Nested Form Groups & FromArray in Angular 8 - angular8

Question

I working on form which has nested form groups & form arrays but I am not able to bind values in ts.
I am new to angular so dont have much clarity on formgroup and form arrays.
below json can have multiple arrays within formgroups and nested form arrays within form group.
Here is the sample example which i want to execute and make below json structure from this form
Json using this form :
{
ip:'1.2.3.4',
create_adjacency:{
customerName:'ABC',
traffic_group:[{
_display_name:'DEF',
traffic_group_limits:{
calls:'23' }
}]
}
}
HTML -
<div class="page-container pb-25 ">
<form [formGroup]="firstFormGroup">
<div class="form-group custom-input select-custom-prime">
<label>IP</label>
<input
placeholder="Select"
formControlName="ip"
/>
</div>
<div class="row mb-20" formGroupName="create_adjacency">
<div class="col-xl-4 col-lg-6 col-md-6">
<div
class="form-group custom-input select-custom-prime"
>
<label>Customer Name</label>
<input
placeholder="Select"
formControlName="customerName"
/>
</div>
</div>
<div formArrayName="traffic_group">
<div class="col-xl-3 col-lg-6 col-md-6">
<div
class="form-group custom-input mr-10 select-custom-prime" >
<label>Traffic group Name</label>
<input
formControlName="_display_name"
/>
</div>
</div>
<table
class="mt-30 table table-striped table-bordered wd-98"
>
<thead>
<tr>
<th>Traffic Group Name</th>
<th>Concurrent Calls</th>
</tr>
</thead>
<tbody formGroupName="traffic_group_limits">
<tr>
<td>
<div class="">
<div
class="form-group custom-input select-custom-prime"
>
<input
pInputText
autofocus
disabled
type="text"
class="form-control"
/>
</div>
</div>
</td>
<td>
<div class="">
<div
class="form-group custom-input select-custom-prime"
>
<input
formControlName="calls"
pInputText
autofocus
class="form-control"
/>
</div>
</div>
</td>
</tr>
</tbody>
</table>
</div>
</div>
</form>
</div>
Ts code -
this.firstFormGroup = this.formBuilder.group({
ip: [''],
create_adjacency: this.formBuilder.group({
customerName: ["", Validators.required],
traffic_groups: this.formBuilder.array([this.traffic_groups])
})
});
get traffic_groups(): FormGroup {
return this.formBuilder.group({
_display_name: ["", Validators.required],
traffic_group_limits: this.formBuilder.group({
"call-appearances": ["", Validators.required]
})
});
}

Answer 1

In my opinion, as much angular has their own way of doing this, it might be a little intimidating to a beginner. So I prefer breaking down the formgroups and then constructing the final json from all the forms all together.
.html
<div class="page-container pb-25 ">
<form [formGroup]="firstFormGroup">
<div class="form-group custom-input select-custom-prime">
<label>IP</label>
<input
placeholder="Select"
formControlName="ip"
/>
</div>
<div class="row mb-20" [formGroup]="adjacencyFormGroup">
<div class="col-xl-4 col-lg-6 col-md-6">
<div
class="form-group custom-input select-custom-prime"
>
<label>Customer Name</label>
<input
placeholder="Select"
formControlName="customerName"
/>
</div>
</div>
<div [formGroup]="trafficFormGroup">
<div class="col-xl-3 col-lg-6 col-md-6">
<div
class="form-group custom-input mr-10 select-custom-prime" >
<label>Traffic group Name</label>
<input
formControlName="_display_name"
/>
</div>
</div>
<table
class="mt-30 table table-striped table-bordered wd-98"
>
<thead>
<tr>
<th>Traffic Group Name</th>
<th>Concurrent Calls</th>
</tr>
</thead>
<tbody [formGroup]="trafficGroupLimit">
<tr>
<td>
<div class="">
<div
class="form-group custom-input select-custom-prime"
>
<input
pInputText
autofocus
disabled
type="text"
class="form-control"
/>
</div>
</div>
</td>
<td>
<div class="">
<div
class="form-group custom-input select-custom-prime"
>
<input
formControlName="calls"
pInputText
autofocus
class="form-control"
/>
</div>
</div>
</td>
</tr>
</tbody>
</table>
</div>
</div>
</form>
</div>
.ts
this.firstFormGroup = this.formBuilder.group({
ip: [''],
create_adjacency: [{}]
});
this.adjacencyFormGroup = this.formBuilder.group({
customerName: ["", Validators.required],
traffic_groups: [[]])
});
this.trafficFormGroup = this.formBuilder.group({
_display_name: ["", Validators.required],
traffic_group_limits: [{}]
});
this.trafficGroupLimit = this.formBuilder.group({
calls: [''],
});
function to create json
createFormJSON() {
this.trafficFormGroup.patchValue({
traffic_group_limits: this.trafficGroupLimit.value
});
this.adjacencyFormGroup.patchValue({
traffic_groups: this.allTrafficGroups // store all traffic groups in this array before patching
});
this.firstFormGroup.patchValue({
create_adjacency: this.adjacencyFormGroup.value,
});
}