Create a reusable template which can be used on various pages

问题

In my angular 5 application, I need to do this on every HTML page

<span *ngIf="item.createTime; else notAvailable">
   &nbsp;{{item.createdTime | date:'medium'}}
</span>

and on the end of page create that template

<ng-template #notAvailable>
    <span class="text-muted f-12" [innerText]="'N/A'"></span>
</ng-template>

there is repeating the same line of code on every HTML page, so looking for any solution which helps me to create one common component/directive which has only #notAvailable content and can be used on every page with *ngIf?

earlier in angularJS, we can create a separate template file and will be used but in new angular, there is no HTML can be attached in the directive, so a bit confused how to do this?

someone, Please guide me how to achieve this and what need to write in the respective component and HTML?

回答1:

You can create a component ex.: CreatedTimeComponent created-time.component.ts

@Component({
  selector: 'app-created-time',
  templateUrl: './created-time.component.html',
  styleUrls: ['./created-time.component.scss']
})
export class CreatedTimeComponent {
  Input()
  createdTime: Date;
}

created-time.component.html

<ng-container *ngIf="createdTime; else notAvailable">
  <span>
     &nbsp;{{createdTime | date:'medium'}}
  </span>
</ng-container>
<ng-template #notAvailable>
  <span class="text-muted f-12">N/A</span>
</ng-template>

some-other.component.html

<h2>My some other component<h2>
<app-created-time [createdTime]="item.createdTime"></app-created-time>

来源：https://stackoverflow.com/questions/53039918/create-a-reusable-template-which-can-be-used-on-various-pages