Add activity output example

Samples.sln

@@ -87,6 +87,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Elsa.Persistence.DocumentDb
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Sample16", "src\samples\Sample16\Sample16.csproj", "{DFE72CF4-C77C-4932-A00F-A8D325E603CE}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Sample17", "src\samples\Sample17\Sample17.csproj", "{8854DF17-D566-49C9-8210-68AB8F5659FA}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -221,6 +223,10 @@ Global
 		{DFE72CF4-C77C-4932-A00F-A8D325E603CE}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{DFE72CF4-C77C-4932-A00F-A8D325E603CE}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{DFE72CF4-C77C-4932-A00F-A8D325E603CE}.Release|Any CPU.Build.0 = Release|Any CPU
+		{8854DF17-D566-49C9-8210-68AB8F5659FA}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{8854DF17-D566-49C9-8210-68AB8F5659FA}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{8854DF17-D566-49C9-8210-68AB8F5659FA}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{8854DF17-D566-49C9-8210-68AB8F5659FA}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -263,6 +269,7 @@ Global
 		{79E85459-EF54-44D6-9508-1E68B8238D00} = {B43B546E-23F3-46E8-ACB7-D04F05CDA180}
 		{8C51A528-F9B5-464E-AAD1-1ADC44697085} = {600C4AE0-0585-4181-9CEC-2BB43430C713}
 		{DFE72CF4-C77C-4932-A00F-A8D325E603CE} = {5E5E1E84-DDBC-40D6-B891-0D563A15A44A}
+		{8854DF17-D566-49C9-8210-68AB8F5659FA} = {5E5E1E84-DDBC-40D6-B891-0D563A15A44A}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {8B0975FD-7050-48B0-88C5-48C33378E158}

src/samples/Sample17/Activities/CreateDocument.cs

@@ -0,0 +1,38 @@
+using System.Threading;
+using System.Threading.Tasks;
+using Elsa.Expressions;
+using Elsa.Extensions;
+using Elsa.Results;
+using Elsa.Services;
+using Elsa.Services.Models;
+using Sample17.Models;
+
+namespace Sample17.Activities
+{
+    public class CreateDocument : Activity
+    {
+        private readonly IWorkflowExpressionEvaluator expressionEvaluator;
+
+        public CreateDocument(IWorkflowExpressionEvaluator expressionEvaluator)
+        {
+            this.expressionEvaluator = expressionEvaluator;
+        }
+        
+        public WorkflowExpression<string> TitleExpression
+        {
+            get => GetState<WorkflowExpression<string>>();
+            set => SetState(value);
+        }
+
+        protected override async Task<ActivityExecutionResult> OnExecuteAsync(
+            WorkflowExecutionContext context,
+            CancellationToken cancellationToken)
+        {
+            var title = await expressionEvaluator.EvaluateAsync(TitleExpression, context, cancellationToken);
+            var document = new Document { Title = title};
+
+            Output["Document"] = document;
+            return Done();
+        }
+    }
+}

src/samples/Sample17/CreateDocumentWorkflow.cs

@@ -0,0 +1,20 @@
+using Elsa.Activities.Console.Activities;
+using Elsa.Expressions;
+using Elsa.Services;
+using Elsa.Services.Models;
+using Sample17.Activities;
+
+namespace Sample17
+{
+    public class CreateDocumentWorkflow : IWorkflow
+    {
+        public void Build(IWorkflowBuilder builder)
+        {
+            builder
+                .StartWith<WriteLine>(x => x.TextExpression = new LiteralExpression("Enter a title"))
+                .Then<ReadLine>(id: "DocumentTitleInput")
+                .Then<CreateDocument>(x => x.TitleExpression = new JavaScriptExpression<string>("DocumentTitleInput.Input"), id: "CreateDocument")
+                .Then<WriteLine>(x => x.TextExpression = new JavaScriptExpression<string>("`A new document was created with title \"${CreateDocument.Document.Title}\"`"));
+        }
+    }
+}

src/samples/Sample17/Models/Document.cs

@@ -0,0 +1,7 @@
+namespace Sample17.Models
+{
+    public class Document
+    {
+        public string Title { get; set; }
+    }
+}

src/samples/Sample17/Program.cs

@@ -0,0 +1,30 @@
+using System;
+using System.Threading.Tasks;
+using Elsa.Activities.Console.Extensions;
+using Elsa.Services;
+using Microsoft.Extensions.DependencyInjection;
+using Sample17.Activities;
+
+namespace Sample17
+{
+    internal static class Program
+    {
+        private static async Task Main(string[] args)
+        {
+            var services = BuildServices();
+            var workflowInvoker = services.GetRequiredService<IWorkflowInvoker>();
+
+            await workflowInvoker.StartAsync<CreateDocumentWorkflow>();
+        }
+        
+        private static IServiceProvider BuildServices()
+        {
+            return new ServiceCollection()
+                .AddWorkflows()
+                .AddWorkflow<CreateDocumentWorkflow>()
+                .AddConsoleActivities()
+                .AddActivity<CreateDocument>()
+                .BuildServiceProvider();
+        }
+    }
+}

src/samples/Sample17/Sample17.csproj

@@ -0,0 +1,15 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <OutputType>Exe</OutputType>
+        <TargetFramework>netcoreapp3.0</TargetFramework>
+        <LangVersion>latest</LangVersion>
+    </PropertyGroup>
+
+    <ItemGroup>
+        <ProjectReference Include="..\..\activities\Elsa.Activities.Console\Elsa.Activities.Console.csproj" />
+        <ProjectReference Include="..\..\core\Elsa.Core\Elsa.Core.csproj" />
+        <ProjectReference Include="..\..\persistence\Elsa.Persistence.MongoDb\Elsa.Persistence.MongoDb.csproj" />
+    </ItemGroup>
+
+</Project>