Add a .NET Core middleware example

Issue: #338

src/GraphQL.GraphiQLCore/GraphQL.GraphiQLCore.csproj

@@ -0,0 +1,20 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+  <PropertyGroup>
+    <TargetFramework>netcoreapp1.1</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\GraphQL\GraphQL.csproj" />
+    <ProjectReference Include="..\GraphQL.StarWars\GraphQL.StarWars.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.AspNetCore" Version="1.1.2" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Folder Include="wwwroot\" />
+  </ItemGroup>
+
+</Project>

src/GraphQL.GraphiQLCore/GraphQLMiddleware.cs

@@ -0,0 +1,79 @@
+using System;
+using System.IO;
+using System.Linq;
+using System.Net;
+using System.Threading.Tasks;
+using GraphQL.Http;
+using Microsoft.AspNetCore.Http;
+using Newtonsoft.Json;
+
+namespace GraphQL.GraphiQLCore
+{
+    public class GraphQLMiddleware
+    {
+        private readonly RequestDelegate _next;
+        private readonly GraphQLSettings _settings;
+        private readonly IDocumentExecuter _executer;
+        private readonly IDocumentWriter _writer;
+
+        public GraphQLMiddleware(
+            RequestDelegate next,
+            GraphQLSettings settings,
+            IDocumentExecuter executer,
+            IDocumentWriter writer)
+        {
+            _next = next;
+            _settings = settings;
+            _executer = executer;
+            _writer = writer;
+        }
+
+        public async Task Invoke(HttpContext context)
+        {
+            if (!IsGraphQLRequest(context))
+            {
+                await _next(context).ConfigureAwait(false);
+                return;
+            }
+
+            await ExecuteAsync(context);
+        }
+
+        private bool IsGraphQLRequest(HttpContext context)
+        {
+            return context.Request.Path.StartsWithSegments(_settings.Path)
+                && string.Equals(context.Request.Method, "POST", StringComparison.OrdinalIgnoreCase);
+        }
+
+        private async Task ExecuteAsync(HttpContext context)
+        {
+            string body;
+            using (var streamReader = new StreamReader(context.Request.Body))
+            {
+                body = await streamReader.ReadToEndAsync().ConfigureAwait(true);
+            }
+
+            var request = JsonConvert.DeserializeObject<GraphQLRequest>(body);
+
+            var result = await _executer.ExecuteAsync(_ =>
+            {
+                _.Schema = _settings.Schema;
+                _.Query = request.Query;
+                _.OperationName = request.OperationName;
+                _.Inputs = request.Variables.ToInputs();
+            });
+
+            await WriteResponseAsync(context, result);
+        }
+
+        private async Task WriteResponseAsync(HttpContext context, ExecutionResult result)
+        {
+            var json = _writer.Write(result);
+
+            context.Response.ContentType = "application/json";
+            context.Response.StatusCode = result.Errors?.Any() == true ? (int)HttpStatusCode.BadRequest : (int)HttpStatusCode.OK;
+
+            await context.Response.WriteAsync(json);
+        }
+    }
+}

src/GraphQL.GraphiQLCore/GraphQLRequest.cs

@@ -0,0 +1,9 @@
+namespace GraphQL.GraphiQLCore
+{
+    public class GraphQLRequest
+    {
+        public string OperationName { get; set; }
+        public string Query { get; set; }
+        public string Variables { get; set; }
+    }
+}

src/GraphQL.GraphiQLCore/GraphQLSettings.cs

@@ -0,0 +1,11 @@
+using GraphQL.Types;
+using Microsoft.AspNetCore.Http;
+
+namespace GraphQL.GraphiQLCore
+{
+    public class GraphQLSettings
+    {
+        public PathString Path { get; set; } = "/graphql";
+        public ISchema Schema { get; set; }
+    }
+}

src/GraphQL.GraphiQLCore/Program.cs

@@ -0,0 +1,20 @@
+using System.IO;
+using Microsoft.AspNetCore.Hosting;
+
+namespace GraphQL.GraphiQLCore
+{
+    public class Program
+    {
+        public static void Main(string[] args)
+        {
+            var host = new WebHostBuilder()
+                .UseKestrel()
+                .UseContentRoot(Directory.GetCurrentDirectory())
+                .UseIISIntegration()
+                .UseStartup<Startup>()
+                .Build();
+
+            host.Run();
+        }
+    }
+}

