如何验证子组件 NgForms 与 Angular4 中的父组件有 3 个不同的 NgForm [英] How to validate the child component NgForms having 3 different NgForm from the parent component in Angular4

问题描述

我有一个场景，我正在访问两个不同的 NgForms，一个在父表单 #parentform 中，另一个在子组件 #childForm & 中.#childForm1，我想检查父组件表单中子表单控件的有效性.如何在 angular4 中做到这一点.

I have a scenario where I am accessing two different NgForms one within Parent form #parentform and other in the Child component #childForm & #childForm1, and i want to check the validity of the controls of child form wether valid or not in parent component form. How to do this in angular4.

我也点击了这个链接:检查表单是否有效从使用 Angular 4 的父组件

每次我都未定义子组件表单的引用时.

everytime i am getting undefined for the reference of child component form.

我的代码是这样的.

parent.component.html

parent.component.html

    <form class="form-wrapper" (ngSubmit)="parentForm.form.valid && save()" #parentForm="ngForm" novalidate>
        <input id="firstName" type="text" placeholder="" class="validate" name="firstName" [(ngModel)]="firstname_" #firstName="ngModel"                         required>
    </form>
    <child-component></child-component>

child.component.html

child.component.html

  <form class="form-wrapper" (ngSubmit)="childForm.form.valid && save()" #childForm="ngForm" novalidate>
            <input id="phoneNumber" type="text" placeholder="" class="validate" name="phoneNumber" [(ngModel)]="phone_" #phoneNumber="ngModel"                       required>
 </form>

 <form class="form-wrapper" (ngSubmit)="childForm1.form.valid && save()" #childForm1="ngForm" novalidate>
            <input id="mobileNumber" type="text" placeholder="" class="validate" name="mobileNumber" [(ngModel)]="mobile_" #mobileNumber="ngModel" required>
 </form>

现在我想验证子组件表单childForm"&childForm1"在父表单中是否有效.

Now i want to validate the child component form "childForm" & "childForm1" valid or not in parent form.

同样在 https://stackblitz.com/edit/angular-cjorjz...

推荐答案

所以你想要的是通过 @Input() 将 parentForm.form.status 传递给孩子.

So what you want, is to pass the parentForm.form.status to the child with an @Input().

在父 html 中:

<child-component [parent]="parentForm.form.status"></child-component>

然后在您的孩子身上:

@Input() parent: any;
private boolean: boolean = false;

ngOnChanges(changes: any) {
  if(changes.dataSet.currentValue === 'VALID'){
    this.boolean = true;
  }
  else { this.boolean = false; }
}

并检查它 console.log(this.boolean) 它或将 {{boolean}} 放在 html 中.或 childForm.form.valid &&保存()&&html 中的布尔值.

And to check it console.log(this.boolean) it or put {{boolean}} in html. Or childForm.form.valid && save() && boolean in html.

编辑

发回验证:

在子组件中，您必须触发 @Output()，因此在 html 上使用更改事件:

In the child component you have to tigger the @Output() so use a change event on the html:

@Output valid: EventEmitter<any> = new EventEmitter<any>();

private checkValid(_childForm: string){
  if(_childForm === 'VALID'){
    this.valid.emit(true);
  }
  else { this.valid.emit(false);
}

在你所有子表单域的 html 中:

In html to all your child formsfield:

(ngModelChange)="checkValid(childForm.form.status)"

在您的父 html 中:

In your parent html:

<child-component [parent]="parentForm.form.status" (valid)="setValidChild($event)"></child-component>

在父组件中:

private childBoolean: boolean= false;

private setValidChild(_boolean: boolean){
  this.childBoolean = _boolean;
}

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