angular - 输入时 FormControl 不更新

Question

我有一个使用自定义组件作为输入的表单，它接收一个 ControlName。当我在组件中键入内容时，它不会更新“错误”属性。

app-pf-input-text.ts:

import { Component, OnInit, Input } from '@angular/core';

@Component({
  selector: 'app-pf-input-text',
  templateUrl: './pf-input-text.component.html',
  styleUrls: ['./pf-input-text.component.scss']
})
export class PfInputTextComponent implements OnInit {

  @Input() id: string;
  @Input() name: string;
  @Input() value: string;
  @Input() placeholder: string;

  //falta trim

  @Input() maxlength: string;
  @Input() minlength: string;

  @Input() disabled: boolean;
  @Input() required: boolean;

  constructor() { }

  ngOnInit() {
  }
}

app-pf-input-text.html:

<div class="input-group">
  <input 
      type="text" class="form-control">
</div>

我的表单:

import { Component, OnInit, Input } from '@angular/core';

import { FormArray, FormBuilder, FormGroup, Validators, FormControl } from '@angular/forms';

import { Empresa } from '../empresa.model';

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

  empresaForm: FormGroup;

  nomeControl: FormControl;

  constructor(private fb: FormBuilder) {}

  createForm() {
    this.nomeControl = new FormControl('', [
      Validators.required,
      Validators.minLength(3),
      Validators.maxLength(10)
    ]);
  }

  createFormControl() {
    console.log('Criando FormControl');
  }

  onSubmit() {
    const empresa = this.empresaForm.value as Empresa;
    console.log('Empresa: ', empresa);
  }

  limpar() {
    this.empresaForm.reset();
  }

  ngOnInit() {
    this.createForm();
  }

}

我的表单 html:

<form [formGroup]="empresaForm">
  <div class="form-row">


    <div class="col-md-4 mb-3">
      <label for="validationServer01">Nome empresa</label>
      <app-pf-input-text controlName="nome"></app-pf-input-text>
      {{nomeControl.errors | json}} - {{nomeControl.dirty}}
      <div class="form-control-feedback" *ngIf="nomeControl.errors && (nomeControl.dirty || nomeControl.touched)">
        <div *ngIf="nomeControl.errors.required" class="has-error">
          Campo obrigatorio
        </div>
        <div *ngIf="nomeControl.errors.maxlength">
          Campo ultrapassou o tamanho maximo.
        </div>
        <div *ngIf="nomeControl.errors.minlength">
          Campo não antingiu o tamanho minimo
        </div>
      </div>
    </div>


  </div>
</form>

它在“ControlName”中提供了一个初始值，但在我输入时它永远不会更新。

{{nomeControl.errors | json}} - {{nomeControl.dirty}}

返回:

{ “必需”:真 } - 假

当您在输入中输入内容时，这些值不会更新。

Answer 1

您正在混合响应式(Reactive)和模板驱动的形式。你的PfInputTextComponent有一些问题。使用 Reactive Forms，您不需要 required , maxLength , minLength和 disabled输入。你确实需要 FormControl输入。如果您使用的是 Reactive Forms，则可以在组件类中设置值和验证器，而不是在模板中。

this.nomeControl = new FormControl('', [
  Validators.required,
  Validators.minLength(3),
  Validators.maxLength(10)
]);

这足以设置验证和初始值。您现在需要做的就是将此控件绑定(bind)到您的 html <input />使用 [formControl]指令。

app-pf-input-text.html

<div class="input-group">
  <input [formControl]="ctrl" type="text" class="form-control">
</div>

app-pf-input-text.ts:

import { Component, OnInit, Input } from '@angular/core';
import { FormControl } from '@angular/forms';

@Component({
  selector: 'app-pf-input-text',
  templateUrl: './pf-input-text.component.html',
  styleUrls: ['./pf-input-text.component.scss']
})
export class PfInputTextComponent implements OnInit {

  @Input() ctrl: FormControl;
  @Input() placeholder: string;

  constructor() {}

  ngOnInit() {}
}

form.component.html

<app-pf-input-text [ctrl]="nomeControl"></app-pf-input-text>