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<div class="yui-g" id="topics-http-file-uploads">
<div class="section" id="s-file-uploads">
<span id="file-uploads"></span><h1>File Uploads<a class="headerlink" href="#file-uploads" title="Permalink to this headline">¶</a></h1>
<div class="versionadded">
<span class="title">New in Django 1.0:</span> <a class="reference internal" href="../../releases/1.0.html"><em>Please, see the release notes</em></a></div>
<p>When Django handles a file upload, the file data ends up placed in
<a class="reference internal" href="../../ref/request-response.html#django.http.HttpRequest.FILES" title="django.http.HttpRequest.FILES"><tt class="xref py py-attr docutils literal"><span class="pre">request.FILES</span></tt></a> (for more on the
<tt class="docutils literal"><span class="pre">request</span></tt> object see the documentation for <a class="reference internal" href="../../ref/request-response.html"><em>request and response objects</em></a>). This document explains how files are stored on disk
and in memory, and how to customize the default behavior.</p>
<div class="section" id="s-basic-file-uploads">
<span id="basic-file-uploads"></span><h2>Basic file uploads<a class="headerlink" href="#basic-file-uploads" title="Permalink to this headline">¶</a></h2>
<p>Consider a simple form containing a <a class="reference internal" href="../../ref/forms/fields.html#django.forms.FileField" title="django.forms.FileField"><tt class="xref py py-class docutils literal"><span class="pre">FileField</span></tt></a>:</p>
<div class="highlight-python"><div class="highlight"><pre><span class="kn">from</span> <span class="nn">django</span> <span class="kn">import</span> <span class="n">forms</span>
<span class="k">class</span> <span class="nc">UploadFileForm</span><span class="p">(</span><span class="n">forms</span><span class="o">.</span><span class="n">Form</span><span class="p">):</span>
<span class="n">title</span> <span class="o">=</span> <span class="n">forms</span><span class="o">.</span><span class="n">CharField</span><span class="p">(</span><span class="n">max_length</span><span class="o">=</span><span class="mi">50</span><span class="p">)</span>
<span class="nb">file</span> <span class="o">=</span> <span class="n">forms</span><span class="o">.</span><span class="n">FileField</span><span class="p">()</span>
</pre></div>
</div>
<p>A view handling this form will receive the file data in
<a class="reference internal" href="../../ref/request-response.html#django.http.HttpRequest.FILES" title="django.http.HttpRequest.FILES"><tt class="xref py py-attr docutils literal"><span class="pre">request.FILES</span></tt></a>, which is a dictionary
containing a key for each <a class="reference internal" href="../../ref/forms/fields.html#django.forms.FileField" title="django.forms.FileField"><tt class="xref py py-class docutils literal"><span class="pre">FileField</span></tt></a> (or
<a class="reference internal" href="../../ref/forms/fields.html#django.forms.ImageField" title="django.forms.ImageField"><tt class="xref py py-class docutils literal"><span class="pre">ImageField</span></tt></a>, or other <a class="reference internal" href="../../ref/forms/fields.html#django.forms.FileField" title="django.forms.FileField"><tt class="xref py py-class docutils literal"><span class="pre">FileField</span></tt></a>
subclass) in the form. So the data from the above form would
be accessible as <tt class="docutils literal"><span class="pre">request.FILES['file']</span></tt>.</p>
<p>Note that <a class="reference internal" href="../../ref/request-response.html#django.http.HttpRequest.FILES" title="django.http.HttpRequest.FILES"><tt class="xref py py-attr docutils literal"><span class="pre">request.FILES</span></tt></a> will only
contain data if the request method was <tt class="docutils literal"><span class="pre">POST</span></tt> and the <tt class="docutils literal"><span class="pre"><form></span></tt> that posted
the request has the attribute <tt class="docutils literal"><span class="pre">enctype="multipart/form-data"</span></tt>. Otherwise,
<tt class="docutils literal"><span class="pre">request.FILES</span></tt> will be empty.</p>
<p>Most of the time, you'll simply pass the file data from <tt class="docutils literal"><span class="pre">request</span></tt> into the
