ncurl_session {nanonext} | R Documentation |
ncurl Session
Description
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.
Usage
ncurl_session(
url,
convert = TRUE,
method = NULL,
headers = NULL,
data = NULL,
response = NULL,
timeout = NULL,
tls = NULL
)
transact(session)
Arguments
url |
the URL address. |
convert |
[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. |
method |
(optional) the HTTP method (defaults to 'GET' if not specified). |
headers |
(optional) a named character vector specifying the HTTP
request headers, for example: |
data |
(optional) character request data to be submitted. |
response |
(optional) a character vector specifying the response headers
to return e.g. |
timeout |
(optional) integer value in milliseconds after which the connection and subsequent transact attempts time out. |
tls |
(optional) applicable to secure HTTPS sites only, a client TLS
Configuration object created by |
session |
an 'ncurlSession' object. |
Value
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). Usestatus_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 usingwriteBin
.
See Also
ncurl_aio
for asynchronous http requests.
Examples
s <- ncurl_session("https://www.r-project.org/", response = "date", timeout = 2000L)
s
if (!is_error_value(s)) transact(s)
if (!is_error_value(s)) close(s)