A simple backend server using Python, Flask, Connexion, Marshmallow and SQLAlchemy.

The requirement only specified CSV for the data, but in many ways SQLAlchemy is easier. So that's what I did.

Flask_CORS is installed because otherwise I couldn't access my server from the client when both are running on localhost.

The only trick is that SQLAlchemy really wants a primary key and this table specification doesn't need one. So I added a row-id column to make SQLAlchemy happy.

I stored the timestamp data as an epoch number at UTC. This is the easiest storage format for dates which can be easily turned back into a date object as needed.

There is a a simple user interface, I didn't do too much with it. It does work to a point.

The API and the UI.

The API is defined with Swagger, so the specification is browseable here.

If you navigate to http://localhost:5000/api/ui, you will find the API doc to the server requests.

Browse here to get to the server side UI. It's just a sanity check really

There is a UI project that works with this server in this repo.

ToDo.

I need to add some tests. Just to make sure what little is there really works. :-)

these are the goals. On verra.

Front (client side)

It should include three main elements:

1- A graph of inventory level(y-axis) vs. date(x-axis) of the selected product

2- Table of data filtered on the selected product: product_id; product_name; date; inventory_level

3- Dropdown/Select option to choose the product ID or product name to visualize

4- (Bonus) Add a button that allows data table editing. Add the possibility to change the "inventory level" and send request to change it in the back-end

5- (Bonus) Add the possibility to choose multiple products and visualize them in the same graph

Back (server side)

Storing the data in a simple flat file. Implement a simple API (post, get,...).

Unit test

Write some basic unit test (client and server side)

Annexe

Constraints

1. front-end code and back-end code are separated in two different projects

2. Communication between back and front is done by a rest API or GaphQL

Type of data

You can create the sample of data you want with at least those elements:

product_id(int); product_name(String); date(String: "dd-mm-yyyy"); inventory_level(int)

How to get this running.

This is a python3 project.

Create a virtual env how you like.

pip install connexion[swagger-ui]

pip install Flask-SQLAlchemy flask-cors flask-marshmallow marshmallow-sqlalchemy marshmallow

Each time you run this the database will be recreated.

python build_database.py

Once there is a database you can run the server. python server.py