Angular 2 – 反应式表单验证消息

我的目标是将所有验证消息放在组件而不是html文件

我有一个注册页面,下面是字段:

public buildRegisterForm() {
this.userForm = this.fb.group({
  firstName: ['',[Validators.required,Validators.minLength(3)]],lastName: ['',Validators.maxLength(50)]],emailGroup: this.fb.group({
    email: ['',Validators.pattern(this.emailPattern)]],retypeEmail: ['',Validators.required],},{ validator: formMatcherValidator('email','retypeEmail') }),passwordGroup: this.fb.group({
    password: ['',strongPasswordValidator()]],retypePassword: ['',{ validator: formMatcherValidator('password','retypePassword')}),});
}

我正在按照本教程link来实现我想要的东西
将所有验证消息放在组件文件中而不是html文件中.

export const validationMessages = {
'firstName': {
'required': 'Your first name is required.','minlength': 'Your first name must be at least 3 characters long.'
},'lastName': {
'required': 'Your last name is required.','minlength': 'Your last name must be less than 50 characters long.'
},'emailGroup': {
  'email': {
      'required': 'Your email is required','pattern': 'Your login email does not seem to be a valid email address.'
     },'retypeEmail': {
      'required': 'Your retype email is required','match': 'The email provided do not match.'
   },'passwordGroup':{
     'password': {
         'required': 'Your password is required','strongPassword': 'Your password must be between 8 - 15 characters and must contain at least three of the following: upper case letter,lower case letter,number,symbol.'
     },'retypePassword': {
       'required': 'Your retype password is required','match': 'The password provided do not match.'
  }
}

onValueChanged方法

private onValueChanged(data?: any) {
if (!this.userForm) { return; }
const form = this.userForm;

// tslint:disable-next-line:forin
for (const field in this.formErrors) {
  // clear prevIoUs error message (if any)
  this.formErrors[field] = '';
  let control = form.get(field);
  // console.log("control",control.dirty);

  console.log("controlEmail",control);
  if (control && (control.dirty || control.touched) && control.invalid) {
    let messages = validationMessages[field];
    // tslint:disable-next-line:forin
    for (const key in control.errors) {
      this.formErrors[field] += messages[key] + ' ';
    }
  }
 }
}

当我有多个formBuider组或嵌套对象时,此方法不起作用.这1的任何提示
类似于这个How to validate reactive forms with nested form groups?

我看到它的方式,你需要在onValueChanged(data)-method中创建一个嵌套循环.由于你有很多嵌套组,我不打算复制它.但嵌套循环是通用的,因此它适用于所有组.但这是一个只有一个嵌套组而不是几个嵌套组的例子.我正在使用英雄的例子.

嵌套组名称是group,其中的formcontrol称为child.

因此,代码中使用的formErrors应该具有内部组中的子项:

formErrors = {
  'name': '','power': '','group':{
    'child': ''
  }
};

因此,您必须记住在模板中添加验证时,您需要使用:

<div *ngIf="formErrors.group.child">
   {{ formErrors.group.child }}
</div>

验证消息不在组内,但与其他验证消息一样:

validationMessages = {
  'name': {
    'required': 'Name is required.','power': {
    'required': 'Power is required.'
  },'child': {
    'required': 'Child is required.',}
};

最后,修改后的onValueChanges:

onValueChanged(data?: any) {
  if (!this.heroForm) { return; }
  const form = this.heroForm;

  // iterate toplevel of formErrors
  for (const field in this.formErrors) {
    // check if the field corresponds a formgroup (controls is present)
    if(form.get(field).controls ) {
      // if yes,iterate the inner formfields
      for(const subfield in form.get(field).controls) {
        // in this example corresponds = "child",reset the error messages
        this.formErrors[field][subfield] = '';
        // now access the actual formfield
        const control = form.get(field).controls[subfield];
        // validate and show appropriate error message
        if (control && control.dirty && !control.valid) {
          const messages = this.validationMessages[subfield];
          for (const key in control.errors) {
            this.formErrors[field][subfield] += messages[key] + ' ';
          }
        }
      }
    } 
    // does not contain a nested formgroup,so just iterate like before making changes to this method
    else {
      const control = form.get(field);
      this.formErrors[field] = '';
      if (control && control.dirty && !control.valid) {
        const messages = this.validationMessages[field];
        for (const key in control.errors) {
          this.formErrors[field] += messages[key] + ' ';
        }
      } 
    }
  }
}

最后,一个DEMO

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