= .Net core =
.NET Core to develop console or Web applications. .NET Core is a set of runtime, library and compiler components that allow you to create apps that run on Windows, macOS and Linux.

 * https://www.microsoft.com/net/learn/get-started/windows
 * https://en.wikipedia.org/wiki/ASP.NET_Core
 * https://hub.docker.com/r/microsoft/dotnet/
 * https://docs.microsoft.com/pt-pt/dotnet/core/docker/building-net-docker-images
 * https://msdn.microsoft.com/en-us/library/ff361664(v=vs.110).aspx

In browser tutorial
 * https://www.microsoft.com/net/learn/in-browser-tutorial/1

== Sample hello world ==
{{{
.
├── appSolution.sln
├── Dockerfile
├── myApp
│   ├── myApp.csproj
│   └── Program.cs
├── myLib
│   ├── Class1.cs
│   └── myLib.csproj
├── myLibTests
│   ├── myLibTests.csproj
│   └── UniTest1.cs
}}}

=== Dockerfile ===
{{{
FROM microsoft/dotnet:2.0-sdk
WORKDIR /app
RUN apt-get update
RUN apt-get install net-tools procps vim nano -y
RUN mkdir -p /app/myApp
RUN mkdir -p /app/myLib
RUN mkdir -p /app/myLibTests
ADD myApp/* /app/myApp/
ADD myLib/* /app/myLib/
ADD myLibTests/* /app/myLibTests/
ADD appSolution.sln /app/
RUN cd /app && dotnet clean && dotnet build
RUN cd /app/myLibTests && dotnet clean && dotnet test
CMD cd /app/myApp/ && dotnet bin/Debug/netcoreapp2.0/myApp.dll && tail -f /var/log/lastlog
#CMD  tail -f /var/log/lastlog
}}}

