Add support for lazy initialization of output

src/modules/Elsa.Expressions/Models/ExpressionExecutionContext.cs

@@ -36,9 +36,13 @@ public class ExpressionExecutionContext
     public ExpressionExecutionContext? ParentContext { get; set; }
     public CancellationToken CancellationToken { get; }
 
+    public MemoryBlock GetBlock(Func<MemoryBlockReference> blockReference) => GetBlock(blockReference());
     public MemoryBlock GetBlock(MemoryBlockReference blockReference) => GetMemoryDatumInternal(blockReference) ?? throw new Exception($"Failed to retrieve memory block with reference {blockReference.Id}");
+    public object Get(Func<MemoryBlockReference> blockReference) => Get(blockReference());
     public object Get(MemoryBlockReference blockReference) => GetBlock(blockReference).Value!;
+    public T Get<T>(Func<MemoryBlockReference> blockReference) => Get<T>(blockReference());
     public T Get<T>(MemoryBlockReference blockReference) => (T)Get(blockReference);
+    public void Set(Func<MemoryBlockReference> blockReference, object? value) => Set(blockReference(), value);
 
     public void Set(MemoryBlockReference blockReference, object? value)
     {

src/modules/Elsa.JavaScript/Handlers/ConfigureJavaScriptEngineWithActivityOutput.cs

@@ -33,7 +33,7 @@ public class ConfigureJavaScriptEngineWithActivityOutput : INotificationHandler<
 
             foreach (var property in properties)
             {
-                if (register.TryGetBlock(property.Value.MemoryBlockReference.Id, out var location))
+                if (register.TryGetBlock(property.Value.MemoryBlockReference().Id, out var location))
                     jsActivity[property.Name] = location.Value;
             }
 

src/modules/Elsa.Persistence.EntityFrameworkCore.SqlServer/Extensions/DbContextOptionsBuilderExtensions.cs

@@ -1,12 +1,18 @@
 using Elsa.Persistence.EntityFrameworkCore.Common;
 using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
 
 namespace Elsa.Persistence.EntityFrameworkCore.SqlServer.Extensions;
 
 public static class DbContextOptionsBuilderExtensions
 {
-    public static DbContextOptionsBuilder UseElsaSqlServer(this DbContextOptionsBuilder builder, string connectionString) =>
-        builder.UseSqlServer(connectionString, db => db
-            .MigrationsAssembly(typeof(DbContextOptionsBuilderExtensions).Assembly.GetName().Name)
-            .MigrationsHistoryTable(ElsaDbContextBase.MigrationsHistoryTable, ElsaDbContextBase.ElsaSchema));
+    public static DbContextOptionsBuilder UseElsaSqlServer(this DbContextOptionsBuilder builder, string connectionString, Action<SqlServerDbContextOptionsBuilder>? configure = default) =>
+        builder.UseSqlServer(connectionString, db =>
+        {
+            db
+                .MigrationsAssembly(typeof(DbContextOptionsBuilderExtensions).Assembly.GetName().Name)
+                .MigrationsHistoryTable(ElsaDbContextBase.MigrationsHistoryTable, ElsaDbContextBase.ElsaSchema);
+            
+            configure?.Invoke(db);
+        });
 }

src/modules/Elsa.Quartz/Elsa.Quartz.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
-    <Import Project="..\..\..\common.props"/>
-    <Import Project="..\..\..\configureawait.props"/>
+    <Import Project="..\..\..\common.props" />
+    <Import Project="..\..\..\configureawait.props" />
 
     <PropertyGroup>
         <TargetFramework>net6.0</TargetFramework>

src/modules/Elsa.Quartz/Extensions/ModuleExtensions.cs

@@ -0,0 +1,14 @@
+using Elsa.Features.Extensions;
+using Elsa.Features.Services;
+using Elsa.Quartz.Features;
+
+namespace Elsa.Quartz.Extensions;
+
+public static class ModuleExtensions
+{
+    public static IModule UseQuartz(this IModule module, Action<QuartzFeature>? configure = default)
+    {
+        module.Use(configure);
+        return module;
+    }
+}

src/modules/Elsa.Quartz/Extensions/SchedulingFeatureExtensions.cs

@@ -0,0 +1,15 @@
+using Elsa.Features.Extensions;
+using Elsa.Features.Services;
+using Elsa.Quartz.Features;
+using Elsa.Scheduling.Features;
+
+namespace Elsa.Quartz.Extensions;
+
+public static class SchedulingFeatureExtensions
+{
+    public static SchedulingFeature UseQuartzScheduling(this SchedulingFeature scheduling)
+    {
+        scheduling.Module.Use<QuartzSchedulerFeature>();
+        return scheduling;
+    }
+}

