File upload
===========

See also :doc:`Scopes chapter </scopes>`.

In your upload form, remember to set ``enctype`` to ``multipart/form-data``.

MyUpload.scalate:

::

  form(method="post" action={url[MyUpload]} enctype="multipart/form-data")
    != antiCsrfInput

    label Please select a file:
    input(type="file" name="myFile")

    button(type="submit") Upload

In ``MyUpload`` action:

::

  import io.netty.handler.codec.http.multipart.FileUpload

  val myFile = param[FileUpload]("myFile")

``myFile`` is an instance of `FileUpload <http://netty.io/4.0/api/io/netty/handler/codec/http/multipart/FileUpload.html>`_.
Use its methods to get file name, move file to a directory etc.

Small files (less than 16 KB) will be saved in memory. Big files will be saved
in the system temporary directory (or the directory specified by
``xitrum.request.tmpUploadDir`` in xitrum.conf), and will be deleted automatically
when the connection is closed or when the response is sent.

Ajax style upload
-----------------

There are many JavaScript libraries that support Ajax style upload. They use
hidden iframe or Flash to send the ``multipart/form-data`` above to the server.
If you are not sure which request parameter the libraries use in the form to send
file, see Xitrum access log.