ioc

Description

Inversion of Control container.

Import

import {
  context,
  iocParam,
  IocClass
} from "dreamkit";

Definition

declare const context: {
  register(
    key: any,
    data: {
      value?: any;
      useClass?: any;
      useFactory?: ($context: typeof context, key: any) => any;
      singleton?: boolean;
    },
  ): typeof context;
  unregister(key: any): typeof context;
  resolve(key: any): unknown;
  fork(): typeof context;
};

Examples

Basic usage

import { context, IocClass, ServiceClass } from "dreamkit";

class Child extends IocClass({}) {
  process(value: string) {
    return value;
  }
}

class CustomChild extends Child {
  override process(value: string): string {
    return value.toUpperCase();
  }
}

class Parent extends IocClass({ Child }) {
  process(value: string) {
    return this.child.process(value);
  }
}

export class TestService extends ServiceClass({ Parent }) {
  onStart() {
    const value0 = this.parent.process("hello");
    const value1 = new Parent({ child: new Child() }).process("hello");
    const value2 = context
      .fork()
      .register(Child, { useClass: CustomChild })
      .resolve(Parent)
      .process("world");
    console.log([value0, value1, value2]); // ["hello", "WORLD"]
  }
}

Optional

import { IocClass, iocParam, ServiceClass } from "dreamkit";

class Child extends IocClass({}) {
  process(value: string) {
    return value;
  }
}

class Parent extends IocClass({ child: iocParam(Child).optional() }) {
  process(value: string) {
    return this.child?.process(value);
  }
}

export class TestService extends ServiceClass({}) {
  onStart() {
    const value1 = new Parent({}).process("hello");
    const value2 = new Parent({
      child: {
        process(value) {
          return value.toUpperCase();
        },
      },
    }).process("world");
    console.log([value1, value2]); // [undefined, "WORLD"]
  }
}