Internationalization - See code comments for usage

I18n.cs

/*
 * Internationalization 
 * 
 * Author: Daniel Erdmann
 * 
 * 1. Add this File to you Project
 * 
 * 2. Add the language files to the folder Assets/Resources/I18n. (Filesnames: en.txt, es.txt, pt.txt, de.txt, and so on)
 *    Format: en.txt:           es.txt:
 *           =============== =================
 *           |hello=Hello  | |hello=Hola     |
 *           |world=World  | |world=Mundo    |
 *           |...          | |...            |
 *           =============== =================
 *           
 * 3. Use it! 
 *    Debug.Log(I18n.Fields["hello"] + " " + I18n.Fields["world"]); //"Hello World" or "Hola Mundo"
 * 
 * Use \n for new lines. Fallback language is "en"
 */

using System;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

class I18n
{
    /// <summary>
    /// Text Fields
    /// Useage: Fields[key]
    /// Example: I18n.Fields["world"]
    /// </summary>
    public static Dictionary<String, String> Fields { get; private set; }

    /// <summary>
    /// Init on first use
    /// </summary>
    static I18n()
    {
        LoadLanguage();
    }

    /// <summary>
    /// Load language files from ressources
    /// </summary>
    private static void LoadLanguage()
    {
        if (Fields == null)
            Fields = new Dictionary<string, string>();

        Fields.Clear();
        string lang = Get2LetterISOCodeFromSystemLanguage().ToLower();
        //lang = "de";
        var textAsset = Resources.Load(@"I18n/" + lang); //no .txt needed
        string allTexts = "";
        if (textAsset == null)
            textAsset = Resources.Load(@"I18n/en") as TextAsset; //no .txt needed
        if (textAsset == null)
            Debug.LogError("File not found for I18n: Assets/Resources/I18n/" + lang + ".txt");
        allTexts = (textAsset as TextAsset).text;
        string[] lines = allTexts.Split(new string[] { "\r\n", "\n" },
            StringSplitOptions.None);
        string key, value;
        for (int i = 0; i < lines.Length; i++)
        {
            if (lines[i].IndexOf("=") >= 0 && !lines[i].StartsWith("#"))
            {
                key = lines[i].Substring(0, lines[i].IndexOf("="));
                value = lines[i].Substring(lines[i].IndexOf("=") + 1,
                        lines[i].Length - lines[i].IndexOf("=") - 1).Replace("\\n", Environment.NewLine);
                Fields.Add(key, value);
            }
        }
    }

    /// <summary>
    /// get the current language
    /// </summary>
    /// <returns></returns>
    public static string GetLanguage()
    {
        return Get2LetterISOCodeFromSystemLanguage().ToLower();
    }

    /// <summary>
    /// Helps to convert Unity's Application.systemLanguage to a 
    /// 2 letter ISO country code. There is unfortunately not more
    /// countries available as Unity's enum does not enclose all
    /// countries.
    /// </summary>
    /// <returns>The 2-letter ISO code from system language.</returns>
    public static string Get2LetterISOCodeFromSystemLanguage()
    {
        SystemLanguage lang = Application.systemLanguage;
        string res = "EN";
        switch (lang)
        {
            case SystemLanguage.Afrikaans: res = "AF"; break;
            case SystemLanguage.Arabic: res = "AR"; break;
            case SystemLanguage.Basque: res = "EU"; break;
            case SystemLanguage.Belarusian: res = "BY"; break;
            case SystemLanguage.Bulgarian: res = "BG"; break;
            case SystemLanguage.Catalan: res = "CA"; break;
            case SystemLanguage.Chinese: res = "ZH"; break;
            case SystemLanguage.ChineseSimplified: res = "ZH"; break;
            case SystemLanguage.ChineseTraditional: res = "ZH"; break;
            case SystemLanguage.Czech: res = "CS"; break;
            case SystemLanguage.Danish: res = "DA"; break;
            case SystemLanguage.Dutch: res = "NL"; break;
            case SystemLanguage.English: res = "EN"; break;
            case SystemLanguage.Estonian: res = "ET"; break;
            case SystemLanguage.Faroese: res = "FO"; break;
            case SystemLanguage.Finnish: res = "FI"; break;
            case SystemLanguage.French: res = "FR"; break;
            case SystemLanguage.German: res = "DE"; break;
            case SystemLanguage.Greek: res = "EL"; break;
            case SystemLanguage.Hebrew: res = "IW"; break;
            case SystemLanguage.Hungarian: res = "HU"; break;
            case SystemLanguage.Icelandic: res = "IS"; break;
            case SystemLanguage.Indonesian: res = "IN"; break;
            case SystemLanguage.Italian: res = "IT"; break;
            case SystemLanguage.Japanese: res = "JA"; break;
            case SystemLanguage.Korean: res = "KO"; break;
            case SystemLanguage.Latvian: res = "LV"; break;
            case SystemLanguage.Lithuanian: res = "LT"; break;
            case SystemLanguage.Norwegian: res = "NO"; break;
            case SystemLanguage.Polish: res = "PL"; break;
            case SystemLanguage.Portuguese: res = "PT"; break;
            case SystemLanguage.Romanian: res = "RO"; break;
            case SystemLanguage.Russian: res = "RU"; break;
            case SystemLanguage.SerboCroatian: res = "SH"; break;
            case SystemLanguage.Slovak: res = "SK"; break;
            case SystemLanguage.Slovenian: res = "SL"; break;
            case SystemLanguage.Spanish: res = "ES"; break;
            case SystemLanguage.Swedish: res = "SV"; break;
            case SystemLanguage.Thai: res = "TH"; break;
            case SystemLanguage.Turkish: res = "TR"; break;
            case SystemLanguage.Ukrainian: res = "UK"; break;
            case SystemLanguage.Unknown: res = "EN"; break;
            case SystemLanguage.Vietnamese: res = "VI"; break;
        }
        //		Debug.Log ("Lang: " + res);
        return res;
    }

