我正在处理登录表单,如果用户输入无效凭据,我们希望将电子邮件和密码字段都标记为无效,并显示登录失败的消息。我如何从一个可观察的回调设置这些字段无效?

模板:

<form #loginForm="ngForm" (ngSubmit)="login(loginForm)" id="loginForm">
  <div class="login-content" fxLayout="column" fxLayoutAlign="start stretch">
    <md-input-container>
      <input mdInput placeholder="Email" type="email" name="email" required [(ngModel)]="email">
    </md-input-container>
    <md-input-container>
      <input mdInput placeholder="Password" type="password" name="password" required [(ngModel)]="password">
    </md-input-container>
    <p class='error' *ngIf='loginFailed'>The email address or password is invalid.</p>
    <div class="extra-options" fxLayout="row" fxLayoutAlign="space-between center">
     <md-checkbox class="remember-me">Remember Me</md-checkbox>
      <a class="forgot-password" routerLink='/forgot-password'>Forgot Password?</a>
    </div>
    <button class="login-button" md-raised-button [disabled]="!loginForm.valid">SIGN IN</button>
     <p class="note">Don't have an account?<br/> <a [routerLink]="['/register']">Click here to create one</a></p>
   </div>
 </form>

登录方法:

 @ViewChild('loginForm') loginForm: HTMLFormElement;

 private login(formData: any): void {
    this.authService.login(formData).subscribe(res => {
      alert(`Congrats, you have logged in. We don't have anywhere to send you right now though, but congrats regardless!`);
    }, error => {
      this.loginFailed = true; // This displays the error message, I don't really like this, but that's another issue.
      this.loginForm.controls.email.invalid = true;
      this.loginForm.controls.password.invalid = true; 
    });
  }

除了将输入无效标志设置为true之外,我还尝试设置电子邮件。valid标志为false,并设置loginForm。无效也为真。这些都不会导致输入显示其无效状态。


当前回答

在我的反应式形式,我需要标记一个字段无效,如果另一个字段被选中。在ng版本7中,我做了以下工作:

    const checkboxField = this.form.get('<name of field>');
    const dropDownField = this.form.get('<name of field>');

    this.checkboxField$ = checkboxField.valueChanges
        .subscribe((checked: boolean) => {
            if(checked) {
                dropDownField.setValidators(Validators.required);
                dropDownField.setErrors({ required: true });
                dropDownField.markAsDirty();
            } else {
                dropDownField.clearValidators();
                dropDownField.markAsPristine();
            }
        });

所以在上面,当我选中这个框时,它会根据需要设置下拉框,并将其标记为脏。如果您不这样标记它,那么直到您尝试提交表单或与之交互时,它才会无效(错误)。

如果复选框被设置为false(未选中),那么我们清除下拉菜单上所需的验证器,并将其重置为原始状态。

另外,记得取消订阅监控字段更改!

其他回答

在material 2的新版本中,它的控件名称以mat前缀setErrors()开始不起作用,相反,Juila的答案可以更改为:

formData.form.controls['email'].markAsTouched();

你也可以将viewChild的“类型”更改为NgForm,如下所示:

@ViewChild('loginForm') loginForm: NgForm;

然后以@Julia提到的相同方式引用控件:

 private login(formData: any): void {
    this.authService.login(formData).subscribe(res => {
      alert(`Congrats, you have logged in. We don't have anywhere to send you right now though, but congrats regardless!`);
    }, error => {
      this.loginFailed = true; // This displays the error message, I don't really like this, but that's another issue.

      this.loginForm.controls['email'].setErrors({ 'incorrect': true});
      this.loginForm.controls['password'].setErrors({ 'incorrect': true});
    });
  }

将Errors设置为null将清除UI上的错误:

this.loginForm.controls['email'].setErrors(null);

在我的反应式形式,我需要标记一个字段无效,如果另一个字段被选中。在ng版本7中,我做了以下工作:

    const checkboxField = this.form.get('<name of field>');
    const dropDownField = this.form.get('<name of field>');

    this.checkboxField$ = checkboxField.valueChanges
        .subscribe((checked: boolean) => {
            if(checked) {
                dropDownField.setValidators(Validators.required);
                dropDownField.setErrors({ required: true });
                dropDownField.markAsDirty();
            } else {
                dropDownField.clearValidators();
                dropDownField.markAsPristine();
            }
        });

所以在上面,当我选中这个框时,它会根据需要设置下拉框,并将其标记为脏。如果您不这样标记它,那么直到您尝试提交表单或与之交互时,它才会无效(错误)。

如果复选框被设置为false(未选中),那么我们清除下拉菜单上所需的验证器,并将其重置为原始状态。

另外,记得取消订阅监控字段更改!

我试图在模板形式的ngModelChange处理程序中调用setErrors()。它没有工作,直到我用setTimeout()等待一个滴答:

模板:

<input type="password" [(ngModel)]="user.password" class="form-control" 
 id="password" name="password" required (ngModelChange)="checkPasswords()">

<input type="password" [(ngModel)]="pwConfirm" class="form-control"
 id="pwConfirm" name="pwConfirm" required (ngModelChange)="checkPasswords()"
 #pwConfirmModel="ngModel">

<div [hidden]="pwConfirmModel.valid || pwConfirmModel.pristine" class="alert-danger">
   Passwords do not match
</div>

组件:

@ViewChild('pwConfirmModel') pwConfirmModel: NgModel;

checkPasswords() {
  if (this.pwConfirm.length >= this.user.password.length &&
      this.pwConfirm !== this.user.password) {
    console.log('passwords do not match');
    // setErrors() must be called after change detection runs
    setTimeout(() => this.pwConfirmModel.control.setErrors({'nomatch': true}) );
  } else {
    // to clear the error, we don't have to wait
    this.pwConfirmModel.control.setErrors(null);
  }
}

像这样的陷阱让我更喜欢反应式。

下面是一个有效的例子:

MatchPassword(AC: FormControl) {
  let dataForm = AC.parent;
  if(!dataForm) return null;

  var newPasswordRepeat = dataForm.get('newPasswordRepeat');
  let password = dataForm.get('newPassword').value;
  let confirmPassword = newPasswordRepeat.value;

  if(password != confirmPassword) {
    /* for newPasswordRepeat from current field "newPassword" */
    dataForm.controls["newPasswordRepeat"].setErrors( {MatchPassword: true} );
    if( newPasswordRepeat == AC ) {
      /* for current field "newPasswordRepeat" */
      return {newPasswordRepeat: {MatchPassword: true} };
    }
  } else {
    dataForm.controls["newPasswordRepeat"].setErrors( null );
  }
  return null;
}

createForm() {
  this.dataForm = this.fb.group({
    password: [ "", Validators.required ],
    newPassword: [ "", [ Validators.required, Validators.minLength(6), this.MatchPassword] ],
    newPasswordRepeat: [ "", [Validators.required, this.MatchPassword] ]
  });
}