Question

我正在写一个angular2验证器指令。我有以下情况：

有一个数字A，而且有一个数字B，我需要验证B字段中的数字是否小于或等于A字段中的数字，我使用的是模板驱动表格。

指令中的代码是

import { Directive, Input, OnChanges, SimpleChanges } from '@angular/core';
import { AbstractControl, NG_VALIDATORS, Validator, ValidatorFn, Validators } from '@angular/forms';

export function validateLesserOrEqual(number: number): ValidatorFn {
  console.log(number);
  return (c: AbstractControl) => {
    return c.value <= number ? null : {
      validateLesserOrEqual: {
        valid: false
      }
    }
  }
}

@Directive({
  selector: '[lesserOrEqual][ngModel]'
})
export class LesserOrEqualValidator implements Validator, OnChanges {
  @Input() lesserOrEqualInput: number;
  private _validator = Validators.nullValidator;

  ngOnChanges(changes: SimpleChanges) {
    const change = changes['lesserOrEqual'];
    if(change) {
      const val: number = change.currentValue;
      this._validator = validateLesserOrEqual(val);
    }
    else {
      this._validator = Validators.nullValidator;
    }
  }

  validate(c: AbstractControl): {[number: number]: any} {
    return this._validator(c);
  }
}

在我的输入中我有以下[lesserOrEqual]="movement.parcel_number"，但是当我把方括号括在指令周围时，我得到了以下错误Unhandled Promise rejection: Template parse errors: Can't bind to 'lesserOrEqual' since it isn't a known property of 'input'. ("dirty}"

Angular2 min指令验证器

0 个答案: