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What is the purpose of updateOn in Reactive Forms?

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01

Understand the problem

Explain configuration of change events via updateOn ('change' | 'blur' | 'submit').

formsperformance
02

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03

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updateOn determines when form control value and validation status update. Options are 'change' (default, immediate), 'blur' (updates on focus loss), and 'submit' (updates only when the parent form is submitted), which reduces performance overhead.

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04

Read the code

Enabling blur-based updates for a form input
import { FormGroup, FormControl } from '@angular/forms';

const form = new FormGroup({
  username: new FormControl('', {
    updateOn: 'blur',
    validators: []
  }),
  password: new FormControl('', {
    updateOn: 'submit'
  })
});
05

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