src/GraphQL.GraphiQLCore/Properties/launchSettings.json

@@ -0,0 +1,27 @@
+{
+  "iisSettings": {
+    "windowsAuthentication": false,
+    "anonymousAuthentication": true,
+    "iisExpress": {
+      "applicationUrl": "http://localhost:49816/",
+      "sslPort": 0
+    }
+  },
+  "profiles": {
+    "IIS Express": {
+      "commandName": "IISExpress",
+      "launchBrowser": true,
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    },
+    "GraphQL.GraphiQLCore": {
+      "commandName": "Project",
+      "launchBrowser": true,
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      },
+      "applicationUrl": "http://localhost:49817"
+    }
+  }
+}

src/GraphQL.GraphiQLCore/Startup.cs

@@ -0,0 +1,42 @@
+using GraphQL.Http;
+using GraphQL.StarWars;
+using GraphQL.StarWars.Types;
+using GraphQL.Types;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+
+namespace GraphQL.GraphiQLCore
+{
+    public class Startup
+    {
+        public void ConfigureServices(IServiceCollection services)
+        {
+            services.AddSingleton<IDocumentExecuter, DocumentExecuter>();
+            services.AddSingleton<IDocumentWriter, DocumentWriter>();
+
+            services.AddSingleton<StarWarsData>();
+            services.AddSingleton<StarWarsQuery>();
+            services.AddSingleton<HumanType>();
+            services.AddSingleton<DroidType>();
+            services.AddSingleton<CharacterInterface>();
+            services.AddSingleton<ISchema>(s => new StarWarsSchema(type => (GraphType) s.GetService(type)));
+        }
+
+        public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
+        {
+            loggerFactory.AddConsole();
+
+            if (env.IsDevelopment())
+            {
+                app.UseDeveloperExceptionPage();
+            }
+
+            app.UseMiddleware<GraphQLMiddleware>(new GraphQLSettings
+            {
+                Schema = app.ApplicationServices.GetService<ISchema>()
+            });
+        }
+    }
+}

src/GraphQL.sln

@@ -1,7 +1,7 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio 15
-VisualStudioVersion = 15.0.26403.3
+VisualStudioVersion = 15.0.26430.6
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{C1C3FFFD-3369-42B1-BE2E-CA10AD9E2ADA}"
 	ProjectSection(SolutionItems) = preProject
@@ -19,6 +19,10 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "GraphQL.StarWars", "GraphQL
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "GraphQL.Tests", "GraphQL.Tests\GraphQL.Tests.csproj", "{65E750AC-4701-45A8-97C0-822B1CC42C1E}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "GraphQL.GraphiQLCore", "GraphQL.GraphiQLCore\GraphQL.GraphiQLCore.csproj", "{487A7A85-31E1-4B1E-BAAA-F8E723AFEE89}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Examples", "Examples", "{F515FCA3-BD5F-485A-8BDE-E3E5E1FE33B6}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -41,8 +45,17 @@ Global
 		{65E750AC-4701-45A8-97C0-822B1CC42C1E}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{65E750AC-4701-45A8-97C0-822B1CC42C1E}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{65E750AC-4701-45A8-97C0-822B1CC42C1E}.Release|Any CPU.Build.0 = Release|Any CPU
+		{487A7A85-31E1-4B1E-BAAA-F8E723AFEE89}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{487A7A85-31E1-4B1E-BAAA-F8E723AFEE89}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{487A7A85-31E1-4B1E-BAAA-F8E723AFEE89}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{487A7A85-31E1-4B1E-BAAA-F8E723AFEE89}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
 	EndGlobalSection
+	GlobalSection(NestedProjects) = preSolution
+		{EE557888-1CD2-4E87-BD87-06834C988B23} = {F515FCA3-BD5F-485A-8BDE-E3E5E1FE33B6}
+		{AE243087-3A7F-4BB3-9CE7-D95B2379C397} = {F515FCA3-BD5F-485A-8BDE-E3E5E1FE33B6}
+		{487A7A85-31E1-4B1E-BAAA-F8E723AFEE89} = {F515FCA3-BD5F-485A-8BDE-E3E5E1FE33B6}
+	EndGlobalSection
 EndGlobal