angular - 如何在没有 FormBuilder 的情况下在 Angular 2 上推送 FormArray

Question

我有表单数组，我很难解决这个问题。

这是我当前的代码

.ts

ngOnInit() {
    this.item = this.fb.group({
      codeId: ['', Validators.pattern(/^\d+$/)],
      name: ['', [Validators.required, Validators.minLength(3)]],
      stepTextarea: ['', []],
      steps: [this.fb.array([]), []]
    });
}
addProcedure (e): void {
    e.preventDefault();
    const control = <FormGroup>this.item;
    const steps = <FormArray>this.item.controls['steps'];

    steps.push(control.get('stepTextarea').value);
    control.get('stepTextarea').setValue("", {onlySelf: true})
  }

onSubmit({value, valid}: {value: Item, valid: boolean}): void {
    const control = <FormGroup>this.item;
    console.log(value);
}

.html

<ol ngFor [ngForOf]="item.get('steps').controls">
  <span [formGroupName]="i">{{i}}</span>
</ol>

我很难填充和推送。我找不到任何教程。

编辑

提交时我想要这样的东西

{
    codeId: 123,
    name: "wew",
    stepTextarea: "",
    steps: ['asdjlkas','12312','12321']
}

Answer 1

由于您希望步骤在提交时看起来像这样:

steps: ['asdjlkas','12312','12321']

你不应该在步骤中使用 formGroup。

表单的构建应如下所示:

ngOnInit() {
    this.item = this.fb.group({
      codeId: ['', Validators.pattern(/^\d+$/)],
      name: ['', [Validators.required, Validators.minLength(3)]],
      stepTextarea: [''],
      steps: this.fb.array([]) // do not enclose steps inside an array
    });
}

编辑:

这将是您的 addProcedure 的样子:

addStep() {
  const control = <FormArray>this.item.get('steps');
  // push the value from stepTextArea to array
  control.push(this.fb.control(this.item.get('stepTextArea').value))
  // reset
  this.item.get('stepTextArea').reset()
}

你的模板看起来像这样:

<div formArrayName="steps">
<h3>Steps: </h3>
<ol *ngFor="let step of item.get('steps').controls; index as i"> 
   <span>{{step.value}}</span>
</ol>

---

原始答案以及如何执行 FormArray 的解决方案:

addProcedure 应该是这样的:

  addProcedure (e): void {
    const steps = <FormArray>this.item.get('steps');
    steps.push(this.fb.control())
  }

你的 formarray 模板应该是这样的:

<div formArrayName="steps">
  <div *ngFor="let step of item.controls.steps.controls; let i = index" >
      <label>Step {{i+1}} </label>
      <input [formControlName]="i" />
  </div>
</div>