How do I clear the FormArray in Angular Reactive Forms

Question

I am doing resetting of form. It resets the whole form but except FormArray.

Creating the form and declaring formArray within it

createForm(){
    this.invoiceForm = this.formBuilder.group({
      'name': ['', Validators.required],
      'gst': [''],
      'currency': [''],
      'addressLine1': ['', Validators.required],
      'addressLine2': [''],
      'city': ['', Validators.required],
      'state': ['', Validators.required],
      'country': ['', Validators.required],
      'postalCode': ['', Validators.required],
      'email': ['', [Validators.required, Validators.email]],
      'invoiceparticulars': this.formBuilder.array([]),
      'isGstshidden' : true
    });

  }

Trying to modify details of the form from the incoming data by resetting the data even though I called reset() function formArray retaining previous entries in it.

 modifyInvoice(index){

   this.invoiceForm.reset();

   let modifyData = this.modifyInvoiceArray[index];
   console.log(modifyData);

   this.invoiceNumber = modifyData.invoiceNumber;
   this.invoiceForm.patchValue({name: modifyData.address.Name});
   this.invoiceForm.patchValue({email: modifyData.email});
   this.invoiceForm.patchValue({gst: modifyData.GSTnumber});
   this.invoiceForm.patchValue({addressLine1: modifyData.address.AddressLine1});
   this.invoiceForm.patchValue({addressLine2: modifyData.address.AddressLine2});
   this.invoiceForm.patchValue({city: modifyData.address.City});
   this.invoiceForm.patchValue({country: modifyData.address.Country});
   this.invoiceForm.patchValue({postalCode: modifyData.address.PostalCode});
   this.invoiceForm.patchValue({state: modifyData.address.State});
   console.log(modifyData['particulars']);
}

MajiD · Answer 1 · 2020-05-10T07:24:44.347

19

Angular 8

simply use clear() method on formArrays :

(this.invoiceForm.controls['invoiceparticulars']).clear();

OR :

let frmArray = this.invoiceForm.get('invoiceparticulars') as FormArray;
frmArray.clear();

edited May 10 '20 at 07:24

answered Jul 31 '19 at 21:17

MajiD

1,880
1
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29

score 3 · Accepted Answer · answered May 07 '18 at 02:44

3

Try to add this code

const control = <FormArray>this.invoiceForm.controls['invoiceparticulars'];
        for(let i = control.length-1; i >= 0; i--) {
            control.removeAt(i)
    }

answered May 07 '18 at 02:44

Joseph

4,309
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rather than this I can even directly call this.createForm(); which resets the form right?! – Dhaanappagouda Patil May 07 '18 at 08:00
@DhaanappagoudaPatil. I'm sorry i cant understand what youre saying. But is my solution working? – Joseph May 07 '18 at 08:04
1

This looks unreadable. Why not a simple `while (arr.length > 0) { arr.removeAt(0) }` ? – Mozgor May 21 '19 at 17:00
thank,s that exactly what i am looking for thank,s once again – abubakkar tahir Feb 04 '20 at 10:02

score 2 · Answer 3 · answered May 20 '21 at 09:24

2

As of Angular 8+ you can use clear() to remove all controls in the FormArray:

const arr = new FormArray([
   new FormControl(),
   new FormControl()
]);
console.log(arr.length);  // 2

arr.clear();
console.log(arr.length);  // 0

answered May 20 '21 at 09:24

ᴄᴏᴅᴇ ᴋɪʟʟᴇʀ ᴢʜᴀʀᴀ

393
17

How do I clear the FormArray in Angular Reactive Forms

3 Answers3