pyramid_di

Easier service location and dependency injection for Pyramid.

Usage

Define services:

# app/services/__init__.py

from .my import MyService
from .another import AnotherService

# app/services/my.py
from pyramid_di import service, RequestScopedBaseService, autowired

@service()
class MyService(RequestScopedBaseService):
    def my_method(self):
        return 'foobar'

# app/services/another.py
from pyramid_di import service, RequestScopedBaseService, autowired
from .my import MyService

@service()
class AnotherService(RequestScopedBaseService):
    dependency = autowired(MyService)

    def another_method(self):
        return self.dependency.my_method()

Setup when creating the Pyramid app:

# Pyramid setup code:
from pyramid.config import Configurator

with Configurator() as config:
    config.include('pyramid_di')
    config.scan_services('app.services')

Use in views:

from pyramid_di import autowired
from pyramid.view import view_config
from my.services import AnotherService

class MyViews:
    service = autowired(AnotherService)

    def __init__(self, request):
        # self.request is required for autowired to work
        self.request = request

    @view_config(route_name='some_view', renderer='json')
    def some_view(self):
        return self.service.another_method()  # 'foobar'

# alternatively, without class-based views:

@view_config(route_name='some_view')
def some_view(request):
    service = request.find_service(AnotherService)
    service.another_method()  # 'foobar'

Mocking services for testing

class MockService:
    def another_method(self):
        return 'mocked'

def test_views():
    request = DummyRequest()
    my_views = MyViews(request)
    my_views.service = MockService()
    assert my_views.some_view() == 'mocked'

Development

Dev setup:

$ python3 -m venv venv
$ pip install -e '.[dev]'

Tests are run with pytest:

$ pytest

Changes

0.4.1

• 2021-03-19 The request-scoped services were not quite correct as they could have been instantiated twice
  • once in the traversal-time and the other time after context was set. Now the context is forced to None for the request-scoped services.

0.4.0

• 2020-11-25 Python 3.6+ only; better test coverage, fixes for scoped services, deprecations and so forth.

0.3.dev0

• 2020-11 Unreleased development version

0.2.dev0

• 2020-11-04 Require Python 3 for cleaner code

0.1

• 2018-03-26 Initial release