= nng_http_handler_collect_body(3http)
//
// 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_collect_body - set HTTP handler to collect request body

== SYNOPSIS

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

int nng_http_handler_collect_body(nng_http_handler *handler, bool want, size_t maxsz);
----

== DESCRIPTION

The `nng_http_handler_collect_data()` function causes the _handler_ to
collect any request body that was submitted with the request, and attach
it to the `nng_http_req` before the handler is called.

Subsequently the data can be retrieved by the handler from the request with the
xref:nng_http_req_get_data.3http.adoc[`nng_http_req_get_data()`] function.

The collection is enabled if _want_ is true.
Furthermore, the data that the client may sent is limited by the
value of _maxsz_.
If the client attempts to send more data than _maxsz_, then the
request will be terminated with a 400 "`Bad Request`" status.

TIP: Limiting the size of incoming request data can provide protection
against denial of service attacks, as a buffer of the client-supplied
size must be allocated to receive the data.

In order to provide an unlimited size, use `(size_t)-1` for _maxsz_.
The value `0` for _maxsz_ can be used to prevent any data from being passed
by the client.

The built-in handlers for files, directories, and static data limit the
_maxsz_ to zero by default.
Otherwise the default setting is to enable this capability with a default
value of _maxsz_ of 1 megabyte.

NOTE: The handler looks for data indicated by the `Content-Length:` HTTP
header.
If this header is absent, the request is assumed not to contain any data.

NOTE: This specifically does not support the `Chunked` transfer-encoding.
This is considered a bug, and is a deficiency for full HTTP/1.1 compliance.
However, few clients send data in this format, so in practice this should
create few limitations.

== RETURN VALUES

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

== ERRORS

[horizontal]
`NNG_ENOTSUP`:: No support for HTTP in the library.

== SEE ALSO

[.text-left]
xref:nng_http_handler_alloc.3http.adoc[nng_http_handler_alloc(3http)],
xref:nng_http_server_add_handler.3http.adoc[nng_http_server_add_handler(3http)],
xref:nng_http_req_get_data.3http.adoc[nng_http_req_get_data(3http)],
xref:nng.7.adoc[nng(7)]