How to localize percentage values in Dart/Flutter correctly?

flutter dart localization

591

First add intl package into your pubspec.yaml

Use the Localisation and NumberFormat class.

Locale myLocale = Localizations.localeOf(context); /* gets the locale based on system language*/

String languageCode = myLocale.languageCode;

print(NumberFormat.percentPattern(languageCode).format (60.23));

You can refer here for the the supported locales : https://www.woolha.com/tutorials/dart-formatting-currency-with-numberformat#supported-locales

591

Author by

Dark Purple Knight

Updated on December 30, 2022

Comments

Dark Purple Knight over 1 year
I am still looking for a better way to localize a percentage value in Dart/Flutter. So far, I'm just converting a percentage value to a suitable string with the following code: '${(_percentage * 100).toStringAsFixed(3)}%'

For a percentage value of e.g. 65.7893 you get the following string: 65.789%. That's fine for English, but not for other languages.

For example, for German, the string should be as follows: 65,789 %

Solution

Thanks to the useful tips, I have now created the following wrapper function.
```
import 'package:flutter/material.dart';
import 'package:intl/intl.dart';

 _generatePercentString(percentValue) {
    var systemLocale = Localizations.localeOf(context);
    var numberFormatter = NumberFormat.decimalPercentPattern(
      locale: systemLocale.languageCode,
      decimalDigits: 3,
    );
    var percentString = numberFormatter.format(percentValue);
    return percentString;
  }
```
- jamesdlin almost 3 years
  
  Does NumberFormat (specifically, NumberFormat.percentPattern) from package:intl not do what you want?
- Dark Purple Knight almost 3 years
  
  NumberFormat.percentPattern requires a locale string, although I only want to use the system language.
- jamesdlin almost 3 years
  
  The locale argument is optional. I presume it uses the current locale if not specified.
- Dark Purple Knight almost 3 years
  
  In my tests with different locals, the generated strings were always appropriate for English.
- jamesdlin almost 3 years
  
  If that's the case, then you could pretty trivially create a wrapper function or extension method that automatically calls it with the current locale.
- Dark Purple Knight almost 3 years
  
  That would be an easy solution to implement. I guess there is no simpler solution with even less code.
Dark Purple Knight almost 3 years

I would like to avoid specifying a locale string for each percentage value, because the formatting should only match the system language.
Niteesh almost 3 years

I've updated the answer to solve your query.
Dark Purple Knight almost 3 years

I will create a wrapper function for it.
Dark Purple Knight almost 3 years

languageCode is a getter.
Niteesh almost 3 years

Sorry, It was a mistake, my bad, it's a property