Question

我想为angular2进行自定义验证。此验证必须访问表单的另一个组件。这可能吗？

我的模板

<input type="tekst" id="startDate" name="startDate" [(ngModel)]="model.startDate" #startDate="ngModel" >

<input type="tekst" id="endDate" name="endDate" [(ngModel)]="model.endDate" #endDate="ngModel" customValidator>

我的验证员

...
@Directive({
    selector: '[customValidator][ngModel][customValidator][formControl]',
    providers: [
        provide : NG_VALIDATORS,
        useExisting : forwardRef(() = > CustomValidator),
        Multi : true
    }]
})

export class CustomValidator impelments Validator {
    constructor(){}

    validate(c : FormControl) : {[key : string] : any} {

        // HOW TO ACCESS startDate CONTROL HERE? OR ITS VALUE? OR THE MODEL
    }

Answer 1

如果要实现交叉验证，则应将验证移至祖先控件。

然后您的验证方法如下所示：

validate(fg: FormGroup) {
  const start = fg.get('startDate').value;
  const end = fg.get('enDate').value;

  return start !== null && end !== null && start < end 
   ? null 
   : { range: true };
};

详细了解交叉验证here。

Answer 2

你可以喜欢

@Directive({
    selector: '[customValidator][ngModel][customValidator][formControl]',
    providers: [
        provide : NG_VALIDATORS,
        useExisting : forwardRef(() = > CustomValidator),
        Multi : true
    }]
})

export class CustomValidator impelments Validator {
    constructor(){}

    validate(c : FormControl) : {[key : string] : any} {
         let control_value= c.value;
        // HOW TO ACCESS startDate CONTROL HERE? OR ITS VALUE? OR THE MODEL
    }

另请参阅此链接：custom validator和custom validtor with reverse match

自定义验证访问表单组件

2 个答案: