Friday, July 30, 2021

Set formatters to input fields-With auto country code detect

A set of formatters for text and input fields. Not only it can format a phone number but also automatically detect a country dial code and the name of the country. It also can apply formatting for currencies e.g. you need to convert 100000 into a USD currency value representation. Add MoneyInputFormatter and you can get it e.g. like: $100,000.00…

Formatters Included

  1. Phone Formatter
  2. Credit / Debit Card Formatter
  3. Money Formatter
  4. Masked Formatter

Special utilities

  1. Bitcoin (BTC) wallet validator;
  2. Digit exctractor (allows to extract all digits out of a string)
  3. Phone number validator (the check is based on country phone codes and masks so it's a more serious and reliable validation than a simple regular expression)
  4. "Is digit" checker (Simply checks if an input string value a digit or not)
  5. Currency string formatter (allows to convert a number to a currency string representation e.g. this 10000 to this 10,000.00$)
  6. Unfocuser (a widget that is used to unfocus any text fields without any boilerplate code. Extremely simple to use)

Formatting a phone

PhoneInputFormatter.replacePhoneMask(
    countryCode: 'RU',
    newMask: '+0 (000) 000 00 00',
);
PhoneInputFormatter.addAlternativePhoneMasks(
    countryCode: 'BR',
    alternativeMasks: [
    '+00 (00) 0000-0000',
    '+(00) 00000',
    '+00 (00) 00-0000',
    ],
);
/// There is also a possibility to enter endless phones 
/// by setting allowEndlessPhone to true 
/// this means that you can enter a phone number of any length
/// its part that matches a mask will be formatted 
/// and the rest will be entered unformatted
/// is will allow you to support any phones (even those that are not supported by the formatter yet)
PhoneInputFormatter(
    onCountrySelected: _onCountrySelected,
    allowEndlessPhone: true,
)

Formatting a credit / debit card

Formatting currencies

Using:

import 'package:flutter_multi_formatter/flutter_multi_formatter.dart';

A list of formatters included

/// for phone numbers with a fully automated detection
PhoneInputFormatter

/// for anything that can be masked
MaskedInputFormater

/// for credit / debit cards
CreditCardNumberInputFormatter
CreditCardCvcInputFormatter
CreditCardExpirationDateFormatter

/// for any inputs where you need to restrict or
/// allow some characters
RestrictingInputFormatter

/// for currencies
MoneyInputFormatter

Utility methods and widgets

Validates Bitcoin wallets (also supports bech32)

You can use these example wallets to test the validator

P2PKH addresses start with the number 1 Example: 1BvBMSEYstWetqTFn5Au4m4GFg7xJaNVN2

P2SH addresses start with the number 3 Example: 3J98t1WpEZ73CNmQviecrnyiWrnqRhWNLy

Bech32 addresses also known as “bc1 addresses” start with bc1 Example: bc1qar0srrr7xfkvy5l643lydnw9re59gtzzwf5mdq

/// a simple check if its a BTC wallet or not, regardless of its type
bool isBitcoinWalletValid(String value);

/// a bit more complicated check which can return the type of 
/// BTC wallet and return SegWit (Bech32), Regular, or None if 
/// the string is not a BTC address
BitcoinWalletType getBitcoinWalletType(String value);

/// Detailed check, for those who need to get more details 
/// of the wallet. Returns the address type, the network, and 
/// the wallet type along with its address. 
/// It always returns BitcoinWalletDetails object. To check if it's
/// valid or not use bitcoinWalletDetails.isValid getter
/// IMPORTANT The BitcoinWalletDetails class overrides an 
/// equality operators so two BitcoinWalletDetails objects can be 
/// compared simply like this bwd1 == bwd2
BitcoinWalletDetails getBitcoinWalletDetails(String? value);

Gets all numbers out of a string and joins them into a new string e.g. a string like fGgfjh456bb78 will be converted into this: 45678

import 'package:flutter_multi_formatter/flutter_multi_formatter.dart';

String toNumericString(String text);

returns ‘true’ if the checked character is a digit

import 'package:flutter_multi_formatter/flutter_multi_formatter.dart';

bool isDigit(String character);

toCurrencyString() is used by the MoneyInputFormatter internally but you can also use it directly

import 'package:flutter_multi_formatter/flutter_multi_formatter.dart';

String toCurrencyString(String value, {
    int mantissaLength = 2,
    /// in case you need a period as a thousand separator
    /// simply change ThousandSeparator.Comma to ThousandSeparator.Period
    /// and you will get 1.000.000,00 instead of 1,000,000.00
    ThousandSeparator thousandSeparator = ThousandSeparator.Comma,
    ShorteningPolicy shorteningPolicy = ShorteningPolicy.NoShortening,
    String leadingSymbol = '',
    String trailingSymbol = '',
    bool useSymbolPadding = false
});

print(toCurrencyString('123456', leadingSymbol: MoneySymbols.DOLLAR_SIGN)); // $123,456.00

/// the values can also be shortened to thousands, millions, billions... 
/// in this case a 1000 will be displayed as 1K, and 1250000 will turn to this 1.25M
var result = toCurrencyString(
    '125000', 
    leadingSymbol: MoneySymbols.DOLLAR_SIGN,
    shorteningPolicy: ShorteningPolicy.RoundToThousands
); // $125K

result = toCurrencyString(
    '1250000', 
    leadingSymbol: MoneySymbols.DOLLAR_SIGN,
    shorteningPolicy: ShorteningPolicy.RoundToMillions
); // 1.25M

There’s also an extended version of this function which can be used on double, int and String. But before using it, make sure you use dart sdk version 2.6.0+ open pubspec.yaml and check this section:

environment:
  sdk: ">=2.10.2 <3.0.0"
import 'package:flutter_multi_formatter/flutter_multi_formatter.dart';

var someNumericValue = 123456;
print(someNumericValue.toCurrencyString(leadingSymbol: MoneySymbols.DOLLAR_SIGN)); // $123,456.00

var someNumericStringValue = '123456';
print(someNumericStringValue.toCurrencyString(trailingSymbol: MoneySymbols.EURO_SIGN)); // 123,456.00€
Unfocuser()

Unfocuser allows you to unfocus any text input and hide the onscreen keyboard when you tap outside of a text input. Use it like this:

@override
Widget build(BuildContext context) {
return Unfocuser(
    child: Scaffold(
    body: SingleChildScrollView(
        child: Padding(
        padding: const EdgeInsets.all(30.0),
        child: Form(
            key: _formKey,
            child: Column(
            children: <Widget>[
                TextFormField(
                keyboardType: TextInputType.phone,
                inputFormatters: [
                    PhoneInputFormatter()
                ],
                ),
            ],
            ),
        ),
        ),
    ),
    ),
);
}

More detailed description

PhoneInputFormatter()

Automatically detects the country the phone number belongs to and formats the number according to its mask. You don’t have to care about keeping track of the list of countries or anything else. The whole process is completely automated. You simply add this formatter to the list of formatters like this:

TextFormField(
    keyboardType: TextInputType.phone,
    inputFormatters: [
        PhoneInputFormatter()
    ],
),

You can also get a country data for the selected phone number by simply passing a callback function to your formatter.

TextFormField(
    keyboardType: TextInputType.phone,
    inputFormatters: [
        PhoneInputFormatter(onCountrySelected:  (PhoneCountryData countryData) {
            print(countryData.country);
        });
    ],
),
CreditCardNumberInputFormatter()

CreditCardNumberInputFormatter automatically detects a type of a card based on a predefined list of card system and formats the number accordingly. This detection is pretty rough and may not work with many card system. All supported systems are available as string constants in

class CardSystem {
  static const String VISA = 'Visa';
  static const String MASTERCARD = 'Mastercard';
  static const String JCB = 'JCB';
  static const String DISCOVER = 'Discover';
  static const String MAESTRO = 'Maestro';
  static const String AMERICAN_EXPRESS= 'Amex';
}

Anyway, if the number is not supported it will just be returned as it is and your input will not break because of that

TextFormField(
    keyboardType: TextInputType.number,
    inputFormatters: [
        CreditCardNumberInputFormatter(onCardSystemSelected:  (CardSystemData cardSystemData) {
            print(cardSystemData.system);
        });
    ],
),

/// there's also a method to format a number as a card number
/// the method is located in a credit_card_number_input_formatter.dart file
String formatAsCardNumber(
String cardNumber, {
    bool useSeparators = true,
});

/// and a method to check is a card is valid
bool isCardValidNumber(String cardNumber);
/// but it will return true only if the card system is supported, 
/// so you should not really rely on that

Masked formatter

MaskedInputFormater()

This formatter allows you to easily format a text by a mask This formatter processes current text selection very carefully so that input does not feel unnatural Use it like any other formatters

/// # matches any character and 0 matches digits
/// so, in order to format a string like this GHJ45GHJHN to GHJ-45-GHJHN
/// use a mask like this
TextFormField(
    keyboardType: TextInputType.phone,
    inputFormatters: [
        MaskedInputFormater('###-00-#####')
    ],
),

But in case you want # (hash symbol) to match only some particular values, you can pass a regular expression to [anyCharMatcher] parameter

/// in this scenario, the # symbol will only match uppercase latin letters
TextFormField(
    keyboardType: TextInputType.phone,
    inputFormatters: [
        MaskedInputFormater('###-00-#####', anyCharMatcher: RegExp(r'[A-Z]'))
    ],
),

Money Input formatter

MoneyInputFormatter()
TextFormField(
    keyboardType: TextInputType.number,
    inputFormatters: [
        MoneyInputFormatter(
            leadingSymbol: MoneySymbols.DOLLAR_SIGN
        )
    ],
),
...

TextFormField(
    keyboardType: TextInputType.number,
    inputFormatters: [
        MoneyInputFormatter(
            trailingSymbol: MoneySymbols.EURO_SIGN,
            useSymbolPadding: true,
            mantissaLength: 3 // the length of the fractional side
        )
    ],
),