form as described in <a class="reference internal" href="../../ref/forms/api.html#binding-uploaded-files"><em>Binding uploaded files to a form</em></a>. This would look
something like:</p>
<div class="highlight-python"><div class="highlight"><pre><span class="kn">from</span> <span class="nn">django.http</span> <span class="kn">import</span> <span class="n">HttpResponseRedirect</span>
<span class="kn">from</span> <span class="nn">django.shortcuts</span> <span class="kn">import</span> <span class="n">render_to_response</span>
<span class="c"># Imaginary function to handle an uploaded file.</span>
<span class="kn">from</span> <span class="nn">somewhere</span> <span class="kn">import</span> <span class="n">handle_uploaded_file</span>
<span class="k">def</span> <span class="nf">upload_file</span><span class="p">(</span><span class="n">request</span><span class="p">):</span>
<span class="k">if</span> <span class="n">request</span><span class="o">.</span><span class="n">method</span> <span class="o">==</span> <span class="s">'POST'</span><span class="p">:</span>
<span class="n">form</span> <span class="o">=</span> <span class="n">UploadFileForm</span><span class="p">(</span><span class="n">request</span><span class="o">.</span><span class="n">POST</span><span class="p">,</span> <span class="n">request</span><span class="o">.</span><span class="n">FILES</span><span class="p">)</span>
<span class="k">if</span> <span class="n">form</span><span class="o">.</span><span class="n">is_valid</span><span class="p">():</span>
<span class="n">handle_uploaded_file</span><span class="p">(</span><span class="n">request</span><span class="o">.</span><span class="n">FILES</span><span class="p">[</span><span class="s">'file'</span><span class="p">])</span>
<span class="k">return</span> <span class="n">HttpResponseRedirect</span><span class="p">(</span><span class="s">'/success/url/'</span><span class="p">)</span>
<span class="k">else</span><span class="p">:</span>
<span class="n">form</span> <span class="o">=</span> <span class="n">UploadFileForm</span><span class="p">()</span>
<span class="k">return</span> <span class="n">render_to_response</span><span class="p">(</span><span class="s">'upload.html'</span><span class="p">,</span> <span class="p">{</span><span class="s">'form'</span><span class="p">:</span> <span class="n">form</span><span class="p">})</span>
</pre></div>
</div>
<p>Notice that we have to pass <a class="reference internal" href="../../ref/request-response.html#django.http.HttpRequest.FILES" title="django.http.HttpRequest.FILES"><tt class="xref py py-attr docutils literal"><span class="pre">request.FILES</span></tt></a>
into the form's constructor; this is how file data gets bound into a form.</p>
<div class="section" id="s-handling-uploaded-files">
<span id="handling-uploaded-files"></span><h3>Handling uploaded files<a class="headerlink" href="#handling-uploaded-files" title="Permalink to this headline">¶</a></h3>
<p>The final piece of the puzzle is handling the actual file data from
<a class="reference internal" href="../../ref/request-response.html#django.http.HttpRequest.FILES" title="django.http.HttpRequest.FILES"><tt class="xref py py-attr docutils literal"><span class="pre">request.FILES</span></tt></a>. Each entry in this
dictionary is an <tt class="docutils literal"><span class="pre">UploadedFile</span></tt> object -- a simple wrapper around an uploaded
file. You'll usually use one of these methods to access the uploaded content:</p>
<dl class="docutils">
<dt><tt class="docutils literal"><span class="pre">UploadedFile.read()</span></tt></dt>
<dd>Read the entire uploaded data from the file. Be careful with this
method: if the uploaded file is huge it can overwhelm your system if you
try to read it into memory. You'll probably want to use <tt class="docutils literal"><span class="pre">chunks()</span></tt>
instead; see below.</dd>
<dt><tt class="docutils literal"><span class="pre">UploadedFile.multiple_chunks()</span></tt></dt>
<dd>Returns <tt class="xref docutils literal"><span class="pre">True</span></tt> if the uploaded file is big enough to require
reading in multiple chunks. By default this will be any file
larger than 2.5 megabytes, but that's configurable; see below.</dd>
