{"id":570,"date":"2024-12-26T12:57:19","date_gmt":"2024-12-26T12:57:19","guid":{"rendered":"https:\/\/docs.sisus.co\/init-args\/?p=570"},"modified":"2026-06-23T06:24:12","modified_gmt":"2026-06-23T06:24:12","slug":"inheritance-and-dependencies","status":"publish","type":"post","link":"https:\/\/docs.sisus.co\/init-args\/problems-and-solutions\/inheritance-and-dependencies\/","title":{"rendered":"Inheritance and Dependencies"},"content":{"rendered":"

Problem:<\/h1>\n

You have a base class that depends on some services.<\/p>\n

You want to create a class that derives from that base class, which depends on some additional services on top of the ones that the base class does.<\/p>\n

class Base : MonoBehaviour<A, B>\r\n{\r\n    \/\/ The base class depends on some services\r\n    A a;\r\n    B b;\r\n\r\n    protected override void Init(A a, B b)\r\n    {\r\n        this.a = a;\r\n        this.b = b;\r\n    }\r\n}\r\n\r\n<\/span>class Derived : Base\r\n{\r\n    \/\/ A derived type depends on some additional services\r\n    C c;\r\n    D d;\r\n}<\/span><\/pre>\n
Since the Derived class must derive from Base, it can not simultaneously derive from MonoBehaviour<A, B, C, D><\/code>.<\/p>\n
How can Derived be defined in such a way that:<\/p>\n
    \n
  1. all four dependencies can be provided to it from the outside,<\/li>\n
  2. and it will be able to acquire the dependencies automatically at the beginning of the Awake event?<\/li>\n<\/ol>\n
    Solution:\u00a0IInitializable<T…><\/span><\/h1>\n
    To make it possible to inject all the objects that your derived class and its base class depend on, implement the IInitializable<T…><\/a> interface, and list the types of all their combined dependencies as generic type arguments of the interface.<\/p>\n
    You will also need to override the bool Init(Context)<\/em> method, to make it acquire all the combined dependencies at the beginning of the Awake event, instead of just the ones that the base class depends on.<\/p>\n
    public class Derived : Base, IInitializable<A, B, C, D>\r\n<\/span>{\r\n    C c;\r\n    D d;\r\n\r\n    \/\/ Implement Init(A, B, C, D) to be able to receive all four dependencies.\r\n    public void Init(A a, B b, C c, D d)\r\n    {\r\n        \/\/ Init the base type\r\n        Init(a, b);\r\n\r\n        \/\/ Init the derived type\r\n        this.c = c;\r\n        this.d = d;\r\n    }\r\n\r\n     \/\/ Override Init(Context) to automatically receive all four dependencies at the beginning of the Awake event.\r\n     protected override bool Init(Context context) => InitArgs.TryGet<Derived, A, B, C, D>(this);\r\n}<\/span><\/pre>\n
    \n
    Problem<\/h1>\n
    You have a base class that does not depend on any services.<\/p>\n
    You want to create a single class that derives from that base class, which does depend on some services.<\/p>\n
    \/\/ The base class with no dependencies\r\nclass Base : MonoBehaviour { }\r\n\r\n<\/span>class Derived : Base\r\n{\r\n    \/\/ A derived type depends on some services\r\n    A a;\r\n    B b;\r\n}<\/span><\/pre>\n
    Since the Derived class must derive from Base, it can not simultaneously derive from MonoBehaviour<A, B><\/code>.<\/p>\n
    How can Derived be defined in such a way that:<\/p>\n
      \n
    1. the two dependencies can be provided to it from the outside,<\/li>\n
    2. and it will be able to acquire the dependencies automatically at the beginning of the Awake event?<\/li>\n<\/ol>\n
      Solution: IInitializable<T…><\/span><\/h1>\n
      To make it possible to inject all the objects that your derived class and its base class depend on, implement the IInitializable<T…><\/a> interface, and list the types of all their combined dependencies as generic type arguments of the interface.<\/p>\n
      You will also need to use InitArgs.TryGet during the Awake event<\/span>, to make it acquire all the combined dependencies automatically.<\/p>\n
      public class Derived : Base, IInitializable<A, B>\r\n<\/span>{\r\n    A a; B b;\r\n\r\n    \/\/ Implement Init(A, B) to be able to receive two Init arguments\r\n    public void Init(A a, B b)\r\n    {\r\n        this.a = a;\r\n        this.b = b;\r\n    }\r\n\r\n    \/\/ Use InitArgs.TryGet to receive Init arguments at the beginning of the Awake event.\r\n    void Awake() => InitArgs.TryGet<Derived, A, B>(this);\r\n}<\/span><\/pre>\n
      \n
      Problem<\/h1>\n
