Example Flask App

Example flask app based on framework of Peter Mooring

Initial notes:

• bootstrap_flask is needed to avoid error jinja2.exceptions.TemplateNotFound: bootstrap/nav.html

• Following modules must be installed:

  • flask

  • flask_wtf

  • flask_bootstrap4

  • sqlalchemy

  • bootstrap_flask

  • wtforms_sqlalchemy

After running the initial alembic commands you should see the following output

(venv) pi@rpi3Bimmcff ~/mystuff/flask/gvflask/project$  alembic revision -m "First revision"

  Generating /home/pi/mystuff/flask/gvflask/project/alembic/versions/aa89aa4df9a9_first_revision.py ...  done

(venv) pi@rpi3Bimmcff ~/mystuff/flask/gvflask/project$  alembic upgrade head

INFO  [alembic.runtime.migration] Context impl SQLiteImpl.

INFO  [alembic.runtime.migration] Will assume non-transactional DDL.

INFO  [alembic.runtime.migration] Running upgrade  -> aa89aa4df9a9, First revision

This will also create the intial database "app.db" for this example app.

Now only the alembic table is created, not yet the tables for the application itself.  To do this, the following must be run:

(venv) pi@rpi3Bimmcff ~/mystuff/flask/gvflask/project$  alembic revision --autogenerate -m "Create the database"

INFO  [alembic.runtime.migration] Context impl SQLiteImpl.

INFO  [alembic.runtime.migration] Will assume non-transactional DDL.

INFO  [alembic.autogenerate.compare] Detected added table 'city'

INFO  [alembic.autogenerate.compare] Detected added table 'hobby'

INFO  [alembic.autogenerate.compare] Detected added table 'friend'

INFO  [alembic.autogenerate.compare] Detected added table 'friend_mtm_hobby'

  Generating /home/pi/mystuff/flask/gvflask/project/alembic/versions/65d5a8dd0649_create_the_database.py ...  done

(venv) pi@rpi3Bimmcff ~/mystuff/flask/gvflask/project$  alembic upgrade head

INFO  [alembic.runtime.migration] Context impl SQLiteImpl.

INFO  [alembic.runtime.migration] Will assume non-transactional DDL.

INFO  [alembic.runtime.migration] Running upgrade aa89aa4df9a9 -> 65d5a8dd0649, Create the database

Only now the extra tables are created and can be used.