Angular2嵌套formGroups-formArrays和模板绑定 [英] Angular2 Nested formGroups - formArrays and template Binding

问题描述

问题出在这里

我有一个带有嵌套表单组的复杂表单，这是它的样子的简化"结构:

I have a complex form with nested formgroups, here is a "simplified" structure of what it looks like :

-> MyForm (formGroup)
    -> Whatever01 (formControl - input)
    -> Whatever02 (formControl - input)
    -> WhateverGroup01 (formGroup)
        -> Whatever03 (formControl - input)
        -> Whatever04 (formControl - input)
    -> WhateverArray01 (formArray)
        -> WhateverGroup02 (formGroup)
            -> Whatever05 (formControl - input)
            -> WhateverGroup03 (formGroup)
                -> Whatever06 (formControl - input)
        -> WhateverGroup04 (formGroup)
            -> Whatever07 (formControl - input)
    -> ...

有角度的一面，应该看起来像这样(不是正确/完整，只是给出一个想法):

Angular side, it should look somehow like this (not correct/complete, but just to give an idea) :

this.myForm = this.fb.group({
    whatever01: ['',Validators.compose([...])],
    whatever02: ['',Validators.compose([...])],
    whateverGroup01: this._formBuilder.group({
        whatever03: ['',Validators.compose([...])],
        whatever04: ['',Validators.compose([...])]
    }),
    whateverArray01: this._formBuilder.array([
        this._formBuilder.group({
            whatever05: ['',Validators.compose([...])],
            whateverGroup03: this._formBuilder.group({
                whatever06: ['',Validators.compose([...])]
            })
        }),
        this._formBuilder.group({
            whatever07: ['',Validators.compose([...])],
        })
    ])
    ...
});

从根myForm项到获取formArray一切都还不错，但是麻烦了....

Things go pretty fine from root myForm item to fetching the formArray, but then come the troubles....

所以，我只是无法访问"whatever05"(而06但05不能工作...所以...)formControl将其绑定到模板！这是模板的实际外观(故意跳过数组之前的部分)，有趣的部分是[????] ="????"，这实际上就是问题所在.

So, I just can't access "whatever05" (and 06 but 05 does NOT work... so...) formControl to bind it to the template ! Here is what the template actually looks like (intentionnaly skipped the part before the array), the interesting part is the [????]="????", this is the problem actually.

<form [formGroup]="myForm" ...>
    <!-- ...skipped... -->
    <div formArrayName="whateverArray01" *ngFor="let item of myForm.controls.whateverGroup01.controls.whateverArray01.controls;let idx = index;" [formGroupName]="idx">
        <div [????]="????">
            <input formControlName="whatever05" ... />
            <div [????]="????">
                <input formControlName="whatever06" ... />
            </div>
        </div>    
    </div>
</form>

位于formArray中的formGroup具有相同的结构.

The formGroups located in the formArray have all the same structure.

基本上，问题是我无法访问formGroups内的formControls

Basically, the problem is that I canNOT access the formControls within the formGroups...

我尝试了几种解决方案，我使用了[formGroupName]，formGroupName(不带括号)，[formGroup]，formControlName等...，但无法弄清楚我必须使用什么方法才能将相应的formGroup/formControl与数据 ！

I tried several solutions, I used [formGroupName] , formGroupName (without brackets), [formGroup], formControlName, ... But cannot figure out what I have to use to be able to bind the corresponding formGroup/formControl with the data !

我现在遇到这种错误:

formGroup expects a FormGroup instance. Please pass one in. 
// This when using [formGroup]="item.whateverGroup02"

Cannot find control with name: 'whatever05'
// When using [formGroup]="item.controls.whateverGroup02"

Cannot find control with path: 'whateverArray01 -> 0 ->'
// This when using [formGroupName]="whateverGroup02"

感谢阅读/帮助

这里有一些代码:

http://plnkr.co/edit/wf7fcHMkhIwzmLWLnCF8?p=preview

推荐答案

首先，您的视图具有错误的绑定:

First of all your view has wrong binding:

[formGroupName]="whateverGroup02"

您的组件中没有whateverGroup02属性.我们应该按如下所示传递字符串:

There is no whateverGroup02 property in your component. We should pass string as follows:

formGroupName="whateverGroup02"

然后，如果您要建立组，例如:

Then if you build group like:

this.fb.group({
  x: 1,
  y: {
    z: 2
  }
})

你会得到

FormGroup
  -> FormControl with name `x` and value `1`   
  -> FormControl with name `y` and value `{ z: 2 }`

这意味着如果要操作嵌套的formGroup，则必须创建它们. 即

It means if you want to manipulate nested formGroups you have to create their. i.e.

let fGroups = data.map(rs => this.buildFormGroup(rs));
...
buildFormGroup(obj) {
  let formGroup: { [id: string]: AbstractControl; } = {};
  Object.keys(obj).forEach(key => {
    formGroup[key] = typeof obj[key] === 'object' ?
      this.buildFormGroup(obj[key]) : 
      new FormControl(obj[key]);
  });
  return this._formBuilder.group(formGroup);
}

柱塞示例

Plunker Example

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