= nng_http_handler_set_data(3)
//
// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
// Copyright 2018 Capitar IT Group BV <info@capitar.com>
//
// This document is supplied under the terms of the MIT License, a
// copy of which should be located in the distribution where this
// file was obtained (LICENSE.txt).  A copy of the license may also be
// found online at https://opensource.org/licenses/MIT.
//

== NAME

nng_http_handler_get_data - set extra data for HTTP handler

== SYNOPSIS

[source, c]
-----------
#include <nng/nng.h>
#include <nng/supplemental/http/http.h>

void *nng_http_handler_get_data(nng_http_handler *handler, void *data,
    void (*dtor)(void *));
-----------

== DESCRIPTION

The `nng_http_handler_set_data()` function is used to set an additional
_data_ for the _handler_.  The stored _data_ can be retrieved later
in the handler function using
<<nng_http_handler_get_data#,nng_http_handler_get_data(3)>>.

Additionally, when the handler is deallocated, if _dtor_ is not `NULL`,
then it will be called with _data_ as its argument.  The intended use of
this function is deallocate any resources associated with _data_.

== RETURN VALUES

This function returns 0 on success, and non-zero otherwise.

== ERRORS

`NNG_ENOMEM`:: Insufficient free memory to perform the operation.
`NNG_ENOTSUP`:: No support for HTTP in the library.

== SEE ALSO

<<nng_http_handler_alloc#,nng_http_handler_alloc(3)>>,
<<nng_http_handler_get_data#,nng_http_server_get_data(3)>>,
<<nng_http_server_add_handler#,nng_http_server_add_handler(3)>>,
<<nng#,nng(7)>>