=== appSolution.sln ===
{{{

Microsoft Visual Studio Solution File, Format Version 12.00
# Visual Studio 15
VisualStudioVersion = 15.0.26124.0
MinimumVisualStudioVersion = 15.0.26124.0
Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "myApp", "myApp\myApp.csproj", "{5E009AC4-9BF5-4E1B-9C22-377AC9ECC4EB}"
EndProject
Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "myLib", "myLib\myLib.csproj", "{00D6703F-2D64-4D9A-95AA-430DC38E4EC3}"
EndProject
Global
        GlobalSection(SolutionConfigurationPlatforms) = preSolution
                Debug|Any CPU = Debug|Any CPU
                Debug|x64 = Debug|x64
                Debug|x86 = Debug|x86
                Release|Any CPU = Release|Any CPU
                Release|x64 = Release|x64
                Release|x86 = Release|x86
        EndGlobalSection
        GlobalSection(SolutionProperties) = preSolution
                HideSolutionNode = FALSE
        EndGlobalSection
        GlobalSection(ProjectConfigurationPlatforms) = postSolution
                {5E009AC4-9BF5-4E1B-9C22-377AC9ECC4EB}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
                {5E009AC4-9BF5-4E1B-9C22-377AC9ECC4EB}.Debug|Any CPU.Build.0 = Debug|Any CPU
                {5E009AC4-9BF5-4E1B-9C22-377AC9ECC4EB}.Debug|x64.ActiveCfg = Debug|x64
                {5E009AC4-9BF5-4E1B-9C22-377AC9ECC4EB}.Debug|x64.Build.0 = Debug|x64
                {5E009AC4-9BF5-4E1B-9C22-377AC9ECC4EB}.Debug|x86.ActiveCfg = Debug|x86
                {5E009AC4-9BF5-4E1B-9C22-377AC9ECC4EB}.Debug|x86.Build.0 = Debug|x86
                {5E009AC4-9BF5-4E1B-9C22-377AC9ECC4EB}.Release|Any CPU.ActiveCfg = Release|Any CPU
                {5E009AC4-9BF5-4E1B-9C22-377AC9ECC4EB}.Release|Any CPU.Build.0 = Release|Any CPU
                {5E009AC4-9BF5-4E1B-9C22-377AC9ECC4EB}.Release|x64.ActiveCfg = Release|x64
                {5E009AC4-9BF5-4E1B-9C22-377AC9ECC4EB}.Release|x64.Build.0 = Release|x64
                {5E009AC4-9BF5-4E1B-9C22-377AC9ECC4EB}.Release|x86.ActiveCfg = Release|x86
                {5E009AC4-9BF5-4E1B-9C22-377AC9ECC4EB}.Release|x86.Build.0 = Release|x86
                {00D6703F-2D64-4D9A-95AA-430DC38E4EC3}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
                {00D6703F-2D64-4D9A-95AA-430DC38E4EC3}.Debug|Any CPU.Build.0 = Debug|Any CPU
                {00D6703F-2D64-4D9A-95AA-430DC38E4EC3}.Debug|x64.ActiveCfg = Debug|x64
                {00D6703F-2D64-4D9A-95AA-430DC38E4EC3}.Debug|x64.Build.0 = Debug|x64
                {00D6703F-2D64-4D9A-95AA-430DC38E4EC3}.Debug|x86.ActiveCfg = Debug|x86
                {00D6703F-2D64-4D9A-95AA-430DC38E4EC3}.Debug|x86.Build.0 = Debug|x86
                {00D6703F-2D64-4D9A-95AA-430DC38E4EC3}.Release|Any CPU.ActiveCfg = Release|Any CPU
                {00D6703F-2D64-4D9A-95AA-430DC38E4EC3}.Release|Any CPU.Build.0 = Release|Any CPU
                {00D6703F-2D64-4D9A-95AA-430DC38E4EC3}.Release|x64.ActiveCfg = Release|x64
                {00D6703F-2D64-4D9A-95AA-430DC38E4EC3}.Release|x64.Build.0 = Release|x64
                {00D6703F-2D64-4D9A-95AA-430DC38E4EC3}.Release|x86.ActiveCfg = Release|x86
                {00D6703F-2D64-4D9A-95AA-430DC38E4EC3}.Release|x86.Build.0 = Release|x86
        EndGlobalSection
EndGlobal
}}}

=== myApp/Program.cs ===

{{{#!highlight csharp
using System;
using myLib;

namespace myApp
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine( Class1.getHelloWorld() );
        }
    }
}
}}}

=== myApp/myApp.csproj ===
{{{#!highlight xml
<Project Sdk="Microsoft.NET.Sdk">

  <ItemGroup>
    <ProjectReference Include="..\myLib\myLib.csproj" />
  </ItemGroup>

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>netcoreapp2.0</TargetFramework>
  </PropertyGroup>

</Project>
}}}

=== myLib/Class1.cs ===
{{{#!highlight csharp
using System;

namespace myLib
{
    public class Class1
    {
        public static String getHelloWorld()
        {
            return "Hello world from library.";
        }
    }
}
}}}

=== myLib/myLib.csproj ===
{{{#!highlight xml
<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>netstandard2.0</TargetFramework>
  </PropertyGroup>

</Project>
}}}

=== myLibTests/UniTest1.cs ===
{{{#!highlight csharp
using System;
using Xunit;
using myLib;

namespace myLibTests
{
    public class UnitTest1
    {
        [Fact]
        public void Test1()
        {
            Assert.Equal("Hello world from library." , Class1.getHelloWorld() );
        }
    }
}
}}}

=== myLibTests/myLibTests.csproj ===
{{{#!highlight xml
<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>netcoreapp2.0</TargetFramework>

    <IsPackable>false</IsPackable>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.6.0" />
    <PackageReference Include="xunit" Version="2.3.1" />
    <PackageReference Include="xunit.runner.visualstudio" Version="2.3.1" />
    <DotNetCliToolReference Include="dotnet-xunit" Version="2.3.1" />
  </ItemGroup>

