在反应式表单中，如何创建一个自定义验证器来验证没有值的formGroup数组？

import { FormGroup, ValidatorFn, ValidationErrors } from '@angular/forms';

export function customValidator(): ValidatorFn {
  return (formGroup: FormGroup): ValidationErrors | null => {
    const controls = formGroup.controls;

    // 检查formGroup数组是否有值
    const hasValue = Object.values(controls).some(control => control.value !== null && control.value !== '');

    // 如果没有值，则返回验证失败的结果
    if (!hasValue) {
      return { 'noValue': true };
    }

    return null; // 验证通过
  };
}

import { Component } from '@angular/core';
import { FormBuilder, FormGroup, Validators } from '@angular/forms';
import { customValidator } from './custom-validator';

@Component({
  selector: 'app-form',
  template: `
    <form [formGroup]="myForm">
      <div formArrayName="myArray">
        <div *ngFor="let control of myArray.controls; let i = index">
          <input [formControlName]="i" placeholder="Value {{ i + 1 }}">
        </div>
      </div>
      <button (click)="submit()">Submit</button>
    </form>
  `,
})
export class FormComponent {
  myForm: FormGroup;

  constructor(private fb: FormBuilder) {
    this.myForm = this.fb.group({
      myArray: this.fb.array([], customValidator()) // 应用自定义验证器
    });
  }

  get myArray() {
    return this.myForm.get('myArray') as FormArray;
  }

  submit() {
    if (this.myForm.valid) {
      // 执行提交操作
    } else {
      // 表单验证失败
    }
  }
}