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<h1 class="lined-header"><span>cowboy_req:read_part_body(3)</span></h1>
<div class="sect1">
<h2 id="_name">Name</h2>
<div class="sectionbody">
<div class="paragraph"><p>cowboy_req:read_part_body - Read the current part’s body</p></div>
</div>
</div>
<div class="sect1">
<h2 id="_description">Description</h2>
<div class="sectionbody">
<div class="listingblock">
<div class="content"><!-- Generator: GNU source-highlight 3.1.8
by Lorenzo Bettini
http://www.lorenzobettini.it
http://www.gnu.org/software/src-highlite -->
<pre><tt><span style="font-weight: bold"><span style="color: #000000">read_part_body</span></span>(<span style="color: #009900">Req</span> <span style="color: #990000">::</span> <span style="font-weight: bold"><span style="color: #000000">cowboy_req:req</span></span>())
<span style="color: #990000">-></span> <span style="font-weight: bold"><span style="color: #000000">read_part_body</span></span>(<span style="color: #009900">Req</span>, #{})
<span style="font-weight: bold"><span style="color: #000000">read_part_body</span></span>(<span style="color: #009900">Req</span> <span style="color: #990000">::</span> <span style="font-weight: bold"><span style="color: #000000">cowboy_req:req</span></span>(), <span style="color: #009900">Opts</span>)
<span style="color: #990000">-></span> {<span style="color: #FF6600">ok</span>, <span style="color: #009900">Data</span> <span style="color: #990000">::</span> <span style="font-weight: bold"><span style="color: #000080">binary</span></span>(), <span style="color: #009900">Req</span>}
| {<span style="color: #FF6600">more</span>, <span style="color: #009900">Data</span> <span style="color: #990000">::</span> <span style="font-weight: bold"><span style="color: #000080">binary</span></span>(), <span style="color: #009900">Req</span>}
<span style="color: #009900">Opts</span> <span style="color: #990000">::</span> <span style="font-weight: bold"><span style="color: #000000">cowboy_req:read_body_opts</span></span>()</tt></pre></div></div>
<div class="paragraph"><p>Read the body of the current part of the multipart message.</p></div>
<div class="paragraph"><p>This function reads the request body and parses it as
multipart. Each parts of a multipart representation have
their own headers and body. This function returns the
body of the current part. Examples of multipart media types
are <code>multipart/form-data</code> and <code>multipart/byteranges</code>.</p></div>
<div class="paragraph"><p>This function reads a chunk of the part’s body. A <code>more</code> tuple
is returned when more data remains to be read. Call the function
repeatedly until an <code>ok</code> tuple is returned to read the entire body.</p></div>
<div class="paragraph"><p>Once a part has been read, it can not be read again.</p></div>
<div class="paragraph"><p>Once the body has been read, Cowboy sets the content-length
header if it was not previously provided.</p></div>
</div>
</div>
<div class="sect1">
<h2 id="_arguments">Arguments</h2>
<div class="sectionbody">
<div class="dlist"><dl>
<dt class="hdlist1">
Req
</dt>
<dd>
<p>
The Req object.
</p>
</dd>
<dt class="hdlist1">
Opts
</dt>
<dd>
<p>
A map of body reading options. Please refer to
<a href="../cowboy_req.read_body">cowboy_req:read_body(3)</a>
for details about each option.
</p>
<div class="paragraph"><p>This function uses the same default options as the
<a href="../cowboy_req.read_body">cowboy_req:read_body(3)</a>
function.</p></div>
</dd>
</dl></div>
</div>
</div>
<div class="sect1">
<h2 id="_return_value">Return value</h2>
<div class="sectionbody">
<div class="paragraph"><p>A <code>more</code> tuple is returned when there are more data to be read.</p></div>
<div class="paragraph"><p>An <code>ok</code> tuple is returned when there are no more data to be read.</p></div>
<div class="paragraph"><p>The data is always returned as a binary.</p></div>
<div class="paragraph"><p>The Req object returned in the tuple must be used for that point
onward. It contains a more up to date representation of the request.
For example it may have an added content-length header once the
body has been read.</p></div>
</div>
</div>
<div class="sect1">
<h2 id="_changelog">Changelog</h2>
<div class="sectionbody">
<div class="ulist"><ul>
<li>
<p>
<strong>2.0</strong>: Function introduced. Replaces <code>part_body/1,2</code>.