  <ItemGroup>
    <ProjectReference Include="..\myLib\myLib.csproj" />
  </ItemGroup>

</Project>
}}}

=== Docker commands ===
{{{#!highlight bash
#build image
docker build -t dotnetcorehello .
# execute bash in running container
docker exec -it $1 bash
# delete all containers
docker ps -a | awk '//{print $1}' | grep  -v "CONTAINER" | xargs -i sh -c 'docker stop {};docker rm {}'
# execute container using inage dotnetcorehello
docker run -d  dotnetcorehello
# list all containers
docker ps -a
}}}

=== dotnet core commands ===
{{{#!highlight bash
# build solution
cd /app 
dotnet clean 
dotnet build
# run tests for library myLibTests
cd /app/myLibTests 
dotnet clean 
dotnet test
# execute app
cd /app/myApp/ 
dotnet bin/Debug/netcoreapp2.0/myApp.dll
}}}

== test Task ==
{{{#!highlight csharp
// buiild and run with mono
// mcs testTask.cs 
// mono testTask.exe 

using System;
using System.Threading.Tasks;
using System.Threading;
// string interpolation with $ might not be supported in mono

namespace testTask
{
    class Program
    {
        static void Main()
        {
            var x=1;
            // String interpolation $"{varxyz}"
            //Console.WriteLine($"ThreadId {Thread.CurrentThread.ManagedThreadId}");
            Console.WriteLine("ThreadId {0}",Thread.CurrentThread.ManagedThreadId);
            Task t = Task.Run( () => {
                x++;
                Console.WriteLine("Stuff");
                //Console.WriteLine($"ThreadId {Thread.CurrentThread.ManagedThreadId}");
                Console.WriteLine("ThreadId {0}",Thread.CurrentThread.ManagedThreadId);
            } );
            t.ContinueWith((Task task)=>{
                x++;
                Console.WriteLine("This the end !");
                //Console.WriteLine($"ThreadId {Thread.CurrentThread.ManagedThreadId}");
                Console.WriteLine("ThreadId {0}",Thread.CurrentThread.ManagedThreadId);
                task.ContinueWith((Task t2)=>{
                    x++;
                    Console.WriteLine("t2 {0}",x);
                    Console.WriteLine("ThreadId {0}",Thread.CurrentThread.ManagedThreadId);
                });
            });
            //t.Wait();  
            var tx = Task<long>.Run( ()=>{ return 11L; } );

            tx.ContinueWith((Task<long> txy)=>{
                //Console.WriteLine($"Res: {txy.Result}");
                Console.WriteLine("Res: {0}",txy.Result);
            });         
        }
    }
}
}}}


== test foreach ==
{{{#!highlight csharp
//build and run using mono
//mcs testForeach.cs 
//mono testForeach.exe
using System;
using System.Collections.Generic;

namespace loopNrs
{
    class Program
    {
        static void Main()
        {
            var numbers = new List<long> { 1,2,3,4 };
            foreach (var nr in numbers)
            {
                //string interpolation is not supported in mono !?
                // Console.WriteLine($"Hello {nr}!");
                Console.WriteLine("Hello {0}!",nr);
            }
        }
    }
}
}}}

== Sample DI ==
Commands:
 * dotnet build
 *  dotnet .\bin\Debug\netcoreapp2.0\testDI.dll

=== testDI.csproj ===
{{{#!highlight xml
<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>netcoreapp2.0</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="2.0.0" />
  </ItemGroup>

</Project>
}}}

=== Program.cs ===
{{{#!highlight csharp
using System;
using Microsoft.Extensions.DependencyInjection;

namespace testDI
{
    interface IDummy : IDisposable
    {
        string GetPong();
    }

    interface ISnafu : IDisposable
    {
        string GetSnafu();
    }
    
    interface ITransx : IDisposable
    {
        string GetTransx();
    }
    
    class Transx : ITransx
    {
        private string guid;
        
        public Transx()
        {
            guid = Guid.NewGuid().ToString();
            Console.WriteLine($"Constructed transx {guid} !");
        }
        
        public string GetTransx()
        {
            return $"Transx {guid} !";
        }
        
        public void Dispose()
        {
            Console.WriteLine($"Disposing transx {guid} !");
        }        
    }
    
    class Dummy : IDummy
    {
        private string guid;
        
        public Dummy()
        {
            guid = Guid.NewGuid().ToString();
            Console.WriteLine($"Constructed dummy {guid} !");
        }
        
        public string GetPong()
        {
            return $"Pong {guid} !";
        }
        
        public void Dispose()
        {
            Console.WriteLine($"Disposing dummy {guid} !");
        }
    }
    
    class Snafu:ISnafu
    {
        private IDummy dummy;
        private string guid;
        
        public Snafu(IDummy dummy)
        {
            this.dummy = dummy;
            guid = Guid.NewGuid().ToString();
            Console.WriteLine($"Constructed snafu {guid} !");
        }
        
        public string GetSnafu()
        {
            return $"Snafu {guid} related with {dummy.GetPong() }!";
        }
        
        public void Dispose()
        {
            Console.WriteLine($"Disposing snafu {guid} !");
        }        
    }
    
    class Program
    {
        private static IServiceProvider ioc; //Default implementation ServiceProvider
        
        private static void PrepareContainer()
        {
            var serviceCollection = new ServiceCollection();
            serviceCollection.AddSingleton<IDummy, Dummy>();
            serviceCollection.AddSingleton<ISnafu, Snafu>();
            serviceCollection.AddTransient<ITransx, Transx>();
            ioc = serviceCollection.BuildServiceProvider();            
        }
        
        static void Main(string[] args)
        {
            Console.WriteLine("Hello World DI!");
            TestOne();
            TestTwo();
        }
        
        private static void TestOne()
        {
            Console.WriteLine("\nTestOne");
            PrepareContainer();
            var d1 = ioc.GetService<IDummy>();
            Console.WriteLine( $"{d1.GetPong()}" );
            var d2 = ioc.GetService<IDummy>();
            Console.WriteLine( $"{d2.GetPong()}" );
            var s1 = ioc.GetService<ISnafu>();
            Console.WriteLine($"{s1.GetSnafu()}" );
            var s2 = ioc.GetService<ISnafu>();
            Console.WriteLine($"{s2.GetSnafu()}" );            
            var t1 = ioc.GetService<ITransx>();
            Console.WriteLine($"{t1.GetTransx()}" );
            var t2 = ioc.GetService<ITransx>();
            Console.WriteLine($"{t2.GetTransx()}" );
            var t3 = ioc.GetService<ITransx>();
            Console.WriteLine($"{t3.GetTransx()}" );            
            ReleaseContainer();            
        }
        
        private static void TestTwo()
        {
            Console.WriteLine("\nTestTwo");
            PrepareContainer();            
            var sx1 = ioc.GetService<ISnafu>();
            Console.WriteLine($"{sx1.GetSnafu()}" );
            var dx1 = ioc.GetService<IDummy>();
            Console.WriteLine( $"{dx1.GetPong()}" );
            var dx2 = ioc.GetService<IDummy>();
            Console.WriteLine( $"{dx2.GetPong()}" );
            ReleaseContainer();            
        }
        
        private static void ReleaseContainer()
        {
            // dispose container and services in it
            if(ioc is IDisposable)
            {
                Console.WriteLine("Can dispose stuff !");
                ( (IDisposable)ioc).Dispose();
            }            
        }
    }
}
}}}

=== Example output ===
{{{
Hello World DI!

TestOne
Constructed dummy 37a7cced-15c3-4b33-9eec-55f0fb58ce8c !
Pong 37a7cced-15c3-4b33-9eec-55f0fb58ce8c !
Pong 37a7cced-15c3-4b33-9eec-55f0fb58ce8c !
Constructed snafu 619160b5-6e67-4396-8555-f453bd1ad06f !
Snafu 619160b5-6e67-4396-8555-f453bd1ad06f related with Pong 37a7cced-15c3-4b33-9eec-55f0fb58ce8c !!
Snafu 619160b5-6e67-4396-8555-f453bd1ad06f related with Pong 37a7cced-15c3-4b33-9eec-55f0fb58ce8c !!
Constructed transx 6cf6600a-e622-46fd-8d10-3b6015601911 !
Transx 6cf6600a-e622-46fd-8d10-3b6015601911 !
Constructed transx c666091c-efe9-407f-8659-6c1bdc7e2b7f !
Transx c666091c-efe9-407f-8659-6c1bdc7e2b7f !
Constructed transx 421a63ca-0e93-4656-ba5c-c8909774827c !
Transx 421a63ca-0e93-4656-ba5c-c8909774827c !
Can dispose stuff !
Disposing transx 421a63ca-0e93-4656-ba5c-c8909774827c !
Disposing transx c666091c-efe9-407f-8659-6c1bdc7e2b7f !
Disposing transx 6cf6600a-e622-46fd-8d10-3b6015601911 !
Disposing snafu 619160b5-6e67-4396-8555-f453bd1ad06f !
Disposing dummy 37a7cced-15c3-4b33-9eec-55f0fb58ce8c !

TestTwo
Constructed dummy 7233afd9-9f2e-43a4-ae1a-bc0abba6abc7 !
Constructed snafu 10298883-4f16-4383-b5b7-ce9e5ad90715 !
Snafu 10298883-4f16-4383-b5b7-ce9e5ad90715 related with Pong 7233afd9-9f2e-43a4-ae1a-bc0abba6abc7 !!
Pong 7233afd9-9f2e-43a4-ae1a-bc0abba6abc7 !
Pong 7233afd9-9f2e-43a4-ae1a-bc0abba6abc7 !
Can dispose stuff !
Disposing snafu 10298883-4f16-4383-b5b7-ce9e5ad90715 !
Disposing dummy 7233afd9-9f2e-43a4-ae1a-bc0abba6abc7 !
}}}

== Eager service bean instantiation ==
To instantiate a service/bean before being used else where add it as an argument in the Configure method that belongs to the Startup class. 


== RBAC role based authorization ==
 * https://docs.microsoft.com/en-us/aspnet/core/security/authentication/identity?view=aspnetcore-2.0&tabs=visual-studio%2Caspnetcore2x
 * https://docs.microsoft.com/en-us/aspnet/core/security/authorization/secure-data?view=aspnetcore-2.0
 * https://docs.microsoft.com/en-us/aspnet/core/security/authorization/roles?view=aspnetcore-2.0

Identity is enabled for the application by calling UseAuthentication in the Configure method. Startup.cs in dotnet core to init the services/beans.

In ASP.NET Core MVC, views are .cshtml files that use the C# programming language in Razor markup. 
 * About.cshtml
{{{
@{
    ViewData["Title"] = "About";
}
<h2>@ViewData["Title"].</h2>
<h3>@ViewData["Message"]</h3>
<p>Use this area to provide additional information.</p>
}}} 

 * HomeController.cs
{{{#!highlight csharp
// method About related with About.cshtml
// ViewData["Message"] defined in the method and accessed inside the view in the About.cshtml
public IActionResult About()
{
    ViewData["Message"] = "Your application description page.";

    return View();
    // return explicit view Orders
    // return View("Orders");
    // return both a view and a model
    // return View("Orders", Orders);
}
}}}


View discovery searches for a matching view file in this order:
 * Views/[ControllerName]/[ViewName].cshtml
 * Views/Shared/[ViewName].cshtml


Pass data to views using several approaches:
 * Strongly-typed data: viewmodel
 * Weakly-typed data
   * ViewData (ViewDataAttribute)
   * ViewBag