Django example

This example shows how to use Dependency Injector with Django.

The example application helps to search for repositories on the Github.

The source code is available on the Github.

Application structure

Application has standard Django project structure. It consists of githubnavigator project package and web application package:

./
├── githubnavigator/
│   ├── __init__.py
│   ├── asgi.py
│   ├── containers.py
│   ├── services.py
│   ├── settings.py
│   ├── urls.py
│   └── wsgi.py
├── web/
│   ├── templates/
│   │   ├── base.html
│   │   └── index.html
│   ├── __init__.py
│   ├── apps.py
│   ├── tests.py
│   ├── urls.py
│   └── views.py
├── manage.py
└── requirements.txt

Container

Declarative container is defined in githubnavigator/containers.py:

"""Containers module."""

from dependency_injector import containers, providers
from github import Github

from . import services


class Container(containers.DeclarativeContainer):

    config = providers.Configuration()

    github_client = providers.Factory(
        Github,
        login_or_token=config.GITHUB_TOKEN,
        timeout=config.GITHUB_REQUEST_TIMEOUT,
    )

    search_service = providers.Factory(
        services.SearchService,
        github_client=github_client,
    )

Container instance is created in githubnavigator/__init__.py:

"""Project package."""

from .containers import Container
from . import settings


container = Container()
container.config.from_dict(settings.__dict__)

Views

View has dependencies on search service and some config options. The dependencies are injected using Wiring feature.

Listing of web/views.py:

"""Views module."""

from typing import List

from django.http import HttpRequest, HttpResponse
from django.shortcuts import render
from dependency_injector.wiring import inject, Provide

from githubnavigator.containers import Container
from githubnavigator.services import SearchService


@inject
def index(
        request: HttpRequest,
        search_service: SearchService = Provide[Container.search_service],
        default_query: str = Provide[Container.config.DEFAULT_QUERY],
        default_limit: int = Provide[Container.config.DEFAULT_LIMIT.as_int()],
        limit_options: List[int] = Provide[Container.config.LIMIT_OPTIONS],
) -> HttpResponse:
    query = request.GET.get("query", default_query)
    limit = int(request.GET.get("limit", default_limit))

    repositories = search_service.search_repositories(query, limit)

    return render(
        request,
        template_name="index.html",
        context={
            "query": query,
            "limit": limit,
            "limit_options": limit_options,
            "repositories": repositories,
        }
    )

App config

Container is wired to the views module in the app config web/apps.py:

"""Application config module."""

from django.apps import AppConfig

from githubnavigator import container


class WebConfig(AppConfig):
    name = "web"

    def ready(self):
        container.wire(modules=[".views"])

Tests

Tests use Provider overriding feature to replace github client with a mock web/tests.py:

"""Tests module."""

from unittest import mock

from django.urls import reverse
from django.test import TestCase
from github import Github

from githubnavigator import container


class IndexTests(TestCase):

    def test_index(self):
        github_client_mock = mock.Mock(spec=Github)
        github_client_mock.search_repositories.return_value = [
            mock.Mock(
                html_url="repo1-url",
                name="repo1-name",
                owner=mock.Mock(
                    login="owner1-login",
                    html_url="owner1-url",
                    avatar_url="owner1-avatar-url",
                ),
                get_commits=mock.Mock(return_value=[mock.Mock()]),
            ),
            mock.Mock(
                html_url="repo2-url",
                name="repo2-name",
                owner=mock.Mock(
                    login="owner2-login",
                    html_url="owner2-url",
                    avatar_url="owner2-avatar-url",
                ),
                get_commits=mock.Mock(return_value=[mock.Mock()]),
            ),
        ]

        with container.github_client.override(github_client_mock):
            response = self.client.get(reverse("index"))

        self.assertContains(response, "Results found: 2")

        self.assertContains(response, "repo1-url")
        self.assertContains(response, "repo1-name")
        self.assertContains(response, "owner1-login")
        self.assertContains(response, "owner1-url")
        self.assertContains(response, "owner1-avatar-url")

        self.assertContains(response, "repo2-url")
        self.assertContains(response, "repo2-name")
        self.assertContains(response, "owner2-login")
        self.assertContains(response, "owner2-url")
        self.assertContains(response, "owner2-avatar-url")

    def test_index_no_results(self):
        github_client_mock = mock.Mock(spec=Github)
        github_client_mock.search_repositories.return_value = []

        with container.github_client.override(github_client_mock):
            response = self.client.get(reverse("index"))

        self.assertContains(response, "Results found: 0")

Sources

Explore the sources on the Github.

Sponsor the project on GitHub: