Dependency Injection

依赖项是指某个类执行其功能所需的服务或对象。依赖项注入（DI）是一种设计模式，在这种设计模式中，类会从外部源请求依赖项而不是创建它们。

Cosmic DI 框架会在实例化某个 Service 类或组件时为其提供依赖。

How to work

Cosmic DI 的核心由 InversifyJS 实现，你可以参考 InversifyJS 来创建、注册Service，以及在模块和组件中获取 DI 实例。

DI in Service

/** color-set.ts **/
@injectable()
export class ColorSet {
  constructor(
    @inject(ColorSetRoot) private root: HTMLElement,
    @inject(AppearanceService) private aps: AppearanceService,
    ) {
      // ..
    }
    // ..
}

DI in Svelte

<script lang="ts">
  import inject  from '@cosmic-base/parts/ioc/inject';
  import { AppearanceService } from '@cosmic-workbench/services/appearance-service';

  const aps: AppearanceService = inject(AppearanceService);
</script>

AppearanceType is {aps.type()}