</p>
</li>
</ul></div>
</div>
</div>
<div class="sect1">
<h2 id="_examples">Examples</h2>
<div class="sectionbody">
<div class="listingblock">
<div class="title">Read a full part’s body</div>
<div class="content"><!-- Generator: GNU source-highlight 3.1.8
by Lorenzo Bettini
http://www.lorenzobettini.it
http://www.gnu.org/software/src-highlite -->
<pre><tt><span style="font-weight: bold"><span style="color: #000000">stream_body</span></span>(<span style="color: #009900">Req0</span>, <span style="color: #009900">Acc</span>) <span style="color: #990000">-></span>
<span style="font-weight: bold"><span style="color: #0000FF">case</span></span> <span style="font-weight: bold"><span style="color: #000000">cowboy_req:read_part_body</span></span>(<span style="color: #009900">Req0</span>) <span style="font-weight: bold"><span style="color: #0000FF">of</span></span>
{<span style="color: #FF6600">more</span>, <span style="color: #009900">Data</span>, <span style="color: #009900">Req</span>} <span style="color: #990000">-></span>
<span style="font-weight: bold"><span style="color: #000000">stream_body</span></span>(<span style="color: #009900">Req</span>, <span style="color: #990000"><<</span> <span style="color: #009900">Acc</span><span style="color: #990000">/</span><span style="font-weight: bold"><span style="color: #000080">binary</span></span>, <span style="color: #009900">Data</span><span style="color: #990000">/</span><span style="font-weight: bold"><span style="color: #000080">binary</span></span> <span style="color: #990000">>></span>);
{<span style="color: #FF6600">ok</span>, <span style="color: #009900">Data</span>, <span style="color: #009900">Req</span>} <span style="color: #990000">-></span>
{<span style="color: #FF6600">ok</span>, <span style="color: #990000"><<</span> <span style="color: #009900">Acc</span><span style="color: #990000">/</span><span style="font-weight: bold"><span style="color: #000080">binary</span></span>, <span style="color: #009900">Data</span><span style="color: #990000">/</span><span style="font-weight: bold"><span style="color: #000080">binary</span></span> <span style="color: #990000">>></span>, <span style="color: #009900">Req</span>}
<span style="font-weight: bold"><span style="color: #0000FF">end</span></span><span style="color: #990000">.</span></tt></pre></div></div>
<div class="listingblock">
<div class="title">Ensure a part’s body is smaller than 64KB</div>
<div class="content"><!-- Generator: GNU source-highlight 3.1.8
by Lorenzo Bettini
http://www.lorenzobettini.it
http://www.gnu.org/software/src-highlite -->
<pre><tt>{<span style="color: #FF6600">ok</span>, <span style="color: #009900">Body</span>, <span style="color: #009900">Req</span>} <span style="color: #990000">=</span> <span style="font-weight: bold"><span style="color: #000000">cowboy_req:read_part_body</span></span>(<span style="color: #009900">Req0</span>, #{<span style="font-weight: bold"><span style="color: #000080">length</span></span> <span style="color: #990000">=></span> <span style="color: #993399">64000</span>})<span style="color: #990000">.</span></tt></pre></div></div>
</div>
</div>
<div class="sect1">
<h2 id="_see_also">See also</h2>
<div class="sectionbody">
<div class="paragraph"><p><a href="../cowboy_req">cowboy_req(3)</a>,
<a href="../cowboy_req.has_body">cowboy_req:has_body(3)</a>,
<a href="../cowboy_req.body_length">cowboy_req:body_length(3)</a>,
<a href="../cowboy_req.read_body">cowboy_req:read_body(3)</a>,
<a href="../cowboy_req.read_urlencoded_body">cowboy_req:read_urlencoded_body(3)</a>,
<a href="../cowboy_req.read_part">cowboy_req:read_part(3)</a></p></div>
</div>
</div>
</div>
<div class="span3 sidecol">
<h3>
Cowboy
2.0
Function Reference
</h3>
<ul>
<li><a href="/docs/en/cowboy/2.0/guide">User Guide</a></li>
<li><a href="/docs/en/cowboy/2.0/manual">Function Reference</a></li>
</ul>
<h4 id="docs-nav">Navigation</h4>
<h4>Version select</h4>
<ul>
<li><a href="/docs/en/cowboy/1.0/manual">1.0</a></li>
<li><a href="/docs/en/cowboy/2.0/manual">2.0</a></li>
</ul>
</div>
</div>
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