Question

我正在尝试制作一个通用组件来显示列表资源。我遇到了在HTML中实例化组件的问题。我正在使用此answer来尝试解决问题，但我觉得它不起作用。

我有这个组件

<ion-list>
  <ion-item-sliding *ngFor="let entity of entityList" #item>
    <ion-item (click)="navigateToDetail(entity.id)">
      <ion-avatar item-left>
        <img src="http://modexenergy.com/wp-content/themes/modex_wp/img/avatar.png">
      </ion-avatar>
      <h2>{{ entity.email }}</h2>
      <ion-icon name="arrow-forward" item-right></ion-icon>
    </ion-item>
    <ion-item-options side="right">
      <button ion-button color="danger" (click)="delete(entity.id)">
        <ion-icon name="trash"></ion-icon>Delete
      </button>
    </ion-item-options>
  </ion-item-sliding>
</ion-list>

export class PageListBaseComponent<T extends IHasId> {

    @Input() entityType: T;
    @Input() detailPageType: any;
    public entityList: T[];

    constructor(public navCtrl: NavController, public navParams: NavParams, public baseProvider: ProviderBase<T>) {

        baseProvider.getList().subscribe(entities => {
            this.entityList = entities;
            console.log(entities);
        });
    }

    delete(id: number) {
        console.log(id);
        //this.baseProvider.deleteById(id).subscribe(result => {
        //    console.log(result);
        //});
    }

    navigateToDetail(id: number) {
        console.log('test ' + id)
        this.navCtrl.push(this.detailPageType, { id })
    }
}

我从用户页面初始化它是这样的：

<ion-content padding>
  <page-list-base [entityType]="userType" [detailPageType]="userDetailType">
  </page-list-base>
</ion-content>

export class UsersPage {

  public userType: User;
  public userDetailType: ProfilePage;

  constructor(public navCtrl: NavController, public navParams: NavParams) {
  }
}

这不起作用，因为我的Component引用构造函数中的public baseProvider: ProviderBase<T>，Dependency Inject无法解析该类型。

我希望能够尽可能多地重复使用它。如何正确初始化此通用组件？如果那是不可能的，我怎么能在T结算后迟到了baseProvider？

Answer 1

我通过延迟初始化并使依赖为@Input属性

来解决这个问题

export class PageListBaseComponent<T extends IHasId> {

    @Input() detailPageType: any;
    @Input() set baseProvider(provider: ProviderBase<T>) {
        provider.getList().subscribe(entities =>  {
            this.entityList = entities;
            console.log(entities);
        });
    }

    public entityList: T[];

    constructor(public navCtrl: NavController, public navParams: NavParams) 
    {

    }

    navigateToDetail(id: number) {
        console.log('test ' + id)
        this.navCtrl.push(this.detailPageType, { id })
    }
}

然后我修改页面以接受我们的依赖项的具体实现，

export class UsersPage {

  public userDetailType: any = ProfilePage;

  constructor(public navCtrl: NavController, public navParams: NavParams, public baseProvider: Users) {
      console.log(this.userType);
  }
}

然后我像这样实现组件：

<ion-content padding>
  <page-list-base [detailPageType]="userDetailType" 
      [baseProvider]="baseProvider"></page-list-base>
</ion-content>

在构造函数中使用T创建通用组件

1 个答案: