Integrate SendGrid with HttpClientFactory (#922)

* Integrate SendGrid with HttpClientFactory

- Introduce new SendGrid.Extensions.DependencyInjection package for HttpClientFactory integrations

* Update SendGrid.Tests

- Update NuGet packages
- Cleanup Properties

* Add Solution Items

* Renamed `Example.cs` to `Program.cs`

- `Program.cs` is the convention of C# console application entry point

* Build .NET Framework libraries on Linux without Mono

- https://andrewlock.net/using-reference-assemblies-to-build-net-framework-libararies-on-linux-without-mono/

* Simplify Examples

- Upgrade to SDK style csproj
- Code cleanup

* Simplify Makefile

* Update README.md

- Add `SendGrid.Extensions.DependencyInjection` usage
- Fixes typo
- Fixes Markdown syntax warnings
- Simplify examples

* Use .NET Core CLI for *.nupkg deployment

- https://docs.microsoft.com/dotnet/core/tools/dotnet-nuget-push

Author: akunzai

.travis.yml

@@ -3,18 +3,11 @@ dotnet: 2.1.803
 solution: SendGrid.sln
 os: linux
 dist: bionic
-mono: latest
+mono: none
 
 services:
   - docker
 
-before_install:
-  - mkdir -p .nuget
-  - wget -O .nuget/nuget.exe https://dist.nuget.org/win-x86-commandline/latest/nuget.exe
-
-env:
-  - FrameworkPathOverride=/usr/lib/mono/4.5/
-
 script:
   - make test-docker
   - make release
@@ -25,7 +18,7 @@ after_success:
 deploy:
   skip_cleanup: true
   provider: script
-  script: nuget push ./src/SendGrid/bin/Release/SendGrid.*.nupkg -ApiKey $NUGET_API_KEY -Source https://api.nuget.org/v3/index.json
+  script: dotnet nuget push **/*.nupkg -k $NUGET_API_KEY -s https://api.nuget.org/v3/index.json
   on:
     branch: master
     tags: true

ExampleCoreProject/ExampleCoreProject.csproj

@@ -1,23 +1,28 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp1.0</TargetFramework>
-    <AssemblyName>ExampleCoreProject</AssemblyName>
+    <TargetFramework>netcoreapp2.1</TargetFramework>
     <OutputType>Exe</OutputType>
-    <PackageId>ExampleCoreProject</PackageId>
-    <RuntimeFrameworkVersion>1.0.4</RuntimeFrameworkVersion>
-    <GenerateAssemblyConfigurationAttribute>false</GenerateAssemblyConfigurationAttribute>
-    <GenerateAssemblyCompanyAttribute>false</GenerateAssemblyCompanyAttribute>
-    <GenerateAssemblyProductAttribute>false</GenerateAssemblyProductAttribute>
+    <IsPackable>false</IsPackable>
   </PropertyGroup>
 
   <ItemGroup>
-    <ProjectReference Include="..\src\SendGrid\SendGrid.csproj" />
+    <None Update="appsettings.json">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
+    <None Update="appsettings.*.json">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
   </ItemGroup>
 
-  <ItemGroup Condition=" '$(TargetFramework)' == 'netcoreapp1.0' ">
-    <PackageReference Include="Newtonsoft.Json" Version="9.0.1" />
-    <PackageReference Include="System.Net.Http" Version="4.3.2" />
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="3.1.4" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="3.1.4" />
+    <PackageReference Include="Microsoft.Extensions.Http" Version="3.1.4" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\src\SendGrid.Extensions.DependencyInjection\SendGrid.Extensions.DependencyInjection.csproj" />
   </ItemGroup>
 
 </Project>

ExampleCoreProject/Program.cs

@@ -0,0 +1,57 @@
+using System;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using SendGrid;
+using SendGrid.Extensions.DependencyInjection;
+using SendGrid.Helpers.Mail;
+
+namespace Example
+{
+    internal class Program
+    {
+        private static IConfiguration Configuration { get; set; }
+
+        private static async Task Main()
+        {
+            var env = Environment.GetEnvironmentVariable("DOTNET_ENVIRONMENT") ?? "Production";
+            Configuration = new ConfigurationBuilder()
+                    .AddJsonFile("appsettings.json", optional: true)
+                    .AddJsonFile($"appsettings.{env}.json", optional: true)
+                    .Build();
+            var services = ConfigureServices(new ServiceCollection()).BuildServiceProvider();
+            var client = services.GetRequiredService<ISendGridClient>();
+            var from = new EmailAddress(Configuration.GetValue("SendGrid:From", "[email protected]"), "Example User");
+            var to = new EmailAddress(Configuration.GetValue("SendGrid:To", "[email protected]"), "Example User");
+            var msg = new SendGridMessage
+            {
+                From = from,
+                Subject = "Sending with Twilio SendGrid is Fun"
+            };
+            msg.AddContent(MimeType.Text, "and easy to do anywhere, even with C#");
+            msg.AddTo(to);
+            if (Configuration.GetValue("SendGrid:SandboxMode", false))
+            {
+                msg.MailSettings = new MailSettings
+                {
+                    SandboxMode = new SandboxMode
+                    {
+                        Enable = true
+                    }
+                };
+            }
+            Console.WriteLine($"Sending email with payload: \n{msg.Serialize()}");
+            var response = await client.SendEmailAsync(msg).ConfigureAwait(false);
+
+            Console.WriteLine($"Response: {response.StatusCode}");
+            Console.WriteLine(response.Headers);
+        }
+
+        private static IServiceCollection ConfigureServices(IServiceCollection services)
+        {
+            services.AddSendGrid(options => { options.ApiKey = Environment.GetEnvironmentVariable("SENDGRID_API_KEY") ?? Configuration["SendGrid:ApiKey"]; });
+
+            return services;
+        }
+    }
+}