当只有一个条件为真时，两个 mat-error 都会显示 [英] Both mat-error show when only one condition is true

问题描述

当只出现一个错误时，两个 mat-error 都会显示.

Both mat-error show when only one error appeared.

我正在尝试使用 mat-error 制作自定义验证器.当电子邮件和确认密码的输入都为 hasError('') 的真值时，它们都是红色的.

I'm trying to make custom validators with mat-error. Both input for email and confirm password are red when each of them has a true value for hasError('').

我认为我的 MyErrorStateMatcher 类逻辑不知何故是错误的.请帮忙！我已经尝试了任何我能做的.提前致谢！

I think my MyErrorStateMatcher class logic is wrong somehow. Please help! I have tried anything I could. Thank you in advance!

图片

正如您在图像中看到的那样.当confirmPassword 抛出错误时，email 字段也是红色的.

As you can see in the image. When confirmPassword throws an error, the email field is also red.

我的 ErrorStateMatcher:

My ErrorStateMatcher:

export class MyErrorStateMatcher implements ErrorStateMatcher {
  isErrorState(control: FormControl | null, form: FormGroupDirective | NgForm | null): boolean {
    const invalidCtrl = !!(control && control.invalid && (control.dirty || control.touched));
    const invalidParent = !!(control && (control.parent.hasError('notTheSame') || control.parent.hasError('emailUsed')));

    return ((invalidCtrl || invalidParent));
  }
}

HTML:(关注 email 和 confimPassword)

HTML: (focus on email and confimPassword)

<form [formGroup]="signupForm" (ngSubmit)="signup(signupForm)">
        <mat-form-field style="width: 100%;">
          <input matInput formControlName="email" placeholder="Email address" type="email" [errorStateMatcher]="matcher" required>
          <mat-error *ngIf="signupForm.controls.email.hasError('required')">Email required!</mat-error>
          <mat-error *ngIf="signupForm.controls.email.hasError('email')">Email invalid!</mat-error>
          <mat-error *ngIf="signupForm.hasError('emailUsed')">This email already exists!</mat-error>
        </mat-form-field>
        <mat-form-field style="width: 100%;">
          <input matInput formControlName="username" placeholder="User name" (blur)="signupForm.value.username != null ? isValidUsername(signupForm.value.username) : ''" required />
          <mat-error>Please enter your new username!</mat-error>
          <mat-error *ngIf="usernameInvalid">Username already exists!</mat-error>
        </mat-form-field>
        <mat-form-field style="width: 100%;">
          <input matInput formControlName="password" placeholder="New password" [type]="show ? 'text' : 'password'" required />
          <mat-icon matSuffix (click)="show = !show" style="cursor: pointer;">{{show ? 'visibility' : 'visibility_off'}}</mat-icon>
          <mat-error>Please enter your password!</mat-error>
        </mat-form-field>
        <mat-form-field style="width: 100%;">
          <input matInput formControlName="confirmPassword" placeholder="Confirm password" type="password" [errorStateMatcher]="matcher" required>
          <mat-error *ngIf="signupForm.controls.confirmPassword.hasError('required')">Please confirm your password!</mat-error>
          <mat-error *ngIf="signupForm.hasError('notTheSame') && signupForm.value.confirmPassword != ''">Password is not the same!</mat-error>
        </mat-form-field>
        <br>
      <button mat-raised-button class="sessionBtn" color="primary" [disabled]="signupForm.invalid">Submit!</button>
</form>

TS:

signupForm = new FormGroup({
    firstName: new FormControl(),
    lastName: new FormControl(),
    email: new FormControl('', [
      Validators.required,
      Validators.email
    ]),
    username: new FormControl(),
    password: new FormControl('', [
      Validators.required
    ]),
    confirmPassword: new FormControl('', [
      Validators.required
    ])
  }, { validators: [this.checkPassword, this.checkExistingEmail] });
  matcher = new MyErrorStateMatcher();

/////////Custom validator////////

  checkPassword(signupForm: FormGroup) {
    let password = signupForm.value.password;
    let confirmPassword = signupForm.value.confirmPassword;

    return password === confirmPassword ? null : { notTheSame: true };
  }

  checkExistingEmail(signupForm: FormGroup) {
    let inputEmail = signupForm.value.email;
    let dbEmail = "[e-mail]";

    return inputEmail !== dbEmail ? null: { emailUsed: true };
  }

输入电子邮件和输入确认密码时出错，两者都有 [errorStateMatcher]="matcher"

Error happend with input email and input confirmPassword, both have [errorStateMatcher]="matcher"

推荐答案

创建 customErrorMatcher

Creating a customErrorMatcher

好吧，如果我们想在 input 是 valid 时在 中显示错误，我们使用自定义ErrorMatcher.

Well, if we want to show an error in a <mat-form-field> when the input is valid, we use a customErrorMatcher.

这是一个类

class CrossFieldErrorMatcher implements ErrorStateMatcher {
  isErrorState(control: FormControl | null, form: FormGroupDirective | NgForm | null): boolean {
    //when we want to show the error
    return true 
    //when we want not show the error
    return false
  }
}

通常我们的组件中有

  errorMatcher=new CrossFieldErrorMatcher()
  //and the .html
  <mat-form-field>
    <input matInput formControlName='verifyPassword' 
        [errorStateMatcher]="errorMatcher">
    <mat-error *ngIf="....">
      Passwords do not match!
    </mat-error>
  </mat-form-field>

好吧，我们稍微改变一下，在 customErrorMatcher 中添加一个构造函数

Well, we are change the things a bit, adding a constructor in our customErrorMatcher

class CrossFieldErrorMatcher implements ErrorStateMatcher {
  constructor(private name:string){}  //<--add a constructor
  isErrorState(control: FormControl | null, form: FormGroupDirective | NgForm | null): boolean {
    //when we want to show the error, but we can use "name"
    return true 
    //when we want not show the error
    return false
  }
}

然后，我们的组件就变成了

Then, our component becomes

  errorMatcher(name:string)
  {
    return new CrossFieldErrorMatcher(name);
  }

  //and the .html
  <mat-form-field>
    <input matInput formControlName='verifyPassword' 
        [errorStateMatcher]="errorMatcher('password')">
    <mat-error *ngIf="....">
      Passwords do not match!
    </mat-error>
  </mat-form-field>

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