Demo Mode
=========

Goals
-----

- Allows anyone on the web to anonymously and securely use some aspects of the Plant Tracer web app

- Allow the anonymous demo user to experience plant movement tracking in the app without requiring the user to create an account in a course or to be aware of the movie lifecycle of upload, track, publish, delete

- Disallow the persistence of modifications to all webapp-managed data while in demo mode

Functions
---------

- Will allow:

  - View the list of movies in a single table

  - Play a movie without tracking

  - Click on 'analyze' to show the user interface for playing a movie that has a stored trace

  - Download a CSV representation of movie trace data

- Will not allow:

  - No uploading of movies

  - No deleting of movies

  - No renaming of titles, descriptions

  - No deleting or adding trackpoints

  - No editing any text

  - No re-tracking of movies

Required in the database
------------------------

- Demo mode user with their own API key and course (dbmaint.py --create_course with --demo_email will do this)

- Tracked movies in the demo mode user's course (dbmaint.py --create_course with --demo_email will automatically inserts all the movies it finds in tests/data into the database)

- Currently, be aware that the demo movies must be tracked and published manually after the demo movies are populated into the database

Implementation
--------------

- Only checks for demo mode if ``DEMO_MODE`` environment variable is set to 1

- If ``DEMO_MODE`` is set and there is no user logged in, then we are in DEMO_MODE

- If the logged-in user's demo attribute is true (1), then demo mode is available

- If we are in DEMO_MODE

  - auth.get_user_api_key()

    - If there is a user logged in, we get that user

    - If there is no user logged in, we get the demo user

    - Once we get the demo user, the web browser's API_KEY cookie will be set to the demo user. So logging out will remove it and the immediately set back it

    - (To get out of demo mode, you'll need to click on a link that has a different API key)

- ``user_demo`` JavaScript global variable set to ``1`` (if in demo mode)

- ``user_demo`` Jinja2 variable will get set to ``1`` (otherwise it is ``0``)

- More straightforward than conditional page rendering is using css classes to control the
  displaying of HTML elements for demo mode

  - Class ``demo`` elements display only if in demo mode
  - Class ``nodemo`` elements display only if not in demo mode

Troubleshooting/Development Note
--------------------------------

Plant-Tracer webapp creates an api_key-<database name> cookie in order to tracker
the login state of a session. Sometimes this cookie does not clear itself upon logout
and it is necessary to manually delete the cookie, especially in order to have a valid
demo mode enabled.

Here is an example of such a cookie:

.. image:: media/PlantTracerCookieExample.png