/ I18n

A Flutter internationalized strings generator

A Flutter internationalized strings generator


A Flutter internationalized strings generator. The idea is to automate the static Strings generation from a CSV file. This way, anybody could make a CSV file with all the translations and automatically generate corresponding Dart code.

Getting Started

In order to use the flappy_translator package, you will have to provide your translatinos in a CSV file (formatted with comma separator).

Create a CSV and export it in "comma separated" format

Here is our CSV example :

exported file myFile.csv

appTitle,Ma super application,My awesome application,Mi gran application
subtitle,Un sous titre,A subtitle,Un subtitulò
description,Un texte avec une variable : %1$s,A text with a variable : %1$s,Un texto con una variable : %1$s
littleTest,"Voici, pour l'exemple, ""un test"" avec la variable %age$d","Here is, for the example, ""a test"" with variable %age$d","Aqui esta, por ejemplo, ""una prueba"" con la variable %age$d"

Add dependency

    sdk: flutter

Run package

flutter pub get
flutter pub run flappy_translator test.csv path/to/destination

Use the i18n generated file

The package used your CV file in order to generate a file named i18n.dart in path/to/destination you provided.

Once you have this file in your project, all you have to do is :

  1. Add the I18nDelegate to your delegates
class MyApp extends StatelessWidget {
  Widget build(BuildContext context) {
    return MaterialApp(
      localizationsDelegates: [
        const I18nDelegate(),
      supportedLocales: [
        const Locale('en', ''),
        const Locale('fr', ''),
        const Locale('es', ''),
      home: Home(),
  1. Use your generated I18n class ! :)
class Home extends StatelessWidget {
  Widget build(BuildContext context) {
    return Scaffold(
      body: SafeArea(
        child: Center(
          child: Column(
            children: <Widget>[
              Text(I18n.of(context).description(var1: 2)),
              Text(I18n.of(context).littleTest(age: 32)),

Rules and functionnalities

Default language

The first language's column of your CSV file will be considered as the defaultone.
That means :

  • If other languages does not have translation for specific words, it will take the corrresponding one in the default language.

  • The first column must be totally filled ! It will not work otherwise.

Add variables in Strings

We added the possibility to handle variables in the Strings.
This means respecting some rules :

  1. In order to be able to recognize them, you must write them this way :
  • %myVariable$d (d stands for an int type)
  • %myVariable$s (s stands for a String type)
  1. if your variable's name start with a number, the generated name will be varmyVariable
    Otherwise, the generated variable name would be the name you provided.
  • %1$d becomes var1
  • %age$d becomes age
  1. Variables are optional in the generated dart code

Let's take the example of the description String in the CSV we used.

The generated function signature will be :

String description({String var1,})

If the variables are not provided, the String will be given without replacing the variables placeholders.