log in to the LISS Data Archive — liss

authenticates with username and password (retrieved from the system keyring via keyring::key_get()) and handles two-factor verification. stores the authenticated session in an internal cache for use by all other liss_* functions.

Usage

liss_login(username = NULL)

Arguments

username: character or numeric. the LISS archive username (typically a 5-digit number). if NULL (the default), looks up saved credentials via keyring::key_list(). when exactly one set of credentials is stored, that username is used automatically. if no credentials are saved, prompts interactively for username and password.

Value

the authenticated rvest::session (invisibly), or NULL on failure.

Examples

if (FALSE) { # \dontrun{
# store credentials once (interactive prompt)
liss_store_credentials(username = 12345)

# then log in — credentials are picked up automatically
liss_login()
} # }