Domain-Driven Design (DDD) basics in Microservices - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to identify the core building block of DDD that represents a real-world concept.

Microservices

class [1]:
    def __init__(self, id, name):
        self.id = id
        self.name = name

Drag options to blanks, or click blank then click option'

ARepository

BService

CEntity

DFactory

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing Entities with Services or Repositories.

An Entity is a core DDD building block representing an object with a unique identity.

2fill in blank

medium

Complete the code to define a DDD pattern that encapsulates domain logic without identity.

Microservices

class [1]:
    def calculate_discount(self, amount):
        return amount * 0.1

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AValueObject

BEntity

CRepository

DAggregate

Attempts:

3 left

💡 Hint

Common Mistakes

Using Entity instead of Value Object for simple data.

A Value Object represents a descriptive aspect of the domain without identity, focusing on attributes.

3fill in blank

hard

Fix the error in the code to correctly represent a DDD Repository interface.

Microservices

class User[1]:
    def find_by_id(self, user_id):
        pass

Drag options to blanks, or click blank then click option'

AService

BAggregate

CFactory

DRepository

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing Repository with Service or Factory.

A Repository abstracts data access and retrieval for Entities in DDD.

4fill in blank

hard

Fill both blanks to complete the Aggregate root pattern that controls access to related Entities.

Microservices

class Order[1]:
    def __init__(self, order_id):
        self.order_id = order_id
        self.items = []

    def add_item(self, item):
        self.items[2](item)

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AAggregate

Bappend

Cextend

DService

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'extend' instead of 'append' to add a single item.

An Aggregate is a cluster of domain objects treated as a single unit. The root controls access. The append method adds an item to the list.

5fill in blank

hard

Fill all three blanks to complete a DDD Service method that processes a payment.

Microservices

class Payment[1]:
    def process(self, amount, method):
        if method == 'credit_card':
            return self.[2](amount)
        else:
            return self.[3](amount)

    def charge_credit_card(self, amount):
        pass

    def charge_paypal(self, amount):
        pass

Drag options to blanks, or click blank then click option'

AService

Bcharge_credit_card

Ccharge_paypal

DRepository

Attempts:

3 left

💡 Hint

Common Mistakes

Using Repository instead of Service for business logic.

A Service contains domain logic that doesn't naturally fit Entities or Value Objects. The method calls the correct charging function based on payment method.