SharedLocalization

Implementation of localization in shared xamarin forms.

WHY?

When you want to find info about how to "do" localization in Xamarin, there are enough results from .Net Standard projects, but not from __"SharedProject"__.
And in __"SharedProject"__ there are some problems with this topic.
## Problem:
*   You cannot create .resx files in __"SharedProject"__, but you can manualy copy it to the project and then include to the project. Furthemore this .resx files won`t be copied to the Android  or IOS projects. You will get erros when trying to translate.

Manual for simple solution

First of all we need to add a new Class Library to our solution(for example: SharedLocalization.Common)

Then create a folder named "Resources" where will be located our .resx files for necessary languages.

Naming

This is really important, you must be carefull about the file names. Every filename MUST correspond to the CultureInfo Name property in lower case (en,pl,ru...).

Example: Your default(en) .resx file has name "AppResource". For the next languages you should add a prefix to the name of file: "AppResource.de.resx" - for German language.

When resx files created and filled with values you should create class which will process data and return translated strings for each language.

Working with ResourceManager

using System.Globalization; using System.Reflection; using System.Resources;

namespace SharedLocalization.Common
{
    public class DictionaryManager
    {
        public string Translate(string key)
        {
            ResourceManager rm = new ResourceManager("SharedLocalization.Common.Resources.Resource", typeof(DictionaryManager).GetTypeInfo().Assembly);

            var currentCulture = CultureInfo.DefaultThreadCurrentCulture;
            return rm.GetString(key, currentCulture);
        }
    }
}

First parametr of new ResourceManager() is path(localization) to your default .resx file. As settings of culture is setted globally for the solution, when we will change CultureInfo in "SharedProject" in our "Common" project we will see chages too.

Android, IOS Projects

Then add reference from Android and IOS to our "Common" project.

Shared Project

After that in "SharedProject" we should create class, which will help translate our keys.

-Shared project
 |
 |-Helpers
     |- Localization
        |- TranslateExtension.cs
 |- Views
 |- etc.

Code of TranslateExtension.cs

    [ContentProperty("Text")]
    public class TranslateExtension : IMarkupExtension
    {
        public string Text { get; set; }

        public object ProvideValue(IServiceProvider serviceProvider)
        {
            if (Text == null)
                return "";

            return new DictionaryManager().Translate(Text);
        }
    }

MainPage.xaml

Then in our MainPage.xaml we can "call" this class, lets name it "i18n":

    <ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:i18n="clr-namespace:SharedLocalization.Helpers.Localization;"
             x:Class="SharedLocalization.MainPage">

Synatax for translate is quite simple:

    {i18n:Translate HelloWorld}

1. our attribute;
1. Property for transfer data;
1. key in our .resx file;

MainPage.xaml.cs

And last add event listner to change language:

 private void LanguagePicker_OnSelectedIndexChanged(object sender, EventArgs e)
    {
        string selectedLanguage = languagePicker.SelectedItem.ToString();
        CultureInfo.DefaultThreadCurrentCulture = new CultureInfo(selectedLanguage);

        InitializeComponent();
    }

Mynken / SharedLocalization