}

I18nTextTranslator.cs

using UnityEngine;
using UnityEngine.UI;

public class I18nTextTranslator : MonoBehaviour
{
    public string TextId;

    // Use this for initialization
    void Start()
    {
        var text = GetComponent<Text>();
        if (text != null)
            if(TextId == "ISOCode")
                text.text = I18n.GetLanguage();
            else
                text.text = I18n.Fields[TextId];
    }

    // Update is called once per frame
    void Update()
    {

    }
}

can anyone tell me how to attach the language selection to a ui dropdown?

Could you be a little more specific, so that anyone can look down to the issue more accurately?

Hello, please tell me how to make a language selection via the dropdown?

polish characters not working pls tell me how to have polish characters!

polish characters not working pls tell me how to have polish characters!

it depends on the fount you are using

polish characters not working pls tell me how to have polish characters!

it depends on the fount you are using

default font in unity text

polish characters not working pls tell me how to have polish characters!

it depends on the fount you are using

default font in unity text

Arial works fine for me.

polish characters not working pls tell me how to have polish characters!

it depends on the fount you are using

default font in unity text

Arial works fine for me.

for me it's black-background triangle with ? on center

polish characters not working pls tell me how to have polish characters!

it depends on the fount you are using

default font in unity text

Arial works fine for me.

for me it's black-background triangle with ? on center

� this

Thanks!

polish characters not working pls tell me how to have polish characters!

it depends on the fount you are using

default font in unity text

Arial works fine for me.

for me it's black-background triangle with ? on center

� this

did you tried putting it in English, and then put the translation of it in Unity?

polish characters not working pls tell me how to have polish characters!

it depends on the fount you are using

default font in unity text

Arial works fine for me.

for me it's black-background triangle with ? on center

� this

did you tried putting it in English, and then put the translation of it in Unity?

I'm polish, so I did polish game and now I'm translating it to English, but I needed to write into pl.txt all of my polish texts because if polish client has been detected by I18n and pl.txt is empty it gives just blank text fields. But when I wrote polish character in pl.txt it shows this symbol. Ahh yes, when polish character it gives an error about... Dictionary error?

polish characters not working pls tell me how to have polish characters!

it depends on the fount you are using

default font in unity text

Arial works fine for me.

for me it's black-background triangle with ? on center

� this

did you tried putting it in English, and then put the translation of it in Unity?

I'm polish, so I did polish game and now I'm translating it to English, but I needed to write into pl.txt all of my polish texts because if polish client has been detected by I18n and pl.txt is empty it gives just blank text fields. But when I wrote polish character in pl.txt it shows this symbol. Ahh yes, when polish character it gives an error about... Dictionary error?

Check source file coding (pl.txt) and make sure it is UTF-8 without BOM.

If someone is using TextMeshPro, in I18nTextTranslator.cs you need to add:

using TMPro;

then change:
var text = GetComponent();
to
var text = GetComponent();

and it should be working fine.

I've added small helper method to use with string.Format()
forked gist

so it can be used with some arguments
hi0=Hi {0}!

    /// <summary>
    /// Helper for string format and translation keys.  
    /// </summary>
    /// <param name="key">as in translation file</param>
    /// <param name="args">optional parameters to be put in output if they are provided in tranlstion file for ex.: hi0=Hi {0}!</param>
    /// <returns>translated string based </returns>
    public static string T(string key, params object [] args)
    {
        string kText = Fields.ContainsKey(key) ? Fields[key] : "( "+ key +")";
        return String.Format(kText, args);
    }

cannot use GetSysteLanguage from monobehaviour constructor