Javascript 多个输入字段之间的表单验证

因此，我有一个具有多个输入表单字段的表单和一个嵌套表单组。在嵌套的formgroup中，验证应该是这样的：如果三个输入中的任何一个被填充，那么表单应该是有效的。此人可以填写全部，甚至可以只填写一个，并且表格应有效。我的模板代码如下：

 <h3 class="form-title">{{title}}</h3>
<form [formGroup]="formX" novalidate>
    <div formGroupName="brandIdentifier">
        <mat-form-field class="full-width">
            <mat-icon matSuffix color="primary" *ngIf="brandName.valid && brandName.touched">done</mat-icon>
            <mat-icon matSuffix color="primary" *ngIf="brandName.invalid && brandName.touched">close</mat-icon>
            <input matInput type="text" placeholder="Brand Name" formControlName="brandName" />
        </mat-form-field>
        <mat-form-field class="full-width">
            <mat-icon matSuffix color="primary" *ngIf="brandId.valid && brandId.touched">done</mat-icon>
            <mat-icon matSuffix color="primary" *ngIf="brandId.invalid && brandId.touched">close</mat-icon>
            <input matInput type="text" placeholder="Brand Id" formControlName="brandId" />
        </mat-form-field>
        <mat-form-field class="full-width">
            <mat-icon matSuffix color="primary" *ngIf="contentId.valid && contentId.touched">done</mat-icon>
            <mat-icon matSuffix color="primary" *ngIf="contentId.invalid && contentId.touched">close</mat-icon>
            <input matInput type="text" placeholder="Content Id" formControlName="contentId" />
        </mat-form-field>
    </div>
    <mat-form-field class="full-width">
        <mat-icon matSuffix color="primary" *ngIf="startTime.valid && startTime.touched">done</mat-icon>
        <mat-icon matSuffix color="primary" *ngIf="startTime.invalid && startTime.touched">close</mat-icon>
        <input matInput type="text" placeholder="Start Time" formControlName="startTime" />
    </mat-form-field>
    <mat-form-field class="full-width">
        <mat-icon matSuffix color="primary" *ngIf="endTime.valid && endTime.touched">done</mat-icon>
        <mat-icon matSuffix color="primary" *ngIf="endTime.invalid && endTime.touched">close</mat-icon>
        <input matInput type="text" placeholder="End Time" formControlName="endTime" />
    </mat-form-field>

    <button mat-raised-button color="primary" (click)="startAnalysis()" [ngClass]="{'form-valid':formX.valid, 'form-invalid':formX.invalid}">Submit</button>

    <pre>{{formX.value | json}}</pre>
</form>

this.myForm = this.fb.group({
  nestedGroup: this.fb.group({
    first: [''],
    second: [''],
    third: ['']
    // apply custom validator for the nested group only
  }, {validator: this.myCustomValidator})
});

{{title}
完成
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{{formX.value | json}

---

我该怎么办？使用验证器类是给定的，但我无法将其设置为可选的。

请按照以下步骤操作：

this.myForm = this.fb.group({
  nestedGroup: this.fb.group({
    first: [''],
    second: [''],
    third: ['']
    // apply custom validator for the nested group only
  }, {validator: this.myCustomValidator})
});

注：我们只是想告诉您如何解决您的问题

this.myForm = this.fb.group({
  nestedGroup: this.fb.group({
    first: [''],
    second: [''],
    third: ['']
    // apply custom validator for the nested group only
  }, {validator: this.myCustomValidator})
});

在module.ts中导入FormsModule、ReactiveFormsModule

this.myForm = this.fb.group({
  nestedGroup: this.fb.group({
    first: [''],
    second: [''],
    third: ['']
    // apply custom validator for the nested group only
  }, {validator: this.myCustomValidator})
});

从'@angular/forms'导入{FormsModule，ReactiveFormsModule}

this.myForm = this.fb.group({
  nestedGroup: this.fb.group({
    first: [''],
    second: [''],
    third: ['']
    // apply custom validator for the nested group only
  }, {validator: this.myCustomValidator})
});

@NGD模块({ 导入：[FormsModule，ReactiveFormsModule]}）

this.myForm = this.fb.group({
  nestedGroup: this.fb.group({
    first: [''],
    second: [''],
    third: ['']
    // apply custom validator for the nested group only
  }, {validator: this.myCustomValidator})
});

根据给定内容修改html，例如：

this.myForm = this.fb.group({
  nestedGroup: this.fb.group({
    first: [''],
    second: [''],
    third: ['']
    // apply custom validator for the nested group only
  }, {validator: this.myCustomValidator})
});

用户名 用户名是必需的。 用户名的长度必须至少为4个字符。 密码 密码是必需的。 密码长度必须至少为6个字符。 忘记密码？

this.myForm = this.fb.group({
  nestedGroup: this.fb.group({
    first: [''],
    second: [''],
    third: ['']
    // apply custom validator for the nested group only
  }, {validator: this.myCustomValidator})
});

