Udemy - Create a CRUD Django App

Hosted via Heroku at - https://myems-project.herokuapp.com/

Getting Set up

Installations

• python 2.7 -
• postgreSQL -
• pgAdmin -
• virtualenv-

Additional Resources

• psycorpg - http://initd.org/psycopg/

Setting up our Database

• Open pgAdmin, on our Databases right click and create New Database..
• Restore the database and navigate to our database file from the resources of the tutorial.
• Explore the database by viewing tables and its data.

Virtual Environment - virtualenv

• Create our virtual environment to install python packages just for this project in a folder we can name as venv with virtualenv venv.
• To run our virtual environment within GitBash /Linux - source venv/Scripts/activate
• On windows to run our virtual environment - venv\Scripts\activate.bat
• To deactivate - source venv\Scripts\deactivate

Using Django with virtualenv

• Install django within the virtual env with pip install django

• To create a project within our venv environment and folder - django-admin startproject myems .

• To print out the current packages you've installed within your virtual enviroment pip freeze.

• Create a requirements.txt file with all dependencies with pip freeze > requirements.txt.

• Note: to install a project based on the requirements.txt file

pip install -r requirements.txt

• Edit main settings.py to include the following code for paramters we specified when setting up our database.

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'OPTIONS': {'options': '-c search_path=public'},
        'NAME': 'employees',
        'USER': 'postgres',
        'PASSWORD': '********',
        'HOST': 'localhost',
        'PORT': '5432',
    }
}

• Run pip install django psycopg2 to install psycopg2 within the virtual environment.

• Update requirements.txt file with all dependencies with pip freeze > requirements.txt.

• Run server with python manage.py runserver to check if our app is connected succesfully.

• Note: Change default on server with python manage.py runserver 8083.

• Make migrations python manage.py migrate.

• Control the state of our Db migrations with python manage.py makemigrations myems.

• To use our admin panel, create a super user with python manage.py createsuperuser (User: admin, email: [email protected], password: ******)

Django - Models

Model First Approach

• Add the models.py file to our ems folder and add our imports and classes.
• Use Django meta Data docs to name table or order by etc.
• In the virtual environment run python manage.py makemigrations myems.
• To find out what SQL command was be executed by Django run python manage.py sqlmigrate myems 0001_initial.
• Run migrate after making migrations with python manage.py migrate.
• To add or remove a column after initially setting up the table, just run makemigrations & migrate command again and new migrations files will be created.

Deleting tables

• One approach is commenting out the class and running makemigrations and migrate commands again.
• Another approach is to physically delete the table via pgAdmin. Clean it up by removing related rows in the django_migrations and auth_permission tables. Delete the unused files in the project migrations folder.

Database First Approach

• Add models.py and __init__.py files from myems directory to feedback directory and delete the migrations folder in myems.
• Add feedback directory to installed apps in myems settings.py.
• Make migrations with python manage.py makemigrations feedback. and migrate as well.
• Use python manage.py inspectdb to inspect the DB in an all class format.
• Run python manage.py inspectdb > myems/models.py to save.
• Clean up our new myems models.py.
• Run python manage.py makemigrations.
• Run python manage.py makemigrations myems.
• Fake migrations by python manage.py migrate --fake myems 0001_initial.

Django - QuerySets

• To open the python shell , type python into the terminal.
• To open the django shell, run python manage.py shell.
• In the django shell -

>>> from myems.models import Employee
>>>
>>> querySet = Employee.objects.all()
>>> print querySet

• To overide the results of our data from string representations to the actual data, modify the class from models.py. Restart and run the code above again in the shell.
• Look at other examples of queries in the django-queries.md file.

Django - Admin

• Register Django admin for our EMS data.
• Edit custom fields on our admin page to reflect feedback model.
• Create msg box for editing record using custom fields.

Django - Validators

• docs - https://docs.djangoproject.com/en/1.11/ref/validators/
• Use Django's built in validation for email , max_length etc for our form element.
• Skip Django Create Custom validators tutorial.
• Add admin custom list filters for employee data.

Django - User View Permissions

• Add permissions to addional users to be able to edit data.
• Add users - test, test_2, password-Number@123456
• To Add Django-view-permissions extension.
• Add admin_view_permission to our settings.py to install.
• Run pip install django-admin-view-permission.
• Update requirements.txt with pip freeze > requirements.txt.
• Run python manage.py migrate. If migrations issues exist run python manage.py migrate --fake-initial.
• Add our User to a Group to only be able to read Data.

Django - Responsive

• Install the following package to make our Admin view responsive Django-Flat-Responsive.
• Run pip install django-flat-responsive.
• Add 'flat_responsive', to our installed apps in settings.py.
• To further on the styling add our styling to venv/Lib/site-packages/flat-responsive/templates/admin/base.html.

Django - Custom Admin Header

• Add our custom admin site to our project to change text.

Django - URL Configurations & Response Views

Function based View -

• Add URL http://127.0.0.1:8000/employees/1101/profile/.
• Creare index URL and render with template

Class based View & Generic -

• Difference in design pattern (http method)
• Add templates and add URLS for CRUD operations on employee data.

Django - Templates

• Render the material design template with django and edit settings and import the right packages.

Django - Add Images to our DB

• [Django STD -image] (https://github.com/codingjoe/django-stdimage)
• Install with pip install django-stdimage.
• Add 'stdimage' to installed_apps in settings.py.
• Update with pip freeze > requirements.txt.
• Run makemigrations and then migrate because we have updated models.

Deploying to Heroku

Setting up

• Install Heroku CLI via Installer or npm with npm install -g heroku-cli.
• Verify installation with heroku --version.
• Add static folder and use run python manage.py collectstatic.
• Add Whitenoise Django to serve static files when debug mode is off for production. Run pip install whitenoise.
• Whitenoise Django docs - [http://whitenoise.evans.io/en/stable/django.html].
• Install Gunicorn Production server with pip install gunicorn.
• Install pip install dj-database-url.
• Update with pip freeze > requirements.txt.
• Add runtime.txt and Procfile.

Deployment

• Log in to Heroku via heroku login.
• Make sure you have a git repo initialized.
• Create heroku app with heroku create myems.
• Open app with heroku open.
• To configure our Db - heroku config
• To link up our Db to Heroku use heroku pg:backups restore "https://www.dropbox.com/s/wsdftd8021xx9ew/employee_db_small_heroku_final.backup?dl=1" --confirm myems-project
• To verify use heroku pg:psql and type select (*) from employees;.
• Check hosted link.

Deploying to Amazon S3

Setting up