src/modules/Elsa.Telnyx/Activities/Dial.cs

@@ -1,4 +1,5 @@
-using Elsa.Telnyx.Client.Models;
+using Elsa.Telnyx.Bookmarks;
+using Elsa.Telnyx.Client.Models;
 using Elsa.Telnyx.Client.Services;
 using Elsa.Telnyx.Exceptions;
 using Elsa.Telnyx.Extensions;
@@ -8,6 +9,7 @@ using Elsa.Workflows.Core;
 using Elsa.Workflows.Core.Activities.Flowchart.Attributes;
 using Elsa.Workflows.Core.Attributes;
 using Elsa.Workflows.Core.Models;
+using Elsa.Workflows.Core.Services;
 using Elsa.Workflows.Management.Models;
 using Microsoft.Extensions.Options;
 
@@ -17,8 +19,7 @@ namespace Elsa.Telnyx.Activities;
 /// Dial a number or SIP URI.
 /// </summary>
 [Activity(Constants.Namespace, "Dial a number or SIP URI.", Kind = ActivityKind.Task)]
-[FlowNode("Answered", "Hangup")]
-public class Dial : ActivityBase
+public abstract class DialBase : ActivityBase
 {
     [Input(Description = "The DID or SIP URI to dial out and bridge to the given call.")]
     public Input<string?>? To { get; set; } = default!;
@@ -33,7 +34,7 @@ public class Dial : ActivityBase
     [Input(
         Description = "Enables Answering Machine Detection.",
         UIHint = InputUIHints.Dropdown,
-        Options = new[] { "disabled", "detect", "detect_beep", "detect_words", "greeting_end" },
+        Options = new[] { "disabled", "detect", "detect_beep", "detect_words", "greeting_end", "premium" },
         DefaultValue = "disabled")]
     public Input<string?>? AnsweringMachineDetection { get; set; } = new("disabled");
 
@@ -71,16 +72,16 @@ public class Dial : ActivityBase
         }
     }
 
-    private async ValueTask HandleAnsweredAsync(ActivityExecutionContext context) => await context.CompleteActivityWithOutcomesAsync("Answered");
-
-    private async ValueTask HandleHangupAsync(ActivityExecutionContext context) => await context.CompleteActivityWithOutcomesAsync("Hangup"); 
-
     private void HandleMachineGreetingEnded(ActivityExecutionContext context, CallMachineGreetingEndedBase payload)
     {
         context.Set(MachineDetectionResult, payload.Result);
-        context.CreateBookmark();
+        context.CreateBookmark(new WebhookEventBookmarkPayload(WebhookEventTypes.CallAnswered), ResumeAsync);
+        context.CreateBookmark(new WebhookEventBookmarkPayload(WebhookEventTypes.CallHangup), ResumeAsync);
     }
 
+    protected abstract ValueTask HandleAnsweredAsync(ActivityExecutionContext context);
+    protected abstract ValueTask HandleHangupAsync(ActivityExecutionContext context);
+
     private async Task DialAsync(ActivityExecutionContext context)
     {
         var telnyxOptions = context.GetRequiredService<IOptions<TelnyxOptions>>().Value;
@@ -100,8 +101,33 @@ public class Dial : ActivityBase
             AnsweringMachineDetection.Get(context),
             ClientState: clientState
         );
-            
+
         var telnyxClient = context.GetRequiredService<ITelnyxClient>();
         await telnyxClient.Calls.DialAsync(request, context.CancellationToken);
     }
+}
+
+[FlowNode("Answered", "Hangup")]
+public class FlowDial : DialBase
+{
+    protected override async ValueTask HandleAnsweredAsync(ActivityExecutionContext context) => await context.CompleteActivityWithOutcomesAsync("Answered");
+    protected override async ValueTask HandleHangupAsync(ActivityExecutionContext context) => await context.CompleteActivityWithOutcomesAsync("Hangup");
+}
+
+public class Dial : DialBase
+{
+    [Port] public IActivity? Answered { get; set; }
+    [Port] public IActivity? Hangup { get; set; }
+
+    protected override ValueTask HandleAnsweredAsync(ActivityExecutionContext context)
+    {
+        context.ScheduleActivity(Answered);
+        return ValueTask.CompletedTask;
+    }
+
+    protected override ValueTask HandleHangupAsync(ActivityExecutionContext context)
+    {
+        context.ScheduleActivity(Hangup);
+        return ValueTask.CompletedTask;
+    }
 }

src/modules/Elsa.Telnyx/WebhookEventTypes.cs

@@ -10,6 +10,7 @@ internal static class WebhookEventTypes
     public const string CallInitiated = "call.initiated";
     public const string CallMachineGreetingEnded = "call.machine.greeting.ended";
     public const string CallMachinePremiumGreetingEnded = "call.machine.premium.greeting.ended";
+    public const string CallMachineDetectionEnded = "call.machine.detection.ended";
     public const string CallMachinePremiumDetectionEnded = "call.machine.premium.detection.ended";
     public const string CallPlaybackStarted = "call.playback.started";
     public const string CallPlaybackEnded = "call.playback.ended";

src/modules/Elsa.Workflows.Core/Activities/ForEach.cs

@@ -95,8 +95,8 @@ public class ForEach<T> : ForEach
     [Input]
     public new Input<ICollection<T>> Items
     {
-        get => new(base.Items.Expression, base.Items.MemoryBlockReference);
-        set => base.Items = new Input<ICollection<object>>(value.Expression, value.MemoryBlockReference);
+        get => new(base.Items.Expression, base.Items.MemoryBlockReference());
+        set => base.Items = new Input<ICollection<object>>(value.Expression, value.MemoryBlockReference());
     }
 
     public new Output<T?> CurrentValue

src/modules/Elsa.Workflows.Core/Extensions/ActivityExecutionContextExtensions.cs

@@ -64,7 +64,7 @@ public static class ActivityExecutionContextExtensions
 
         foreach (var input in assignedInputs)
         {
-            var memoryReference = input.MemoryBlockReference;
+            var memoryReference = input.MemoryBlockReference();
             var value = await evaluator.EvaluateAsync(input, expressionExecutionContext);
             memoryReference.Set(context, value);
         }
@@ -96,9 +96,9 @@ public static class ActivityExecutionContextExtensions
         var evaluator = context.GetRequiredService<IExpressionEvaluator>();
         var expressionExecutionContext = context.ExpressionExecutionContext;
 
-        var locationReference = input.MemoryBlockReference;
+        var memoryBlockReference = input.MemoryBlockReference();
         var value = await evaluator.EvaluateAsync(input, expressionExecutionContext);
-        locationReference.Set(context, value);
+        memoryBlockReference.Set(context, value);
 
         return input;
     }
@@ -151,9 +151,9 @@ public static class ActivityExecutionContextExtensions
     public static async Task<T?> EvaluateAsync<T>(this ActivityExecutionContext context, Input<T> input)
     {
         var evaluator = context.GetRequiredService<IExpressionEvaluator>();
-        var locationReference = input.MemoryBlockReference;
+        var memoryBlockReference = input.MemoryBlockReference();
         var value = await evaluator.EvaluateAsync(input, context.ExpressionExecutionContext);
-        locationReference.Set(context, value);
+        memoryBlockReference.Set(context, value);
         return value;
     }
 

src/modules/Elsa.Workflows.Core/Extensions/ExpressionExecutionContextExtensions.cs

@@ -45,6 +45,6 @@ public static class ExpressionExecutionContextExtensions
 
     public static void Set(this ExpressionExecutionContext context, Output? output, object? value)
     {
-        if(output != null) context.Set(output.MemoryBlockReference, value);
+        if(output != null) context.Set(output.MemoryBlockReference(), value);
     }
 }

src/modules/Elsa.Workflows.Core/Implementations/IdentityGraphService.cs

@@ -36,24 +36,33 @@ public class IdentityGraphService : IIdentityGraphService
     private void AssignInputOutputs(IActivity activity)
     {
         var inputs = activity.GetInputs();
-        var assignedInputs = inputs.Where(x => x.MemoryBlockReference != null! && x.MemoryBlockReference.Id == null!).ToList();
+        
+        var assignedInputs = inputs.Where(x =>
+        {
+            var memoryBlockReference = x.MemoryBlockReference();
+            return memoryBlockReference.Id == null!;
+        }).ToList();
+        
         var seed = 0;
 
         foreach (var input in assignedInputs)
         {
-            var locationReference = input.MemoryBlockReference;
-
+            var locationReference = input.MemoryBlockReference();
             locationReference.Id = $"{activity.Id}:input-{++seed}";
         }
 
         seed = 0;
         var outputs = activity.GetOutputs();
-        var assignedOutputs = outputs.Where(x => x.Value.MemoryBlockReference != null! && x.Value.MemoryBlockReference.Id == null!).ToList();
+        
+        var assignedOutputs = outputs.Where(x =>
+        {
+            var memoryBlockReference = x.Value.MemoryBlockReference();
+            return memoryBlockReference != null! && memoryBlockReference.Id == null!;
+        }).ToList();
 
         foreach (var output in assignedOutputs)
         {
-            var memoryReference = output.Value.MemoryBlockReference;
-
+            var memoryReference = output.Value.MemoryBlockReference();
             memoryReference.Id = $"{activity.Id}:output-{++seed}";
         }
     }

src/modules/Elsa.Workflows.Core/Models/ActivityExecutionContext.cs

@@ -190,7 +190,7 @@ public class ActivityExecutionContext
     public T? GetService<T>() where T : notnull => WorkflowExecutionContext.GetService<T>();
     public IEnumerable<T> GetServices<T>() where T : notnull => WorkflowExecutionContext.GetServices<T>();
     public object? GetService(Type serviceType) => WorkflowExecutionContext.GetService(serviceType);
-    public T? Get<T>(Input<T>? input) => input == null ? default : Get<T>(input.MemoryBlockReference);
+    public T? Get<T>(Input<T>? input) => input == null ? default : Get<T>(input.MemoryBlockReference());
 
     public object? Get(MemoryBlockReference blockReference)
     {

src/modules/Elsa.Workflows.Core/Models/Argument.cs

@@ -4,14 +4,18 @@ namespace Elsa.Workflows.Core.Models;
 
 public abstract class Argument
 {
-    protected Argument(){}
-    
-    protected Argument(MemoryBlockReference memoryBlockReference /*, Func<object?, object?>? valueConverter = default*/)
+    protected Argument()
     {
-        MemoryBlockReference = memoryBlockReference;
-        //ValueConverter = valueConverter;
     }
 
-    public MemoryBlockReference MemoryBlockReference { get; set; } = default!;
-    //public Func<object?, object?>? ValueConverter { get; set; }
+    protected Argument(MemoryBlockReference memoryBlockReference) : this(() => memoryBlockReference)
+    {
+    }
+    
+    protected Argument(Func<MemoryBlockReference> memoryBlockReference)
+    {
+        MemoryBlockReference = memoryBlockReference;
+    }
+
+    public Func<MemoryBlockReference> MemoryBlockReference { get; set; } = default!;
 }

src/modules/Elsa.Workflows.Core/Models/Input.cs

@@ -43,7 +43,7 @@ public class Input<T> : Input
     {
     }
     
-    public Input(Output output) : base(new OutputExpression(output), output.MemoryBlockReference, typeof(T))
+    public Input(Output output) : base(new OutputExpression(output), output.MemoryBlockReference(), typeof(T))
     {
     }
 

src/modules/Elsa.Workflows.Core/Models/Output.cs

@@ -8,11 +8,13 @@ public class Output : Argument
     {
     }
 
-    public Output(MemoryBlockReference locationBlockReference) : base(locationBlockReference)
+    public Output(MemoryBlockReference memoryBlockReference) : base(memoryBlockReference)
+    {
+    }
+    
+    public Output(Func<MemoryBlockReference> memoryBlockReference) : base(memoryBlockReference)
     {
     }
-
-    //public ICollection<MemoryReference> Targets { get; } = new List<MemoryReference>();
 }
 
 public class Output<T> : Output
@@ -21,7 +23,11 @@ public class Output<T> : Output
     {
     }
     
-    public Output(MemoryBlockReference locationBlockReference) : base(locationBlockReference)
+    public Output(MemoryBlockReference memoryBlockReference) : base(memoryBlockReference)
+    {
+    }
+    
+    public Output(Func<MemoryBlockReference> memoryBlockReference) : base(memoryBlockReference)
     {
     }
 }

src/modules/Elsa.Workflows.Management/Serialization/Converters/OutputJsonConverter.cs

@@ -46,7 +46,7 @@ public class OutputJsonConverter<T> : JsonConverter<Output<T>?>
             Type = valueTypeAlias,
             MemoryReference = value == null ? null : new
             {
-                Id = value.MemoryBlockReference.Id
+                Id = value.MemoryBlockReference().Id
             }
         };
 

src/modules/Elsa.Workflows.Runtime/Implementations/TriggerIndexer.cs

@@ -165,7 +165,7 @@ public class TriggerIndexer : ITriggerIndexer
         // Evaluate activity inputs before requesting trigger data.
         foreach (var input in assignedInputs)
         {
-            var locationReference = input.MemoryBlockReference;
+            var locationReference = input.MemoryBlockReference();
 
             try
             {

src/modules/Elsa.Workflows.Runtime/Middleware/PersistWorkflowExecutionLogMiddleware.cs

@@ -7,7 +7,7 @@ using Elsa.Workflows.Runtime.Services;
 namespace Elsa.Workflows.Runtime.Middleware;
 
