Angular - 如果数组中存在值，则禁用选择选项

Question

我在表单中嵌套了select元素，我只希望每个值选择一次。如何检查occupation.occupation数组中是否存在selectedoccupations并将[disabled]=''设置为true（如果存在）？

成分<​​/ P>

  selectedOccupations: any[] = [
    { occupation: 'dev' },
  ];

模板

<tr>
          <td>
            <md-select formControlName="occupation" [ngModelOptions]="{standalone: true}" placeholder="Occupation" (change)="filterGuests($event, i)">
              <md-option [value]="null">Occupation</md-option>
              <md-option *ngFor="let occupation of occupationz" [value]="occupation.occupation" [disabled]="">
                {{ occupation.occupation }}
              </md-option>
            </md-select>
          </td>
        </tr>

Answer 1

调用typescript函数，为你返回值！

<tr>
  <td>
    <md-select formControlName="occupation" [ngModelOptions]="{standalone: true}" placeholder="Occupation" (change)="filterGuests($event, i)">
      <md-option [value]="null">Occupation</md-option>
      <md-option *ngFor="let occupation of occupationz" [value]="occupation.occupation" [disabled]="isDisabled(occupation)">
        {{ occupation.occupation }}
      </md-option>
    </md-select>
  </td>
</tr>

然后在打字稿中：

function isDisabled(occupation: any):boolean{
    // if it exists... disabled == true;
    return selectedOccupations.includes(occupation.occupation); // note, i'm not certain if this should just be occupation.
}

Answer 2

试试[disabled] = "selectedOccupations.includes(occupation)"？

这不是很有效，但不应该那么糟糕。