<dt><tt class="docutils literal"><span class="pre">UploadedFile.chunks()</span></tt></dt>
<dd><p class="first">A generator returning chunks of the file. If <tt class="docutils literal"><span class="pre">multiple_chunks()</span></tt> is
<tt class="xref docutils literal"><span class="pre">True</span></tt>, you should use this method in a loop instead of <tt class="docutils literal"><span class="pre">read()</span></tt>.</p>
<p class="last">In practice, it's often easiest simply to use <tt class="docutils literal"><span class="pre">chunks()</span></tt> all the time;
see the example below.</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">UploadedFile.name</span></tt></dt>
<dd>The name of the uploaded file (e.g. <tt class="docutils literal"><span class="pre">my_file.txt</span></tt>).</dd>
<dt><tt class="docutils literal"><span class="pre">UploadedFile.size</span></tt></dt>
<dd>The size, in bytes, of the uploaded file.</dd>
</dl>
<p>There are a few other methods and attributes available on <tt class="docutils literal"><span class="pre">UploadedFile</span></tt>
objects; see <a class="reference internal" href="#uploadedfile-objects">UploadedFile objects</a> for a complete reference.</p>
<p>Putting it all together, here's a common way you might handle an uploaded file:</p>
<div class="highlight-python"><div class="highlight"><pre><span class="k">def</span> <span class="nf">handle_uploaded_file</span><span class="p">(</span><span class="n">f</span><span class="p">):</span>
<span class="n">destination</span> <span class="o">=</span> <span class="nb">open</span><span class="p">(</span><span class="s">'some/file/name.txt'</span><span class="p">,</span> <span class="s">'wb+'</span><span class="p">)</span>
<span class="k">for</span> <span class="n">chunk</span> <span class="ow">in</span> <span class="n">f</span><span class="o">.</span><span class="n">chunks</span><span class="p">():</span>
<span class="n">destination</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="n">chunk</span><span class="p">)</span>
<span class="n">destination</span><span class="o">.</span><span class="n">close</span><span class="p">()</span>
</pre></div>
</div>
<p>Looping over <tt class="docutils literal"><span class="pre">UploadedFile.chunks()</span></tt> instead of using <tt class="docutils literal"><span class="pre">read()</span></tt> ensures that
large files don't overwhelm your system's memory.</p>
</div>
<div class="section" id="s-where-uploaded-data-is-stored">
<span id="where-uploaded-data-is-stored"></span><h3>Where uploaded data is stored<a class="headerlink" href="#where-uploaded-data-is-stored" title="Permalink to this headline">¶</a></h3>
<p>Before you save uploaded files, the data needs to be stored somewhere.</p>
<p>By default, if an uploaded file is smaller than 2.5 megabytes, Django will hold
the entire contents of the upload in memory. This means that saving the file
involves only a read from memory and a write to disk and thus is very fast.</p>
<p>However, if an uploaded file is too large, Django will write the uploaded file
to a temporary file stored in your system's temporary directory. On a Unix-like
platform this means you can expect Django to generate a file called something
like <tt class="docutils literal"><span class="pre">/tmp/tmpzfp6I6.upload</span></tt>. If an upload is large enough, you can watch this
file grow in size as Django streams the data onto disk.</p>
<p>These specifics -- 2.5 megabytes; <tt class="docutils literal"><span class="pre">/tmp</span></tt>; etc. -- are simply "reasonable
defaults". Read on for details on how you can customize or completely replace
upload behavior.</p>
</div>
<div class="section" id="s-changing-upload-handler-behavior">
<span id="changing-upload-handler-behavior"></span><h3>Changing upload handler behavior<a class="headerlink" href="#changing-upload-handler-behavior" title="Permalink to this headline">¶</a></h3>
<p>Three settings control Django's file upload behavior:</p>
<dl class="docutils">
<dt><a class="reference internal" href="../../ref/settings.html#std:setting-FILE_UPLOAD_MAX_MEMORY_SIZE"><tt class="xref std std-setting docutils literal"><span class="pre">FILE_UPLOAD_MAX_MEMORY_SIZE</span></tt></a></dt>
<dd><p class="first">The maximum size, in bytes, for files that will be uploaded into memory.
Files larger than <a class="reference internal" href="../../ref/settings.html#std:setting-FILE_UPLOAD_MAX_MEMORY_SIZE"><tt class="xref std std-setting docutils literal"><span class="pre">FILE_UPLOAD_MAX_MEMORY_SIZE</span></tt></a> will be
streamed to disk.</p>
<p class="last">Defaults to 2.5 megabytes.</p>
</dd>
<dt><a class="reference internal" href="../../ref/settings.html#std:setting-FILE_UPLOAD_TEMP_DIR"><tt class="xref std std-setting docutils literal"><span class="pre">FILE_UPLOAD_TEMP_DIR</span></tt></a></dt>
<dd><p class="first">The directory where uploaded files larger than
<a class="reference internal" href="../../ref/settings.html#std:setting-FILE_UPLOAD_MAX_MEMORY_SIZE"><tt class="xref std std-setting docutils literal"><span class="pre">FILE_UPLOAD_MAX_MEMORY_SIZE</span></tt></a> will be stored.</p>
<p class="last">Defaults to your system's standard temporary directory (i.e. <tt class="docutils literal"><span class="pre">/tmp</span></tt> on
most Unix-like systems).</p>
</dd>
<dt><a class="reference internal" href="../../ref/settings.html#std:setting-FILE_UPLOAD_PERMISSIONS"><tt class="xref std std-setting docutils literal"><span class="pre">FILE_UPLOAD_PERMISSIONS</span></tt></a></dt>
<dd><p class="first">The numeric mode (i.e. <tt class="docutils literal"><span class="pre">0644</span></tt>) to set newly uploaded files to. For
more information about what these modes mean, see the <a class="reference external" href="http://docs.python.org/library/os.html#os.chmod">documentation for
os.chmod</a></p>
<p>If this isn't given or is <tt class="xref docutils literal"><span class="pre">None</span></tt>, you'll get operating-system
dependent behavior. On most platforms, temporary files will have a mode
of <tt class="docutils literal"><span class="pre">0600</span></tt>, and files saved from memory will be saved using the
system's standard umask.</p>
<div class="last admonition warning">
<p class="first admonition-title">Warning</p>
<p>If you're not familiar with file modes, please note that the leading
<tt class="docutils literal"><span class="pre">0</span></tt> is very important: it indicates an octal number, which is the
way that modes must be specified. If you try to use <tt class="docutils literal"><span class="pre">644</span></tt>, you'll
get totally incorrect behavior.</p>
<p class="last"><strong>Always prefix the mode with a 0.</strong></p>
</div>
</dd>
<dt><a class="reference internal" href="../../ref/settings.html#std:setting-FILE_UPLOAD_HANDLERS"><tt class="xref std std-setting docutils literal"><span class="pre">FILE_UPLOAD_HANDLERS</span></tt></a></dt>
<dd><p class="first">The actual handlers for uploaded files. Changing this setting allows
complete customization -- even replacement -- of Django's upload
process. See <a class="reference internal" href="#upload-handlers">upload handlers</a>, below, for details.</p>
<p>Defaults to:</p>
<div class="highlight-python"><div class="highlight"><pre><span class="p">(</span><span class="s">"django.core.files.uploadhandler.MemoryFileUploadHandler"</span><span class="p">,</span>
<span class="s">"django.core.files.uploadhandler.TemporaryFileUploadHandler"</span><span class="p">,)</span>
</pre></div>
</div>
<p class="last">Which means "try to upload to memory first, then fall back to temporary
files."</p>
</dd>
</dl>
</div>
</div>
<div class="section" id="s-uploadedfile-objects">
<span id="uploadedfile-objects"></span><h2><tt class="docutils literal"><span class="pre">UploadedFile</span></tt> objects<a class="headerlink" href="#uploadedfile-objects" title="Permalink to this headline">¶</a></h2>
<dl class="class">
<dt id="django.core.files.UploadedFile">
<em class="property">class </em><tt class="descname">UploadedFile</tt><a class="headerlink" href="#django.core.files.UploadedFile" title="Permalink to this definition">¶</a></dt>
<dd></dd></dl>
