Good read
rammanusani26-Mar-19 8:09

1 Nov 2016 · all

SaveFile, Italian Language, Salvare il file
SaveFile, French Language, Enregistrer le fichier
... etc
string preferredUserLanguageName = Thread.CurrentThread.CurrentCulture.Name;
Lang user = parse("es-CO");
Lang avail1 = parse("en");
Lang avail2 = parse("es");
Lang defaultL = avail1;

int rank1 = 
          user.Language == avail.Language ? 32: -32  
       + 
          user.Script == avail.Script ? 16 : -16
       +
           //... and so on ..
     //decide your policy for matching language in order to provide better service to the user
;
int rank2 = //..

if(rank1 > rank2 && rank1>0)
       return avail1;
else if(rank2 > rank1 && rank2>0)
       return avail2;
return defaultL;
Type: grandfathered
Tag: i-klingon
Description: Klingon
Added: 1999-05-26
Deprecated: 2004-02-24
Preferred-Value: tlh
primarylanguage
 ["-" extlang]
 ["-" script]
 ["-" region]
*("-" variant)
*("-" extension)
 ["-" privateuse]
bcp47.LangSet s = new bcp47.LangSet();
s.Add("en-US"); //this will be the default language, the first added
s.Add("de");//German
s.Add("fr");//French
s.Add("ja");//Japanese
s.Add("es");//Spanish
string userPreferredLanguage = "es-CO";
Lang bestMatchOrDefault = s.Lookup(test); //will return "es"
//good now i can show the user the product description searching my database for 
//the description which have bestMatchOrDefault.Canonical tag
string ProductDescriptionText = myTranlationDatabase.Translate("ProductDescription", bestMatchOrDefault.Canonical);
public static Registry Load(StreamReader sr)
{
    Registry u = new Registry();
    var d = NextRecord(sr);

    if (d.Count != 1 || !d.ContainsKey("File-Date") || DateTime.TryParseExact(d["File-Date"], "yyyy-mm-dd", System.Globalization.CultureInfo.InvariantCulture, System.Globalization.DateTimeStyles.AllowTrailingWhite, out u.registryUpdated) == false)
        throw new FormatException();

    while (!sr.EndOfStream)
    {
        d = NextRecord(sr);
        CheckRecord(d);

        if (d["Type"] == "language")
        {
            u.languageIndex.Add(d["Subtag"], ParseRecord(d));
        }
        else if (d["Type"] == "extlang")
        {
            u.extlangIndex.Add(d["Subtag"], ParseRecord(d));
        }
        else if (d["Type"] == "script")
        {
            u.scriptIndex.Add(d["Subtag"], ParseRecord(d));
        }
        else if (d["Type"] == "region")
        {
            u.regionIndex.Add(d["Subtag"], ParseRecord(d));
        }
        else if (d["Type"] == "variant")
        {
            u.variantIndex.Add(d["Subtag"], ParseRecord(d));
        }
        else if (d["Type"] == "grandfathered")
        {
            u.grandfatheredIndex.Add(d["Tag"], ParseRecord(d));
        }
        else if (d["Type"] == "redundant")
        {
            u.redundantIndex.Add(d["Tag"], ParseRecord(d));
        }
    }
    return u;
}
 public class Record
    {
        public readonly string Type;
        public readonly string Subtag;
        public readonly string Tag;
        public readonly string PreferredValue;
        public readonly string Description;
        public readonly DateTime Created;
        public readonly string SuppressScript;
        public readonly string MacroLanguage;
        readonly HashSet<string> Prefix;
//...
   }
 public class Lang : IEquatable<Lang>
 {
     //all fields are readonly thus i'm thread safe
     public readonly Record Language;
     public readonly Record ExtLang;
     public readonly Record Script;
     public readonly Record Region;
     public readonly ReadOnlyCollection<Record> Variants;
     public readonly ReadOnlyDictionary<char, ReadOnlyCollection<string>> Extensions;
     public readonly string Private;
     public readonly string Canonical;
}

Lang l = Lang.Parse("es-CO");
Console.WriteLine("Lang: {0}", l.Language?.Description.Replace('\n',','));
Console.WriteLine("ExtLang: {0}", l.ExtLang?.Description);
Console.WriteLine("Script: {0}", l.Script?.Description);
Console.WriteLine("Region: {0}", l.Region?.Description);
//Lang: Spanish,Castilian
//ExtLang:
//Script: Latin
//Region: Colombia
a language tag processor need not have a list of valid tags or subtags in order to perform common searching and matching operations.

IETF language tags and IANA language subtag registry

Introduction

Some philosophy

IETF language tags application

Why a standard

How localization is implemented in .NET

Why did you study and implement BCP47?

Ok but why an article

Background

Lookup a language

Why is using the registry better?

Net Framework Localization Reference

BCP47 language tag syntax

Private Tags

Grandfathered Tags

Normal Language Tag

Primary Language Sub Tag

Extlang Sub Tag

Script Sub Tag

Region Sub Tag

Variant Sub Tag

Extension Sub Tag and Private Sub Tag

The IANA Language Subtag registry

Using the code

Points of Interest

About the provided implementation

What could be improved

Registry Parser

Registry record

The Language Tag Parser

The lookup algorithm

History

License

Comments and Discussions