wired

An inversion-of-control (IoC) container for building decoupled, extensible, configurable, pluggable applications.

Have a large application where you want to decrease coupling between components? Need to supply configuration to your application’s various services? Want to make a pluggable application where others can supply services?

Inversion of Control and Dependency Injection are two patterns commonly used for these goals.

wired is an implementation of an inversion-of-control (IoC) container and may be used as the core of a dependency injection (DI) framework or simply as a way to separate config-time from runtime for services in an application. It also provides caching such that a container maintains a local copy of each service as they are instantiated.

wired aims to scale down to the simplest cases and scale up to very large, custom systems. It has one dependency and that dependency has one dependency.

Installation

Stable release

To install wired, run this command in your terminal:

$ pip install wired

If you don’t have pip installed, this Python installation guide can guide you through the process.

From sources

The sources for wired can be downloaded from the Github repo.

$ git clone https://github.com/mmerickel/wired.git

Once you have a copy of the source, you can install it with:

$ pip install -e .

Example

Imagine an application where customers walk in the door and you want a Greeter to greet them:

class Greeter:
    def __init__(self, greeting):
        self.greeting = greeting

    def __call__(self):
        return self.greeting + ' !!'

Our application is pluggable: it has a “registry” which processes operations in a “container”:

>>> from wired import ServiceRegistry
>>> registry = ServiceRegistry()

As part of application setup, stuff gets put in the app’s registry. This application is simple: there’s only one Greeter, so we register a “singleton” Greeter instance:

# Greeters are nice...they greet people!
greeter = Greeter(greeting='Hello')

# Register it as a singleton using its class for the "key"
registry.register_singleton(greeter, Greeter)

Here is a function that greets a customer as part of a “container” operation:

def greet_a_customer(container):

    # Ask the *system* via the container to find the `Greeter` for us
    the_greeter = container.get(Greeter)
    greeting = the_greeter()

    return greeting

The app processes a customer by making a container and doing the operation:

>>> container = registry.create_container()
>>> greeting = greet_a_customer(container)
>>> print(greeting)
Hello !!

For a deeper introduction, try the Tour of Wired tutorial.

Indices and tables