<p>In addition to those inherited from <a class="reference internal" href="../../ref/files/file.html#django.core.files.File" title="django.core.files.File"><tt class="xref py py-class docutils literal"><span class="pre">File</span></tt></a>, all <tt class="docutils literal"><span class="pre">UploadedFile</span></tt> objects
define the following methods/attributes:</p>
<dl class="docutils">
<dt><tt class="docutils literal"><span class="pre">UploadedFile.content_type</span></tt></dt>
<dd>The content-type header uploaded with the file (e.g. <tt class="docutils literal"><span class="pre">text/plain</span></tt> or
<tt class="docutils literal"><span class="pre">application/pdf</span></tt>). Like any data supplied by the user, you shouldn't
trust that the uploaded file is actually this type. You'll still need to
validate that the file contains the content that the content-type header
claims -- "trust but verify."</dd>
<dt><tt class="docutils literal"><span class="pre">UploadedFile.charset</span></tt></dt>
<dd>For <tt class="docutils literal"><span class="pre">text/*</span></tt> content-types, the character set (i.e. <tt class="docutils literal"><span class="pre">utf8</span></tt>) supplied
by the browser. Again, "trust but verify" is the best policy here.</dd>
<dt><tt class="docutils literal"><span class="pre">UploadedFile.temporary_file_path()</span></tt></dt>
<dd>Only files uploaded onto disk will have this method; it returns the full
path to the temporary uploaded file.</dd>
</dl>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p>Like regular Python files, you can read the file line-by-line simply by
iterating over the uploaded file:</p>
<div class="highlight-python"><div class="highlight"><pre><span class="k">for</span> <span class="n">line</span> <span class="ow">in</span> <span class="n">uploadedfile</span><span class="p">:</span>
<span class="n">do_something_with</span><span class="p">(</span><span class="n">line</span><span class="p">)</span>
</pre></div>
</div>
<p class="last">However, <em>unlike</em> standard Python files, <a class="reference internal" href="#django.core.files.UploadedFile" title="django.core.files.UploadedFile"><tt class="xref py py-class docutils literal"><span class="pre">UploadedFile</span></tt></a> only
understands <tt class="docutils literal"><span class="pre">\n</span></tt> (also known as "Unix-style") line endings. If you know
that you need to handle uploaded files with different line endings, you'll
need to do so in your view.</p>
</div>
</div>
<div class="section" id="s-upload-handlers">
<span id="upload-handlers"></span><h2>Upload Handlers<a class="headerlink" href="#upload-handlers" title="Permalink to this headline">¶</a></h2>
<p>When a user uploads a file, Django passes off the file data to an <em>upload
handler</em> -- a small class that handles file data as it gets uploaded. Upload
handlers are initially defined in the <tt class="docutils literal"><span class="pre">FILE_UPLOAD_HANDLERS</span></tt> setting, which
defaults to:</p>
<div class="highlight-python"><div class="highlight"><pre><span class="p">(</span><span class="s">"django.core.files.uploadhandler.MemoryFileUploadHandler"</span><span class="p">,</span>
<span class="s">"django.core.files.uploadhandler.TemporaryFileUploadHandler"</span><span class="p">,)</span>
</pre></div>
</div>
<p>Together the <tt class="docutils literal"><span class="pre">MemoryFileUploadHandler</span></tt> and <tt class="docutils literal"><span class="pre">TemporaryFileUploadHandler</span></tt>
provide Django's default file upload behavior of reading small files into memory
and large ones onto disk.</p>
<p>You can write custom handlers that customize how Django handles files. You
could, for example, use custom handlers to enforce user-level quotas, compress
data on the fly, render progress bars, and even send data to another storage
location directly without storing it locally.</p>
<div class="section" id="s-modifying-upload-handlers-on-the-fly">
<span id="modifying-upload-handlers-on-the-fly"></span><h3>Modifying upload handlers on the fly<a class="headerlink" href="#modifying-upload-handlers-on-the-fly" title="Permalink to this headline">¶</a></h3>
<p>Sometimes particular views require different upload behavior. In these cases,
you can override upload handlers on a per-request basis by modifying
<tt class="docutils literal"><span class="pre">request.upload_handlers</span></tt>. By default, this list will contain the upload
handlers given by <tt class="docutils literal"><span class="pre">FILE_UPLOAD_HANDLERS</span></tt>, but you can modify the list as you
would any other list.</p>
<p>For instance, suppose you've written a <tt class="docutils literal"><span class="pre">ProgressBarUploadHandler</span></tt> that
provides feedback on upload progress to some sort of AJAX widget. You'd add this
handler to your upload handlers like this:</p>
<div class="highlight-python"><div class="highlight"><pre><span class="n">request</span><span class="o">.</span><span class="n">upload_handlers</span><span class="o">.</span><span class="n">insert</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="n">ProgressBarUploadHandler</span><span class="p">())</span>
</pre></div>
</div>
<p>You'd probably want to use <tt class="docutils literal"><span class="pre">list.insert()</span></tt> in this case (instead of
<tt class="docutils literal"><span class="pre">append()</span></tt>) because a progress bar handler would need to run <em>before</em> any
other handlers. Remember, the upload handlers are processed in order.</p>
<p>If you want to replace the upload handlers completely, you can just assign a new
list:</p>
<div class="highlight-python"><div class="highlight"><pre><span class="n">request</span><span class="o">.</span><span class="n">upload_handlers</span> <span class="o">=</span> <span class="p">[</span><span class="n">ProgressBarUploadHandler</span><span class="p">()]</span>
</pre></div>
</div>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p>You can only modify upload handlers <em>before</em> accessing
<tt class="docutils literal"><span class="pre">request.POST</span></tt> or <tt class="docutils literal"><span class="pre">request.FILES</span></tt> -- it doesn't make sense to
change upload handlers after upload handling has already
started. If you try to modify <tt class="docutils literal"><span class="pre">request.upload_handlers</span></tt> after
reading from <tt class="docutils literal"><span class="pre">request.POST</span></tt> or <tt class="docutils literal"><span class="pre">request.FILES</span></tt> Django will
throw an error.</p>
<p class="last">Thus, you should always modify uploading handlers as early in your view as
possible.</p>
</div>
</div>
<div class="section" id="s-writing-custom-upload-handlers">
<span id="writing-custom-upload-handlers"></span><h3>Writing custom upload handlers<a class="headerlink" href="#writing-custom-upload-handlers" title="Permalink to this headline">¶</a></h3>
<p>All file upload handlers should be subclasses of
<tt class="docutils literal"><span class="pre">django.core.files.uploadhandler.FileUploadHandler</span></tt>. You can define upload
handlers wherever you wish.</p>
<div class="section" id="s-required-methods">
<span id="required-methods"></span><h4>Required methods<a class="headerlink" href="#required-methods" title="Permalink to this headline">¶</a></h4>
<p>Custom file upload handlers <strong>must</strong> define the following methods:</p>
<dl class="docutils">
<dt><tt class="docutils literal"><span class="pre">FileUploadHandler.receive_data_chunk(self,</span> <span class="pre">raw_data,</span> <span class="pre">start)</span></tt></dt>
<dd><p class="first">Receives a "chunk" of data from the file upload.</p>
<p><tt class="docutils literal"><span class="pre">raw_data</span></tt> is a byte string containing the uploaded data.</p>
<p><tt class="docutils literal"><span class="pre">start</span></tt> is the position in the file where this <tt class="docutils literal"><span class="pre">raw_data</span></tt> chunk
begins.</p>
<p>The data you return will get fed into the subsequent upload handlers'
<tt class="docutils literal"><span class="pre">receive_data_chunk</span></tt> methods. In this way, one handler can be a
"filter" for other handlers.</p>
<p>Return <tt class="xref docutils literal"><span class="pre">None</span></tt> from <tt class="docutils literal"><span class="pre">receive_data_chunk</span></tt> to sort-circuit remaining
upload handlers from getting this chunk.. This is useful if you're
storing the uploaded data yourself and don't want future handlers to
store a copy of the data.</p>
<p class="last">If you raise a <tt class="docutils literal"><span class="pre">StopUpload</span></tt> or a <tt class="docutils literal"><span class="pre">SkipFile</span></tt> exception, the upload
will abort or the file will be completely skipped.</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">FileUploadHandler.file_complete(self,</span> <span class="pre">file_size)</span></tt></dt>
<dd><p class="first">Called when a file has finished uploading.</p>
<p class="last">The handler should return an <tt class="docutils literal"><span class="pre">UploadedFile</span></tt> object that will be stored
in <tt class="docutils literal"><span class="pre">request.FILES</span></tt>. Handlers may also return <tt class="xref docutils literal"><span class="pre">None</span></tt> to indicate that
the <tt class="docutils literal"><span class="pre">UploadedFile</span></tt> object should come from subsequent upload handlers.</p>
</dd>
</dl>
</div>
<div class="section" id="s-optional-methods">
<span id="optional-methods"></span><h4>Optional methods<a class="headerlink" href="#optional-methods" title="Permalink to this headline">¶</a></h4>
<p>Custom upload handlers may also define any of the following optional methods or
attributes:</p>
<dl class="docutils">
<dt><tt class="docutils literal"><span class="pre">FileUploadHandler.chunk_size</span></tt></dt>
<dd><p class="first">Size, in bytes, of the "chunks" Django should store into memory and feed
into the handler. That is, this attribute controls the size of chunks
fed into <tt class="docutils literal"><span class="pre">FileUploadHandler.receive_data_chunk</span></tt>.</p>
<p>For maximum performance the chunk sizes should be divisible by <tt class="docutils literal"><span class="pre">4</span></tt> and
should not exceed 2 GB (2<sup>31</sup> bytes) in size. When there are
multiple chunk sizes provided by multiple handlers, Django will use the
smallest chunk size defined by any handler.</p>
<p class="last">The default is 64*2<sup>10</sup> bytes, or 64 KB.</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">FileUploadHandler.new_file(self,</span> <span class="pre">field_name,</span> <span class="pre">file_name,</span> <span class="pre">content_type,</span> <span class="pre">content_length,</span> <span class="pre">charset)</span></tt></dt>
<dd><p class="first">Callback signaling that a new file upload is starting. This is called
before any data has been fed to any upload handlers.</p>
<p><tt class="docutils literal"><span class="pre">field_name</span></tt> is a string name of the file <tt class="docutils literal"><span class="pre"><input></span></tt> field.</p>
<p><tt class="docutils literal"><span class="pre">file_name</span></tt> is the unicode filename that was provided by the browser.</p>
<p><tt class="docutils literal"><span class="pre">content_type</span></tt> is the MIME type provided by the browser -- E.g.
<tt class="docutils literal"><span class="pre">'image/jpeg'</span></tt>.</p>
<p><tt class="docutils literal"><span class="pre">content_length</span></tt> is the length of the image given by the browser.
