angular - react 形式 Angular 2的多个自定义验证器

Question

我在响应式(Reactive)表单中有两个自定义验证器，我调用下面的函数在组件构造函数中创建表单:

private createForm(): void {
this.passwordUpdateForm = this.formBuilder.group({
    newpassword : [null, Validators.required],
    passwordconfirm: [null, Validators.required]
},
{
    validator: [PasswordValidation.PasswordMatch, PasswordValidation.PasswordRule] // validation method

});

PasswordValidation 是一个具有如下两个函数的类

    export class PasswordValidation {

     public  static PasswordMatch(control: AbstractControl) {
        let password = control.get('newpassword'); // to get value in input tag
        if(password){
            let confirmPassword = control.get('passwordconfirm').value; // to get value in input tag
            if (password.value !== confirmPassword) {
                control.get('passwordconfirm').setErrors({ ['passwordmatch'] : true});
            }else {
                return null;
            }
        }
    }

    public static PasswordRule(control: AbstractControl) {
        let password = control.get('newpassword').value; // to get value in input tag
        let pattern = new RegExp('^(?=.*?[A-Z])(?=.*?[a-z])(?=.*?[0-9])(?=.*?[#?!@$%^&*-]).{8,64}');               
        if (!pattern.test(password)) {
            control.get('newpassword').setErrors({ ['passwordrule'] : true});
        }else if (password.toLowerCase() === 'something') {
            control.get('newpassword').setErrors({ ['passwordrule'] : true});
        }else {
            return null;
        }
    }
}

每个自定义验证器都像这样单独工作

validator: PasswordValidation.PasswordMatch

或者这个

validator: PasswordValidation.PasswordRule

但是像这样在数组中使用它们

validator: [PasswordValidation.PasswordMatch, PasswordValidation.PasswordRule]

得到错误this.validator is not a function并且不起作用，我不知道，请帮助。

Answer 1

最好使用 Validators.compose([])，它接受要在表单组中的特定用户控件上使用的验证器数组。

例如，如果你想为 passwordconfirm 和 newpassword 控件添加验证器，你可以像下面那样做

private createForm(): void {
this.passwordUpdateForm = this.formBuilder.group({
    newpassword : [null, Validators.compose([Validators.required,PasswordValidation.PasswordRule])],
    passwordconfirm: [null, Validators.compose([Validators.required, PasswordValidation.PasswordMatch])]
});

底层代码是这样的

group(controlsConfig: {[key: string]: any}, extra: {[key: string]: any} = null): FormGroup {
  const controls = this._reduceControls(controlsConfig);
  const validator: ValidatorFn = isPresent(extra) ? extra['validator'] : null;
  const asyncValidator: AsyncValidatorFn = isPresent(extra) ? extra['asyncValidator'] : null;
  return new FormGroup(controls, validator, asyncValidator);
}

可以看到参数validator实际上是一种接口(interface)ValidatorFn，如下所示

interface ValidatorFn { 
  (c: AbstractControl): ValidationErrors|null
}

所以你可以看到它可以接受任何具有上述签名的方法。

来源:https://angular.io/api/forms/ValidatorFn

查看此链接了解更多信息:https://toddmotto.com/reactive-formgroup-validation-angular-2