This is a project implementing the blog post by Mbithe Nzomo.

Prerequisites

• Python 2.7

• virtualenv

• Mysql

   $ brew update && brew install mysql

• Flask

   $ pip install Flask

Installation

Download the project

$ git clone git@gitlab.rc.uab.edu:louistw/get_start_flask.git # or your own fork
$ cd get_start_flask

Create and activate your virtualenv

$ virtualenv venv
$ source venv/bin/activate

Install packages needed via pip

$ pip install -r requirement.txt

Setup environment variables

$ export FLASK_ENV=development
$ export FLASK_APP=run.py

Setup your own configuration

$ cp instance/config.py.default instance/config.py
$ vim instance/config.py

Initialize you database

$ flask db init
$ flask db migrate
$ flask db upgrade

In case you are using SQLite, refer to the third problem in Known problem.

Create admin account

$ flask shell
from app.models import Employee
from app import db
#Remember to replace ADMIN_EMAIL, ADMIN_USERNAME, ADMIN_PASSWORD with correct value
admin = Employee(email="ADMIN_EMAIL",username="ADMIN_USERNAME",password="ADMIN_PASSWORD",is_admin=True)
db.session.add(admin)
db.session.commit()

Finally, you can run your app

$ flask run

Resources:

• Part one

• Part two

• Part three

  And might add some of the feature from The Flask Mega-Tutorial.
  The following list is some of the features might be used for User Portal:

• Chapter 2: Templates

• Chapter 10: Email Support

• Chapter 16: Full-Text Search

• Chapter 19: Deployment on Docker Containers

• Chapter 22: Background Jobs

• Chapter 23: APIs

Known Problems

1. flask development mode WARNING

   $ flask run
    * Serving Flask app "run.py"
    * Environment: production
      WARNING: Do not use the development server in a production environment.
      Use a production WSGI server instead.
    * Debug mode: off

   Solution: Add environment variable FLASK_ENV and set it to development

   $ export FLASK_ENV=development

2. ValueError when click on Assign in employees admin page

   file "APP_ROOT/venv/lib/python2.7/site-packages/wtforms/ext/sqlalchemy/fields.py", line 189, in get_pk_from_identity
   ValueError: too many values to unpack

   Solution(for now): Modify line 189 in fields.py from

   188 def get_pk_from_identity(obj):
   189 	cls, key = identity_key(instance=obj)
   190 	return ':'.join(text_type(x) for x in key)

   to

   188 def get_pk_from_identity(obj):
   189 	cls, key = identity_key(instance=obj)[:2]
   190 	return ':'.join(text_type(x) for x in key)

3. When use SQLite as database

   OperationalError: (sqlite3.OperationalError) no such table

   Solution1: Move sqlite database file into app directory

   $ mv app.db app/

   Solution2(Preferred): Since the problem is because of relative path, using absolute path will solve it.

   For instance:

   SQLALCHEMY_DATABASE_URI='sqlite:////tmp/app.db'

4. FSADeprecationWarning while accessing database using SQLAlchemy

   APP_ROOT/venv/lib/python2.7/site-packages/flask_sqlalchemy/__init__.py:794: FSADeprecationWarning: SQLALCHEMY_TRACK_MODIFICATIONS
   adds significant overhead and will be disabled by default in the future.
   Set it to True or False to suppress this warning.

   Solution1: Set SQLALCHEMY_TRACK_MODIFICATIONS to False/True at line 789 in flask_sqlalchemy/__init__.py

   788 track_modifications = app.config.setdefault(
   789 	'SQLALCHEMY_TRACK_MODIFICATIONS', False
   790 )

   Solution2(Preferred): Add SQLALCHEMY_TRACK_MODIFICATIONS in config.py ecb8e620