Sometimes this won't be provided and will be <tt class="xref docutils literal"><span class="pre">None</span></tt>., <tt class="xref docutils literal"><span class="pre">None</span></tt>
otherwise.</p>
<p><tt class="docutils literal"><span class="pre">charset</span></tt> is the character set (i.e. <tt class="docutils literal"><span class="pre">utf8</span></tt>) given by the browser.
Like <tt class="docutils literal"><span class="pre">content_length</span></tt>, this sometimes won't be provided.</p>
<p class="last">This method may raise a <tt class="docutils literal"><span class="pre">StopFutureHandlers</span></tt> exception to prevent
future handlers from handling this file.</p>
</dd>
<dt><tt class="docutils literal"><span class="pre">FileUploadHandler.upload_complete(self)</span></tt></dt>
<dd>Callback signaling that the entire upload (all files) has completed.</dd>
<dt><tt class="docutils literal"><span class="pre">FileUploadHandler.handle_raw_input(self,</span> <span class="pre">input_data,</span> <span class="pre">META,</span> <span class="pre">content_length,</span> <span class="pre">boundary,</span> <span class="pre">encoding)</span></tt></dt>
<dd><p class="first">Allows the handler to completely override the parsing of the raw
HTTP input.</p>
<p><tt class="docutils literal"><span class="pre">input_data</span></tt> is a file-like object that supports <tt class="docutils literal"><span class="pre">read()</span></tt>-ing.</p>
<p><tt class="docutils literal"><span class="pre">META</span></tt> is the same object as <tt class="docutils literal"><span class="pre">request.META</span></tt>.</p>
<p><tt class="docutils literal"><span class="pre">content_length</span></tt> is the length of the data in <tt class="docutils literal"><span class="pre">input_data</span></tt>. Don't
read more than <tt class="docutils literal"><span class="pre">content_length</span></tt> bytes from <tt class="docutils literal"><span class="pre">input_data</span></tt>.</p>
<p><tt class="docutils literal"><span class="pre">boundary</span></tt> is the MIME boundary for this request.</p>
<p><tt class="docutils literal"><span class="pre">encoding</span></tt> is the encoding of the request.</p>
<p class="last">Return <tt class="xref docutils literal"><span class="pre">None</span></tt> if you want upload handling to continue, or a tuple of
<tt class="docutils literal"><span class="pre">(POST,</span> <span class="pre">FILES)</span></tt> if you want to return the new data structures suitable
for the request directly.</p>
</dd>
</dl>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
<div class="yui-b" id="sidebar">
<div class="sphinxsidebar">
<div class="sphinxsidebarwrapper">
<h3><a href="../../contents.html">Table Of Contents</a></h3>
<ul>
<li><a class="reference internal" href="#">File Uploads</a><ul>
<li><a class="reference internal" href="#basic-file-uploads">Basic file uploads</a><ul>
<li><a class="reference internal" href="#handling-uploaded-files">Handling uploaded files</a></li>
<li><a class="reference internal" href="#where-uploaded-data-is-stored">Where uploaded data is stored</a></li>
<li><a class="reference internal" href="#changing-upload-handler-behavior">Changing upload handler behavior</a></li>
</ul>
</li>
<li><a class="reference internal" href="#uploadedfile-objects"><tt class="docutils literal"><span class="pre">UploadedFile</span></tt> objects</a></li>
<li><a class="reference internal" href="#upload-handlers">Upload Handlers</a><ul>
<li><a class="reference internal" href="#modifying-upload-handlers-on-the-fly">Modifying upload handlers on the fly</a></li>
<li><a class="reference internal" href="#writing-custom-upload-handlers">Writing custom upload handlers</a><ul>
<li><a class="reference internal" href="#required-methods">Required methods</a></li>
<li><a class="reference internal" href="#optional-methods">Optional methods</a></li>
</ul>
</li>
</ul>
</li>
</ul>
</li>
</ul>
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<ul><li><a href="../index.html">Using Django</a>
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