Sippet.Message.get_and_update_header_back
You're seeing just the function
get_and_update_header_back
, go back to Sippet.Message module for more information.
Specs
get_and_update_header_back( t(), header(), (multiple_value() -> {get, multiple_value()} | :pop) ) :: {get, t()} when get: multiple_value()
Gets the last value from header
and updates it, all in one pass.
fun
is called with the current last value under header
in message
(or
nil
if key
is not present in message
) and must return a two-element
tuple: the "get" value (the retrieved value, which can be operated on before
being returned) and the new value to be stored under header
in the
resulting new message. fun
may also return :pop
, which means the current
value shall be removed from message
and returned (making this function
behave like Sippet.Message.pop_header_back(message, header)
. The returned
value is a tuple with the "get" value returned by fun
and a new message
with the updated values under header
.