A Dependency Injection solution from scratch

Here are some notes about what we aim to achieve:

Comply with the PSR-11 standard

• Use the container-interop/container-interop package
• https://packagist.org/packages/container-interop/container-interop

Write the code in TDD style with PHPUnit

• https://packagist.org/packages/phpunit/phpunit

Have a container where we can store services ( = object definitions)

• The object definitions are instances of a Definition class which has class and args properties
• The constructor is used to set the services
• The container is immutable
• The container's has() method tells whether a given identifier exists in the container
• The container's get() method returns an object that is instantiated based on its definition
• Lazy loading: we instantiate an object only when we have to (when someone asks for it via the get() method)
• Object storage: we instantiate an object only once and then store it

Create a builder class

• Resolves all the dependencies in the tree and then compiles the Container class

Auto wiring