 /// <summary>
-/// Takes care of persisting a workflow instance after workflow execution.
+/// Takes care of persisting workflow execution log entries.
 /// </summary>
 public class PersistWorkflowExecutionLogMiddleware : WorkflowExecutionMiddleware
 {

src/samples/console/Elsa.Samples.Composition/Activities/AskAge.cs

@@ -4,7 +4,6 @@ using Elsa.Workflows.Core.Models;
 
 public class AskAge : Composite<int>
 {
-    private readonly WriteLine _prompt = new();
     private readonly Variable<string> _age = new();
 
     public Input<string> Prompt { get; set; } = new("Please tell me your age:");
@@ -16,17 +15,12 @@ public class AskAge : Composite<int>
             Variables = { _age },
             Activities =
             {
-                _prompt,
+                new WriteLine(context => Prompt.Get(context)),
                 new ReadLine(_age)
             }
         };
     }
 
-    protected override void ConfigureActivities(ActivityExecutionContext context)
-    {
-        _prompt.Text = Prompt;
-    }
-
     protected override void OnCompleted(ActivityExecutionContext context, ActivityExecutionContext childContext)
     {
         var age = _age.Get<int>(context);

src/samples/console/Elsa.Samples.Composition/Activities/AskDetails.cs

@@ -0,0 +1,42 @@
+using Elsa.Workflows.Core;
+using Elsa.Workflows.Core.Activities;
+using Elsa.Workflows.Core.Models;
+
+public class AskDetails : Composite<Person>
+{
+    private readonly Variable<string> _name = new();
+    private readonly Variable<int> _age = new();
+
+    public Input<string> NamePrompt { get; set; } = new("Please tell me your name:");
+    public Input<string> AgePrompt { get; set; } = new("Please tell me your age:");
+
+    public AskDetails()
+    {
+        Root = new Sequence
+        {
+            Variables = { _name, _age },
+            Activities =
+            {
+                new AskName
+                {
+                    Prompt = new Input<string>(context => NamePrompt.Get(context)),
+                    Result = new Output(() => _name)
+                },
+                new AskAge
+                {
+                    Prompt = new Input<string>(context => AgePrompt.Get(context)),
+                    Result = new Output(() => _age)
+                }
+            }
+        };
+    }
+
+    protected override void OnCompleted(ActivityExecutionContext context, ActivityExecutionContext childContext)
+    {
+        var name = _name.Get<string>(context)!;
+        var age = _age.Get<int>(context);
+        var person = new Person(name, age);
+        
+        context.Set(Result, person);
+    }
+}

src/samples/console/Elsa.Samples.Composition/Activities/AskName.cs

@@ -0,0 +1,29 @@
+using Elsa.Workflows.Core;
+using Elsa.Workflows.Core.Activities;
+using Elsa.Workflows.Core.Models;
+
+public class AskName : Composite<string>
+{
+    private readonly Variable<string> _name = new();
+
+    public Input<string> Prompt { get; set; } = new("Please tell me your name:");
+
+    public AskName()
+    {
+        Root = new Sequence
+        {
+            Variables = { _name },
+            Activities =
+            {
+                new WriteLine(context => Prompt.Get(context)),
+                new ReadLine(_name)
+            }
+        };
+    }
+
+    protected override void OnCompleted(ActivityExecutionContext context, ActivityExecutionContext childContext)
+    {
+        var name = _name.Get<string>(context);
+        context.Set(Result, name);
+    }
+}

src/samples/console/Elsa.Samples.Composition/Models/Person.cs

@@ -0,0 +1 @@
+public record Person(string Name, int Age);

src/samples/console/Elsa.Samples.Composition/Program.cs

@@ -14,20 +14,25 @@ services.AddElsa();
 var serviceProvider = services.BuildServiceProvider();
 
 // Declare a workflow variable for use in the workflow.
-var ageVariable = new Variable<int>();
+var personVariable = new Variable<Person>();
 
 // Declare a workflow.
 var workflow = new Sequence
 {
-    Variables = { ageVariable },
+    Variables = { personVariable },
     Activities =
     {
-        new AskAge
+        new AskDetails()
         {
-            Prompt = new Input<string>("What's your age?"),
-            Result = new Output(ageVariable)
+            NamePrompt = new Input<string>("What's your name?"),
+            AgePrompt = new Input<string>("What's your age?"),
+            Result = new Output(personVariable)
         },
-        new WriteLine(context => $"The age you told me is: {ageVariable.Get(context)}")
+        new WriteLine(context =>
+        {
+            var person = personVariable.Get(context)!;
+            return $"Your name is {person.Name} and you are {person.Age} years old.";
+        })
     }
 };