如何仅对角度 2+ 中的特定字段应用动态字段验证

Question

我在这里尝试实现动态表单验证，即仅针对特定字段，因为我可以实现动态验证，但我只想为那些我提到名称的字段实现 5 个字段。

说我有像 firstname,lastname,age,gender 这样的字段名称，并且我有一个像 first name,gender 这样的数组现在我想要的是这些字段有数组必须验证不是所有字段我怎么能做到这一点

下面是我的示例代码

**.html**

<div class="jumbotron">
    <div class="container">
        <div class="row">
            <div class="col-md-6 offset-md-3">
                <h2>Angular 6 Reactive Form Validation</h2>
                <form [formGroup]="registerForm" (ngSubmit)="onSubmit()">
                    <div class="form-group">
                        <label>First Name</label>
                        <input type="text" formControlName="firstName" class="form-control" [ngClass]="{ 'is-invalid': submitted && f.firstName.errors }" />
                        <div *ngIf="submitted && f.firstName.errors" class="invalid-feedback">
                            <div *ngIf="f.firstName.errors.required">First Name is required</div>
                        </div>
                    </div>
                    <div class="form-group">
                        <label>Last Name</label>
                        <input type="text" formControlName="lastName" class="form-control" [ngClass]="{ 'is-invalid': submitted && f.lastName.errors }" />
                        <div *ngIf="submitted && f.lastName.errors" class="invalid-feedback">
                            <div *ngIf="f.lastName.errors.required">Last Name is required</div>
                        </div>
                    </div>
                    <div class="form-group">
                        <label>Email</label>
                        <input type="text" formControlName="email" class="form-control" [ngClass]="{ 'is-invalid': submitted && f.email.errors }" />
                        <div *ngIf="submitted && f.email.errors" class="invalid-feedback">
                            <div *ngIf="f.email.errors.required">Email is required</div>
                            <div *ngIf="f.email.errors.email">Email must be a valid email address</div>
                        </div>
                    </div>
                    <div class="form-group">
                        <label>Password</label>
                        <input type="password" formControlName="password" class="form-control" [ngClass]="{ 'is-invalid': submitted && f.password.errors }" />
                        <div *ngIf="submitted && f.password.errors" class="invalid-feedback">
                            <div *ngIf="f.password.errors.required">Password is required</div>
                            <div *ngIf="f.password.errors.minlength">Password must be at least 6 characters</div>
                        </div>
                    </div>
                    <div class="form-group">
                        <button [disabled]="loading" class="btn btn-primary">Register</button>
                    </div>
                </form>
            </div>
        </div>
    </div>
</div>

.ts

import { Component, OnInit } from '@angular/core';
import { FormBuilder, FormGroup, Validators } from '@angular/forms';

@Component({
  selector: 'my-app',
  templateUrl: './app.component.html',
  styleUrls: [ './app.component.css' ]
})
export class AppComponent implements OnInit  {

   registerForm: FormGroup;
    submitted = false;

    constructor(private formBuilder: FormBuilder) { }

    ngOnInit() {
        this.registerForm = this.formBuilder.group({
            firstName: ['', Validators.required],
            lastName: ['', Validators.required],
            email: ['', [Validators.required, Validators.email]],
            password: ['', [Validators.required, Validators.minLength(6)]]
        });
    }

    // convenience getter for easy access to form fields
    get f() { return this.registerForm.controls; }

    onSubmit() {
        this.submitted = true;

        // stop here if form is invalid
        if (this.registerForm.invalid) {
            return;
        }

        alert('SUCCESS!! :-)')
    }
}

我的 Stackblitz 网址

https://stackblitz.com/edit/angular-mbagcm

Answer 1

您可以根据以下条件为字段设置验证器

requiredValids: string[] = ['firstName', 'gender'];

this.registerForm = this.formBuilder.group({
  firstName: ['', this.requiredValids.indexOf('firstName') != -1 ? [Validators.required] : []],
  lastName: ['', this.requiredValids.indexOf('lastName') != -1 ? [Validators.required] : []],
  email: ['', this.requiredValids.indexOf('email') != -1 ? [Validators.required, Validators.email] : []],
  password: ['', this.requiredValids.indexOf('password') != -1 ? [Validators.required, Validators.minLength(6)] : []]
});

工作Stackblitz

Answer 2

this.formBuilder.group({ ABC: new FormArray([]), 

现在。

const abcFormArray = this.formBuilder.controls['ABC'] as FormArray;

Items = [Firstname, Lastname]

Items.forEach(() => {
// do your condition :-
abcFormArray.push((new FormControl(''))
}