TRUE] logical value whether to attempt conversion of the received raw bytes to a character vector. Set to FALSE if downloading non-text data.
(optional) the HTTP method as a character string. Defaults to 'GET' if not specified, and could also be 'POST', 'PUT' etc.
(optional) a named character vector specifying the HTTP
request headers, for example:
c(Authorization = "Bearer APIKEY", `Content-Type` = "text/plain")
A non-character or non-named vector will be ignored.
(optional) character string request data to be submitted. If a vector, only the first element is taken, and non-character objects are ignored.
(optional) a character vector specifying the response headers
to return e.g. c("date", "server")
. These are case-insensitive and
will return NULL if not present. A non-character vector will be ignored.
(optional) integer value in milliseconds after which the connection and subsequent transact attempts time out.
(optional) applicable to secure HTTPS sites only, a client TLS
Configuration object created by tls_config
. If missing or
NULL, certificates are not validated.
an 'ncurlSession' object.
ncurl_aio
for asynchronous http requests.
s <- ncurl_session("https://postman-echo.com/get",
response = "date",
timeout = 2000L)
s
if (is_ncurl_session(s)) transact(s)
if (is_ncurl_session(s)) close(s)
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