Angular 5 solely validation on blur?

Question

I wonder if it is possible to have the validation in reactive forms on blur. At the moment you can set updateOn: "blur" but then the values of the input fields won't update on input. In my case i need the values to be updated on every keystroke because I do calculations with it and show the result to the user. The validation should only happen on blur.

thx.

EDIT:

I use FormBuilder, some build in validators and some custom validators. Example code:

let formToMake = {
  purpose: [null, Validators.required],
  registrationDate: this.fb.group({
    day: [null, Validators.required],
    month: [null, Validators.required],
    year: [null, Validators.required]
  }),
  isTruth: [null, Validators.compose([checkIfTrue, Validators.required])]
};

If i would use the blur event i need to do all my validation manually, which i think is not a good way.

Answer 1

What I eventually have done:

Using reactive forms:

TS

this is the form to make. I needed the productCost and loanAmount to be validated on blur but the values itself needed to update onchange. If you set updateOn: "blur" the validation happens after the blur event but als the values will update after the blur event.

let formToMake = {
      productCost: new FormControl(null, {validators: Validators.required, updateOn: "blur"}),
      loanAmount: new FormControl(null, {validators: Validators.compose([Validators.required, Validators.min(2500)]), updateOn: "blur"}),
      loanLength: new FormControl(49, {validators: Validators.required, updateOn: "change"})
    };

handleInput method:

To solve this I just made an event handler which will be called on the input event.

TS

handleInput(e: any) {
    this.loanAmount = e;
  }

HTML

<input class="form__input" type="number" value="{{loanForm.get('loanAmount').value}}" id="loanAmount" formControlName="loanAmount" (input)="handleInput($event.target.value)">