登录

在[yourcomponent]中修改如下代码。例如：

this.myForm = this.fb.group({
  nestedGroup: this.fb.group({
    first: [''],
    second: [''],
    third: ['']
    // apply custom validator for the nested group only
  }, {validator: this.myCustomValidator})
});

从'@angular/core'导入{Component}； 从“@angular/forms”导入{FormBuilder、FormGroup、Validators}

this.myForm = this.fb.group({
  nestedGroup: this.fb.group({
    first: [''],
    second: [''],
    third: ['']
    // apply custom validator for the nested group only
  }, {validator: this.myCustomValidator})
});

@组成部分({ 选择器：“应用程序登录”， templateUrl:'./login.component.html'， 样式URL:['./login.component.css'] }) 导出类登录组件{

this.myForm = this.fb.group({
  nestedGroup: this.fb.group({
    first: [''],
    second: [''],
    third: ['']
    // apply custom validator for the nested group only
  }, {validator: this.myCustomValidator})
});

loginForm:FormGroup

this.myForm = this.fb.group({
  nestedGroup: this.fb.group({
    first: [''],
    second: [''],
    third: ['']
    // apply custom validator for the nested group only
  }, {validator: this.myCustomValidator})
});

构造函数（私有fb:FormBuilder）{ 此文件名为.loginform（） }

this.myForm = this.fb.group({
  nestedGroup: this.fb.group({
    first: [''],
    second: [''],
    third: ['']
    // apply custom validator for the nested group only
  }, {validator: this.myCustomValidator})
});

get userName（）{返回this.loginForm.get（'userName'）；} get password（）{返回this.loginForm.get（'password'）；}

this.myForm = this.fb.group({
  nestedGroup: this.fb.group({
    first: [''],
    second: [''],
    third: ['']
    // apply custom validator for the nested group only
  }, {validator: this.myCustomValidator})
});

crateLoginForm（）{ this.loginForm=this.fb.group({ 用户名：[''，[Validators.required，Validators.minLength（4）]， 密码：[''[Validators.required，Validators.minLength（6）]] }) }

this.myForm = this.fb.group({
  nestedGroup: this.fb.group({
    first: [''],
    second: [''],
    third: ['']
    // apply custom validator for the nested group only
  }, {validator: this.myCustomValidator})
});

onSubmit（）{ 让userName=this.loginForm.value.userName； 让pwd=this.loginForm.value.password； }

this.myForm = this.fb.group({
  nestedGroup: this.fb.group({
    first: [''],
    second: [''],
    third: ['']
    // apply custom validator for the nested group only
  }, {validator: this.myCustomValidator})
});

}

this.myForm = this.fb.group({
  nestedGroup: this.fb.group({
    first: [''],
    second: [''],
    third: ['']
    // apply custom validator for the nested group only
  }, {validator: this.myCustomValidator})
});

---

您可以为此使用自定义验证器，为嵌套组应用自定义验证器，其中我们检查三个字段中至少有一个字段的值不是空字符串，因此下面是一个示例：

this.myForm = this.fb.group({
  nestedGroup: this.fb.group({
    first: [''],
    second: [''],
    third: ['']
    // apply custom validator for the nested group only
  }, {validator: this.myCustomValidator})
});

构建形式：

this.myForm = this.fb.group({
  nestedGroup: this.fb.group({
    first: [''],
    second: [''],
    third: ['']
    // apply custom validator for the nested group only
  }, {validator: this.myCustomValidator})
});

 myCustomValidator(group: FormGroup) {
   // if true, all fields are empty
   let bool = Object.keys(group.value).every(x => group.value[x] === '')
   if(bool) {
     // return validation error
     return { allEmpty: true}
   }
   // valid
   return null;
 }

自定义验证程序：

this.myForm = this.fb.group({
  nestedGroup: this.fb.group({
    first: [''],
    second: [''],
    third: ['']
    // apply custom validator for the nested group only
  }, {validator: this.myCustomValidator})
});

<small *ngIf="myForm.hasError('allEmpty','nestedGroup')">
  Please fill at least one field
</small>

然后在表单中，您可以通过以下方式显示验证消息：

this.myForm = this.fb.group({
  nestedGroup: this.fb.group({
    first: [''],
    second: [''],
    third: ['']
    // apply custom validator for the nested group only
  }, {validator: this.myCustomValidator})
});

请至少填写一个字段

最后是一个：）

this.myForm = this.fb.group({
  nestedGroup: this.fb.group({
    first: [''],
    second: [''],
    third: ['']
    // apply custom validator for the nested group only
  }, {validator: this.myCustomValidator})
});