Example: Upload and Download Files with Plotly Dash
===================================================

This example demonstrates uploading and downloading files to and from a Plotly
Dash app. This example simply saves the files to disk and serves them back to
user, but if you want to process uploaded files, try adapting the
``save_file()`` function in this example.

Python Source Code
------------------

.. literalinclude:: dash_file_upload_download.py

Deployment
----------

Assuming that you store this file as ``myapp.py`` to
``/project/myappdirectory`` in your project workspace, the settings you need to
deploy this in Faculty are:

* **Working Directory:** ``/project/myappdirectory``
* **Python Module:** ``myapp``
* **Python Object:** ``server`` (the name of the Flask object used by Dash)

You can also follow the instructions in :ref:`developing_plotly_dash_apps` to
run the app in development mode.

Usage
-----

The app provides a widget to upload files, and maintains a list of download
links for previously uploaded files:

.. image:: images/dash_file_upload_download.png

Only files that fit in memory on the server you run your app on will work,
however for most applications this will not be a problem.