Repositories¶
The Repository Pattern is a design pattern in Domain-Driven Design (DDD) that abstracts the persistence layer of your application, making it easier to manage and manipulate domain entities. Essentially, repositories act as a kind of in-memory collection for accessing and storing domain entities.
A repository:
- Provides a way to create, read, update, and delete (CRUD) entities.
- Is typically specific to one type of entity (e.g., a UserRepository would handle User entities).
- Hides the details of how entities are stored and retrieved, whether that’s in a database, an API, a file system, etc.
Here is a simple example of how the Repository Pattern might be implemented in Python. This is a very basic example for illustrative purposes, and real-world repositories would likely include more complex logic:
from abc import ABC, abstractmethod
class Repository(ABC):
@abstractmethod
def add(self, entity):
pass
@abstractmethod
def get(self, id):
pass
@abstractmethod
def remove(self, id):
pass
class UserRepository(Repository):
def __init__(self):
self.users = {}
def add(self, user):
self.users[user.id] = user
def get(self, id):
return self.users.get(id)
def remove(self, id):
self.users.pop(id, None)
In this example, we define an abstract base class Repository that outlines the methods we expect a repository to have. Then we create a UserRepository that implements these methods for User entities, storing them in a simple dictionary.
Keep in mind that this is a very simplistic implementation, and a real-world repository would likely involve interacting with a database or another type of persistence layer.
The Repository Pattern provides a clean separation of concerns in your application, isolating the domain logic from the details of the database access. This makes your code easier to maintain, test, and refactor. It also makes it easier to swap out the persistence layer if needed, since all the database-specific code is confined to the repositories.
References¶
Page last modified: 2024-02-13 10:02:46