Module 2

Ontologies are formal, explicit definitions of terms within a domain and their relationships to other terms, encompassing a collection of concepts (such as entities, objects, domains, processes, goals, and outcomes), along with properties, relationships, constraints, and axioms (Arnaut, Oliveira & Lima, 2010).

Below is a high-level ontology for the online retailer system to be developed in unit 11:

1. User
   • Properties:
     • username: Unique identifier for each user.
     • password: Hashed password for user authentication.
     • is_admin: Boolean indicating if the user has administrative privileges.
   • Relationships:
     • Places Orders: A user can place multiple orders.
     • Views Products and Orders: Users can view products available in the system and their past orders.
     • Admin Privileges: A user with admin privileges can view system stats and update them.
2. Product
   • Properties:
     • name: Name of the product, acting as a unique identifier.
     • price: Price of the product.
   • Relationships:
     • Associated with Orders: Product is a part of orders placed by users.
     • Viewed by Users: Users can view products available in the system.
3. Order
   • Properties:
     • order_id: Unique identifier for each order.
     • username: User who placed the order.
     • product_name: The product associated with the order.
     • quantity: Number of products in the order.
     • total: Total cost of the order.
   • Relationships:
     • Placed by User: Each order is associated with a user.
     • Viewed by Users: Users can view their past orders.

			
from flask import Flask
from flask_restful import Api, Resource, reqparse
	
app = Flask(__name__)
api = Api(app)
	
users = [
	{
		"name": "James",
		"age": 30,
		"occupation": "Network Engineer"
	},
	{
		"name": "Ann",
		"age": 32,
		"occupation": "Doctor"
	},
	{
		"name": "Jason",
		"age": 22,
		"occupation": "Web Developer"
	}
]
	
class User(Resource):
	def get(self, name):
		for user in users:
			if(name == user["name"]):
				return user, 200
		return "User not found", 404
	
	def post(self, name):
		parser = reqparse.RequestParser()
		parser.add_argument("age")
		parser.add_argument("occupation")
		args = parser.parse_args()
	
		for user in users:
			if(name == user["name"]):
				return "User with name {} already exists".format(name), 400
	
		user = {
			"name": name,
			"age": args["age"],
			"occupation": args["occupation"]
		}
		users.append(user)
		return user, 201
	
	def put(self, name):
		parser = reqparse.RequestParser()
		parser.add_argument("age")
		parser.add_argument("occupation")
		args = parser.parse_args()
	
		for user in users:
			if(name == user["name"]):
				user["age"] = args["age"]
				user["occupation"] = args["occupation"]
				return user, 200
		
		user = {
			"name": name,
			"age": args["age"],
			"occupation": args["occupation"]
		}
		users.append(user)
		return user, 201
	
	def delete(self, name):
		global users
		users = [user for user in users if user["name"] != name]
		return "{} is deleted.".format(name), 200
		
api.add_resource(User, "/user/<string:name>")

app.run(debug=True)