Introduction

Object dependency management system based on dry-container and dry-auto_inject allowing you to configure reusable components in any environment, set up their load-paths, require needed files and instantiate objects automatically with the ability to have them injected as dependencies.

This library relies on very basic mechanisms provided by Ruby, specifically require and managing $LOAD_PATH. It doesn’t use magic like automatic const resolution, it’s pretty much the opposite and forces you to be explicit about dependencies in your applications.

It does a couple of things for you:

  • Provides an abstract dependency container implementation
  • Handles $LOAD_PATH configuration
  • Loads needed files using require
  • Resolves object dependencies automatically
  • Supports auto-registration of dependencies via file/dir naming conventions
  • Supports multi-system setups (ie your application is split into multiple sub-systems)

To put it all together, this allows you to configure your system in a way where you have full control over dependencies and it’s very easy to draw the boundaries between individual components.

This comes with a bunch of nice benefits:

  • Your system relies on abstractions rather than concrete classes and modules
  • It helps in decoupling your code from 3rd party code
  • It makes it possible to load components in complete isolation. In example you can run a single test for a single component and only required files will be loaded, or you can run a rake task and it will only load the things it needs.
  • It opens up doors to better instrumentation and debugging tools

You can use dry-system in a new application or add it to an existing application. It should Just Work™ but if it doesn’t please report an issue.

Example

This library is the backbone of dry-web, if you’d like to see a full-blown application example check out Berg. Please notice that dry-system is framework agnostic, in fact, it could be treated as a toolkit for building frameworks, as it provides facilities that are typically needed by frameworks.

Rails support

There’s no dedicated railtie for dry-system yet but we’d like to provide one at some point. Please get in touch if you’re interested in helping with this.

Credits

  • dry-system has been extracted from an experimental project called Rodakase created by solnic. Later on Rodakase was renamed to dry-web.
  • System/Component and lifecycle triggers are inspired by Clojure’s component library by Stuart Sierra