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Strip the country code from autofill and paste
This detail uses
+994, the Azerbaijani country code. For your country, adapt it yourself or ask your AI agent.
Your phone field shows a fixed +994 prefix on the left, so users type only the national number. Then they paste their number with +994 in front, or autofill inserts it as a full international string, and the country code ends up in the field twice. Catch it with a formatter, so only the national number lands:
You can't control what gets inserted. But every change to the text goes through inputFormatters: keystrokes, paste, and autofill all arrive as an ordinary edit. Strip the dial code there:
import 'package:flutter/services.dart';
class StripDialCodeFormatter extends TextInputFormatter {
static const String _dialCode = '994';
static final RegExp _nonDigits = RegExp(r'[^0-9]');
@override
TextEditingValue formatEditUpdate(
TextEditingValue oldValue,
TextEditingValue newValue,
) {
// A keystroke grows the text by one character.
// Paste and autofill grow it by many.
final bool bulk = newValue.text.length - oldValue.text.length > 1;
if (!bulk) return newValue;
final String digits = newValue.text.replaceAll(_nonDigits, '');
String national = digits;
if (digits.startsWith('00$_dialCode')) {
national = digits.substring(2 + _dialCode.length);
} else if (newValue.text.trimLeft().startsWith('+') &&
digits.startsWith(_dialCode)) {
national = digits.substring(_dialCode.length);
}
return TextEditingValue(
text: national,
selection: TextSelection.collapsed(offset: national.length),
);
}
}How it decides:
Typed input passes through. The formatter only acts when the text grows by more than one character, so typing is never touched.
+994... and 00994... are clearly international: strip the dial code.
Wire it up:
TextField(
keyboardType: TextInputType.phone,
autofillHints: const [
AutofillHints.telephoneNumber,
],
inputFormatters: [
StripDialCodeFormatter(),
],
decoration: const InputDecoration(
prefixText: '+994 ',
hintText: '501234567',
),
)autofillHints is what makes the OS offer the number in the first place. Keep it: the formatter makes autofill safe, so users keep the one-tap sign-in.