How to create a proper inheritance with dependencies?-CodePudding

While working on my Unity project, I created an abstract class and stored a to reference it as a field. I then called its function Init on Start in order to pass to it its needed references.

So let's say I have an abstract class:

public abstract class Base : MonoBehaviour
{
    protected BaseTool _baseTool; // A references that every inheritor uses
    
    public virtual void Init(BaseTool baseTool)
    {
        _baseTool = baseTool;
    }

    ... // More functuality
}

Now I store it as a field as below:

public class Foo : MonoBehaviour
{
    [SerializeField]
    private Base _base;

    [SerializeField]
    BaseTool _baseTool;

    void Start()
    {
        _base.Init(_baseTool);
    }
}

And now I have an inheritor:

public class Inheritor1 : Base 
{
    public override Init(BaseTool baseTool)
    {
        base.Init(baseTool);
    }

    ... // More functuality
}

So far everything is good. However, let's say I now have another inheritor which also has a dependency on another tool:

public class Inheritor2 : Base 
{
    private Inheritor2Tool _inheritor2Tool; // The dependency
}

That means, that if I want to override Init with Inheritor2 (so I'll be able to call Init in Foo and initialize whatever inheritor is stored inside the field _base) I'll need to change the whole Init signature to Init(BaseTool baseTool, Inheritor2Tool inheritor2Tool) meanwhile only Inheritor2 will use the new parameter Inheritor2Tool inheritor2Tool.

That seems very wrong to me, but I don't know how I can avoid this. So what are my options?

CodePudding user response：

Solution found thanks to the helper below in the comments (thank you very much!). The solution is dependency injection. I'll link 2 videos (one of them provided by the helper) and one tutorial playlist that explain the problem and the solution:

What is dependency injection in Unity?

Zenject (dependency injection framework for Unity) tutorial series.

Zenject (dependency injection framework for Unity) tutorial.