带有参数的Angular 2自定义验证器 [英] Angular 2 custom validator with parameters

问题描述

如何在Angular 2中创建我自己的maxLength验证器? 我可以找到的所有示例都使用类似于必需"的验证器，这意味着他们已经知道规则.他们只接受一个参数-控件本身.如何传递更多参数?

How do I create let's say my own maxLength validator in Angular 2? All examples I could find use validators similar to 'required' one meaning that they already know the rules. They only accept one param - the control itself. How do I pass more parameters?

这是我的示例验证器.如何修改它以将数字5传递为参数?

Here's the sample validator I have. How do I modify it to pass number 5 as a parameter?

export class MyValidators {
    static minValue(control:Control): {[s: string]: boolean} {
        var num = +control.value;
        if (isNaN(num) || num < 5 ) { return {"minValue": true}; }
        return null;
    }
}

推荐答案

这里是一个示例.这是一个最小值验证器，您可以在其中传递一个数字进行验证.

Here is a sample. It's a min value validator where you pass in a number to validate.

import {Control} from 'angular2/common';

export const minValueValidator = (min:number) => {
  return (control:Control) => {
    var num = +control.value;
    if(isNaN(num) || num < min){
      return {
         minValue: {valid: false}
      };
    }
    return null;
  };
};

更多详细信息可以在自定义验证程序官方文档页面中找到.

More details can be found in the Custom Validators official documentation page.

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