- Demo
- How to Build the project
- Project explanation
- EAV explanation
- Test Coverage
- Code Style
- References
https://loansforgoodfrontend-06732fd2e7f8.herokuapp.com/
https://loans-for-good-backend-55c8893b4944.herokuapp.com/admin/
To build the project, you have to download this repo and the frontend one. After that, create an app tree like this
(root)
├── loans_for_good_backend
│ ├── (this repo)
├── loans_for_good_frontend
└── docker-compose.yml
and use this docker-compose.yml, setting the following config-vars as your preference or use the current ones from the example (just to test the app)
POSTGRES_DB=
POSTGRES_USER=
POSTGRES_PASSWORD=
DEBUG=
DATABASE_URL=
REACT_APP_API_HOSTNAME=
REDIS_URL=
version: '3.8'
services:
db:
image: postgres:13
volumes:
- postgres_data:/var/lib/postgresql/data
environment:
POSTGRES_DB: mydatabase
POSTGRES_USER: myuser
POSTGRES_PASSWORD: mypassword
backend:
build:
context: ./loans_for_good_backend
command: ["python", "manage.py", "runserver", "0.0.0.0:8000"]
volumes:
- ./loans_for_good_backend:/app
ports:
- "8000:8000"
depends_on:
- db
environment:
DEBUG: 'True'
DATABASE_URL: postgresql://myuser:mypassword@db:5432/mydatabase
REDIS_URL: redis://redis:6379/0
frontend:
build:
context: ./loans_for_good_frontend
ports:
- "3000:3000"
depends_on:
- backend
volumes:
- ./loans_for_good_frontend:/app
environment:
REACT_APP_API_HOSTNAME: http://localhost:8000
redis:
image: "redis:latest"
ports:
- "6379:6379"
celery:
build:
context: ./loans_for_good_backend
command: celery -A loans_for_good worker --loglevel=info
volumes:
- ./loans_for_good_backend:/app
depends_on:
- db
- redis
environment:
DATABASE_URL: postgresql://myuser:mypassword@db:5432/mydatabase
REDIS_URL: redis://redis:6379/0
volumes:
postgres_data:
Create an superuser to access localhost:8000/admin panel to create new Attributes. To do this, execute:
docker ps
# Check the container ID of backend container, in my case above, it's 3a09cf8078cd
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
8000889d73da digital_sys_celery "celery -A loans_for…" 2 hours ago Up 6 minutes digital_sys_celery_1
341acdaf85aa redis:latest "docker-entrypoint.s…" 2 hours ago Up 6 minutes 0.0.0.0:6379->6379/tcp, :::6379->6379/tcp digital_sys_redis_1
1f99eb2d240c digital_sys_frontend "docker-entrypoint.s…" 2 hours ago Up 6 minutes 0.0.0.0:3000->3000/tcp, :::3000->3000/tcp digital_sys_frontend_1
3a09cf8078cd digital_sys_backend "python manage.py ru…" 2 hours ago Up 6 minutes 0.0.0.0:8000->8000/tcp, :::8000->8000/tcp digital_sys_backend_1
ad5ed0dc7973 postgres:13 "docker-entrypoint.s…" 30 hours ago Up 6 minutes 5432/tcp digital_sys_db_1
# open container bash
docker exec -it <container-id> bash
# create super user
python manage.py createsuperuser
The project simulates a financial company which loans money. To request a loan, you have to send a Proposal. Users can send, check and refresh the status of all proposals in a SPA. Admin users can register new attributes to proposal and change the status of each proposal.
The project uses an entity called Proposal to persist all the proposals send from frontend to backend. The Proposal is a model with following attributes:
name = models.CharField(max_length=100) -> the name of who is requesting the proposal
document = models.CharField(max_length=20) -> a document from who is requesting the proposal
status = models.CharField(max_length=20, choices=STATUS_CHOICES, default='pending_by_system') -> a status for the proposal (the list of available status is set on proposal/model.py
last_updated = models.DateTimeField(auto_now=True) -> the time of last updat on the proposal
Besides that, the Proposal model is plugged with an EAV entity value attribute pattern which makes possible to register new attributes to proposal, like city, address_line, state, current_job or whatever. The new attributes registration occurs on Django Admin and uses django-eav-2 lib under the hood. All new attributes registered in Django Admin will be sent dinamically to frontend. Further explanations of how django-eav2 works will be discuss latter.
Finnaly, we'are using an external API to send the proposal fields to our internal system to be 'approved' or 'denied', using a background job for that, plugged in Celery and Redis
We choose to use EAV pattern since the company needs to register new attributes dinamically in the Django Admin panel. By the limitations of ORM (Data Integrity, Tracebility and Consistency) we cannot do that changing the schema. To do so, we are using the django-eav2 lib which provides a customized solution for it that makes easy to read, create and filter new attributes to a current model
from eav.models import Attribute
Attribute.objects.create(name='City', slug='city', datatype=Attribute.TYPE_TEXT)
Attribute.objects.create(name='Job Title', slug='job_title', datatype=Attribute.TYPE_TEXT)
- Select the Data Type (Text suggested)
- Give a human name to
Attribute - Select
proposaland Entity Content Type - Save
# create a proposal
proposal = Proposal.objects.create(name='Jose', document='123', eav__city='RJ', eav__job_title='Engineer')
# to read a custom attributes registered in Attribute model (like city or job_title)
proposal.eav.city
proposal.eav.job_title
# or
proposal.eav_values.all()
# as mentioned before
Proposal.objects.create(name='Jose', document='123', eav__city='RJ')
# or
proposal = Proposal.objects.create(name='Jose', document='123')
proposal.eav.city = 'RJ'
proposal.eav.job_title = 'Engineer'
proposal.save()
Proposal.objects.filter(eav__city='RJ')
To execute the tests, run:
coverage run manage.py test
To check test coverage:
coverage report
Full test coverage output:
Name Stmts Miss Cover
-----------------------------------------------------------------------
loans_for_good/__init__.py 0 0 100%
loans_for_good/celery.py 7 0 100%
loans_for_good/settings.py 30 0 100%
loans_for_good/urls.py 3 0 100%
manage.py 12 2 83%
proposal/__init__.py 0 0 100%
proposal/admin.py 17 0 100%
proposal/apps.py 4 0 100%
proposal/migrations/0001_initial.py 5 0 100%
proposal/migrations/0002_proposal_last_updated.py 4 0 100%
proposal/migrations/0003_alter_proposal_status.py 4 0 100%
proposal/migrations/__init__.py 0 0 100%
proposal/models.py 9 0 100%
proposal/serializers.py 11 0 100%
proposal/services.py 5 0 100%
proposal/tasks.py 10 0 100%
proposal/tests/__init__.py 0 0 100%
proposal/tests/test_services.py 30 1 97%
proposal/tests/test_tasks.py 32 1 97%
proposal/tests/test_views.py 36 0 100%
proposal/urls.py 4 0 100%
proposal/views.py 31 0 100%
-----------------------------------------------------------------------
TOTAL 254 4 98%
In this code base we're using the PEP8 style. We configured a pre-commit hooker to prevent us to commit without PEP8 format. To run autofix, before commits execute:
pre-commit run --all-files
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