      You have a common base class that does not depend on any services.<\/p>\n
      You want to create a several classes that derives from that base class, which depend on different services.<\/p>\n
      \/\/ The base class with no dependencies\r\nnamespace MyNamespace\r\n{\r\n    public abstract class BaseBehaviour : MonoBehaviour { }\r\n}\r\n\r\n<\/span>class Derived1 : BaseBehaviour\r\n{\r\n    \/\/ Derived types depend on some services\r\n    A a;\r\n    B b;\r\n}\r\n\r\nclass Derived2 : BaseBehaviour\r\n{\r\n   C c;\r\n   D d;\r\n}\r\n<\/span><\/pre>\n
      Since the derived classes must derive from BaseBehaviour, they can not simultaneously derive from MonoBehaviour<T...><\/code>. So how can derived types be created that contain all functionality both from your custom base class and from MonoBehaviour<T...><\/code>?<\/p>\n
      Solution: Base Class Generator<\/h1>\n
      You can use a Base Class Generator<\/strong> to generate new custom base classes similar to MonoBehaviour<T...><\/code>, but based on your own base type.<\/p>\n
      To create a new base class generator for your type, perform the following steps:<\/p>\n
        \n
      1. Select Create > Init(args) > Base Class Generator<\/code> in the Project window.<\/li>\n
      2. Add the namespace that contains your base class to the Using Statements list.<\/li>\n
      3. Add the desired name for the generated base classes to the Class Name<\/strong> field.<\/li>\n
      4. Add the type name of your base type to the Derives From<\/strong> field.<\/li>\n
      5. Click Generate<\/strong> to generate your base classes.<\/li>\n<\/ol>\n
        \"\"<\/p>\n
        After this your types can derive from one the generated generic base types, just like they would from MonoBehaviour<T...><\/code>.<\/p>\n
        public class Derived1 : BaseBehaviour<A, B>\r\n<\/span>{\r\n    A a; B b;\r\n\r\n    protected override void Init(A a, B b)\r\n    {\r\n        this.a = a;\r\n        this.b = b;\r\n    }\r\n}<\/span><\/pre>\n
        If your base class also does have some dependencies, but only to global services<\/a>, and you’d still want to use the Base Class Generator with it, you could make it implement IInitializable<T...><\/code> and then have it automatically resolve its own dependencies during its Awake event.<\/p>\n
        \/\/ The base class with no dependencies\r\nnamespace MyNamespace\r\n{\r\n    public abstract class BaseBehaviour : MonoBehaviour, IInitializable<ILogger>\r\n    {\r\n        ILogger logger;\r\n\r\n        public void Init(ILogger logger) => this.logger = logger;\r\n\r\n        protected virtual void Awake() => InitArgs.TryGet<BaseBehaviour, ILogger>(this);\r\n    }\r\n}<\/span><\/pre>\n
         If you do this, make sure to define the Awake method in your base class as protected virtual<\/code>, so that the generated base classes can override it.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"
        Problem: You have a base class that depends on some services. You want to create a class that derives from that base class, which depends on some additional services on top of the ones that the base class does. class Base : MonoBehaviour<A, B> { \/\/ The base class depends on some services A a; ..<\/p>\n
        <\/div>\n
        Read more<\/a><\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[9],"tags":[],"_links":{"self":[{"href":"https:\/\/docs.sisus.co\/init-args\/wp-json\/wp\/v2\/posts\/570"}],"collection":[{"href":"https:\/\/docs.sisus.co\/init-args\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/docs.sisus.co\/init-args\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/docs.sisus.co\/init-args\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/docs.sisus.co\/init-args\/wp-json\/wp\/v2\/comments?post=570"}],"version-history":[{"count":17,"href":"https:\/\/docs.sisus.co\/init-args\/wp-json\/wp\/v2\/posts\/570\/revisions"}],"predecessor-version":[{"id":1111,"href":"https:\/\/docs.sisus.co\/init-args\/wp-json\/wp\/v2\/posts\/570\/revisions\/1111"}],"wp:attachment":[{"href":"https:\/\/docs.sisus.co\/init-args\/wp-json\/wp\/v2\/media?parent=570"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/docs.sisus.co\/init-args\/wp-json\/wp\/v2\/categories?post=570"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/docs.sisus.co\/init-args\/wp-json\/wp\/v2\/tags?post=570"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}