Hgraca\MicroDI

A small dependency injection library that uses reflection and a service locator container, to instantiate and recursively resolve, instantiate and inject dependencies.

Installation

To install the library, run the command below and you will get the latest version:

composer require hgraca/micro-di

Usage

Factories

The factories used in Builder::buildFromFactory need to extend Hgraca\MicroDI\FactoryInterface.

The method Builder::buildFromFactory instantiates the factory and calls the create method on it. The arguments given to Builder::buildFromFactory will be used both when instantiating the factory and when calling the create method:

• They will be injected in the __construct() if the arguments keys match any of the dependencies names.
• They will all be injected in the create(), together with whatever is in the container with the key '.context', where is the relevant factory FQCN.

Dependency resolution process

The builder will resolve and instantiate dependencies. The dependencies, both when instantiating and when calling a method with Builder::call, will fe filled in the following priority:

1. By matching the dependencies names with the name of the provided arguments
2. If its a class/interface, it will try to instantiate it, which in turn:
   1. tries to fetch it from the container, by searching for the class/interface fqcn as one of the containers keys
      1. If the key (class/interface fqcn) is found:
         • If its an instance, it will be used (singleton)
         • If its a closure, it will be used to instantiate the required class (singleton)
         • If its a factory, it will be used to build the required class through the method Builder::buildFromFactory, and build a new instance every time (making it not a singleton)
      2. If the key (class/interface fqcn) is not found:
         1. If its a class it will be instantiated (recursively resolving and injecting its dependencies) and it will be cached in the container
         2. If its an interface, an error will be thrown
3. If its not a class/interface it will try to find the dependencies in the container, by their name.
4. If it fails to find all mandatory dependencies, it will throw an error while instantiating the class.

Todo