Localize xaml markup extension

README.md

This is how I'm doing localization for my first real mobile project. I'm using the Microsoft's localization library. It's a nice library that takes resources from reflected object under the assembly.

Note that I'm using also prism library for xamarin.forms, I found that it is very good tool to have.

Happy coding!

App.es.resx

<?xml version="1.0" encoding="utf-8"?>
<root>
  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
    <xsd:element name="root" msdata:IsDataSet="true">
      <xsd:complexType>
        <xsd:choice maxOccurs="unbounded">
          <xsd:element name="metadata">
            <xsd:complexType>
              <xsd:sequence>
                <xsd:element name="value" type="xsd:string" minOccurs="0" />
              </xsd:sequence>
              <xsd:attribute name="name" use="required" type="xsd:string" />
              <xsd:attribute name="type" type="xsd:string" />
              <xsd:attribute name="mimetype" type="xsd:string" />
              <xsd:attribute ref="xml:space" />
            </xsd:complexType>
          </xsd:element>
          <xsd:element name="assembly">
            <xsd:complexType>
              <xsd:attribute name="alias" type="xsd:string" />
              <xsd:attribute name="name" type="xsd:string" />
            </xsd:complexType>
          </xsd:element>
          <xsd:element name="data">
            <xsd:complexType>
              <xsd:sequence>
                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
              </xsd:sequence>
              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
              <xsd:attribute ref="xml:space" />
            </xsd:complexType>
          </xsd:element>
          <xsd:element name="resheader">
            <xsd:complexType>
              <xsd:sequence>
                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
              </xsd:sequence>
              <xsd:attribute name="name" type="xsd:string" use="required" />
            </xsd:complexType>
          </xsd:element>
        </xsd:choice>
      </xsd:complexType>
    </xsd:element>
  </xsd:schema>
  <resheader name="resmimetype">
    <value>text/microsoft-resx</value>
  </resheader>
  <resheader name="version">
    <value>2.0</value>
  </resheader>
  <resheader name="reader">
    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
  </resheader>
  <resheader name="writer">
    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
  </resheader>
  <data name="Menu" xml:space="preserve">
    <value>Menú</value>
  </data>
</root>

App.xaml.cs

using Prism;
using Prism.Ioc;
using PersonalCompany.ViewModels;
using PersonalCompany.Views;
using Xamarin.Forms;
using Xamarin.Forms.Xaml;
using PersonalCompany.Views.Stocks;
using PersonalCompany.ViewModels.Stocks;
using Microsoft.Extensions.Options;
using Microsoft.Extensions.Localization;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Logging.Abstractions;
using DryIoc;

[assembly: XamlCompilation(XamlCompilationOptions.Compile)]
namespace PersonalCompany
{
    public partial class App
    {
        public App() : this(null) { }

        public App(IPlatformInitializer initializer) : base(initializer) { }

        protected override async void OnInitialized()
        {
            InitializeComponent();

            await NavigationService.NavigateAsync("MasterPage/NavigationPage/MainPage");
        }

        protected override void RegisterTypes(IContainerRegistry containerRegistry)
        {
            // Services:
            containerRegistry.RegisterInstance<IOptions<LocalizationOptions>>(Options.Create(new LocalizationOptions()));
            containerRegistry.RegisterSingleton<ILoggerFactory, NullLoggerFactory>();
            containerRegistry.RegisterSingleton<IStringLocalizerFactory, ResourceManagerStringLocalizerFactory>();

            // We must register a factory for localizers and loggers:
            containerRegistry.Register(typeof(IStringLocalizer<>), typeof(StringLocalizer<>));
            containerRegistry.RegisterSingleton<IStringLocalizer, StringLocalizer<App>>();

            containerRegistry.RegisterForNavigation<MasterPage, MasterPageViewModel>();
            containerRegistry.RegisterForNavigation<NavigationPage>();
            containerRegistry.RegisterForNavigation<MainPage, MainPageViewModel>();
            containerRegistry.RegisterForNavigation<AboutPage, AboutPageViewModel>();
            containerRegistry.RegisterForNavigation<StocksPage, StocksPageViewModel>();
        }
    }
}

LocalizeExtension.cs

using Microsoft.Extensions.Localization;
using System;
using Xamarin.Forms.Xaml;
using Prism.Ioc;
using Xamarin.Forms;

namespace PersonalCompany.Extensions
{
    /// <summary>
    /// Returns a localized string from the input, or the original ones if it was not found.
    /// </summary>
    [ContentProperty(nameof(Message))]
    public class LocalizeExtension : IMarkupExtension<string>
    {
        /// <summary>
        /// Empty constructor required by Xaml
        /// </summary>
        public LocalizeExtension()
        {
        }

        /// <summary>
        /// Returns a localized version of the string.
        /// </summary>
        /// <param name="serviceProvider">A provider that contains XAML specific services.</param>
        /// <returns>The localized message.</returns>
        public string ProvideValue(IServiceProvider serviceProvider)
        {
            var localizer = Prism.PrismApplicationBase.Current?.Container.Resolve<IStringLocalizer>();
            return localizer[Message] ?? Message;
        }

        /// <summary>
        /// Derives this call to <see cref="ProvideValue(IServiceProvider)"/> and returns it's result.
        /// </summary>
        /// <param name="serviceProvider"></param>
        /// <returns></returns>
        object IMarkupExtension.ProvideValue(IServiceProvider serviceProvider)
        {
            return ProvideValue(serviceProvider);
        }

        /// <summary>
        /// The message to be translated.
        /// </summary>
        public string Message { get; set; }
    }
}

MasterPage.xaml

<?xml version="1.0" encoding="utf-8" ?>
<MasterDetailPage xmlns="http://xamarin.com/schemas/2014/forms"
                  xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
                  xmlns:prism="http://prismlibrary.com"
                  xmlns:ext="clr-namespace:PersonalCompany.Extensions"
                  prism:ViewModelLocator.AutowireViewModel="True"
                  x:Class="PersonalCompany.Views.MasterPage">

    <MasterDetailPage.Master>
        <ContentPage Title="{ext:Localize 'Menu'}">
            <StackLayout Padding="20">
                <Button Text="ext:Localize 'About'" Command="{prism:NavigateTo 'NavigationPage/MainPage/AboutPage', SourcePage={x:Reference mdp}}" />
            </StackLayout>
        </ContentPage>
    </MasterDetailPage.Master>
    
</MasterDetailPage>