Various API enhancements

src/core/Elsa.Core/Activities/Console/ReadLine.cs

@@ -3,19 +3,17 @@ using Elsa.Models;
 
 namespace Elsa.Activities.Console;
 
-public class ReadLine : Activity
+public class ReadLine : Activity<string>
 {
     public ReadLine()
     {
     }
 
-    public ReadLine(Variable variable, Func<object?, object?>? valueConverter = default) => Output = new Output<string?>(variable, valueConverter);
-
-    [Output] public Output<string?>? Output { get; set; }
+    public ReadLine(Variable variable, Func<object?, object?>? valueConverter = default) => Result = new Output<string?>(variable, valueConverter);
 
     protected override void Execute(ActivityExecutionContext context)
     {
         var text = System.Console.ReadLine();
-        context.Set(Output, text);
+        context.Set(Result, text);
     }
 }

src/core/Elsa.Core/Activities/ControlFlow/For.cs

@@ -55,7 +55,7 @@ public class For : Activity
 
         if (loop)
         {
-            context.ScheduleActivity(iterateNode, OnChildComplete);
+            context.SubmitActivity(iterateNode, OnChildComplete);
 
             // Update loop variable.
             CurrentValue.Set(context.ExpressionExecutionContext, currentValue);

src/core/Elsa.Core/Activities/ControlFlow/ForEach.cs

@@ -32,7 +32,7 @@ public class ForEach : Activity
         CurrentValue.Set(context, currentItem);
 
         if (Body != null)
-            context.ScheduleActivity(Body, OnChildCompleted);
+            context.SubmitActivity(Body, OnChildCompleted);
 
         // Increment index.
         context.UpdateProperty<int>(CurrentIndexProperty, x => x + 1);

src/core/Elsa.Core/Activities/ControlFlow/If.cs

@@ -6,6 +6,14 @@ namespace Elsa.Activities.ControlFlow;
 
 public class If : Activity
 {
+    public If()
+    {
+    }
+
+    public If(Input<bool> condition) => Condition = condition;
+    public If(Func<ExpressionExecutionContext, bool> condition) => Condition = new Input<bool>(condition);
+    public If(Func<bool> condition) => Condition = new Input<bool>(condition);
+
     [Input] public Input<bool> Condition { get; set; } = new(new Literal<bool>(false));
     [Outbound] public IActivity? Then { get; set; }
     [Outbound] public IActivity? Else { get; set; }
@@ -16,7 +24,7 @@ public class If : Activity
         var nextNode = result ? Then : Else;
 
         if (nextNode != null)
-            context.ScheduleActivity(nextNode, OnChildCompletedAsync);
+            context.SubmitActivity(nextNode, OnChildCompletedAsync);
     }
 
     private ValueTask OnChildCompletedAsync(ActivityExecutionContext context, ActivityExecutionContext childContext)

src/core/Elsa.Core/Activities/ControlFlow/ParallelForEach.cs

@@ -26,7 +26,7 @@ public class ParallelForEach<T> : Activity
             };
             
             // Schedule a body of work for each item.
-            context.ScheduleActivity(Body, OnChildCompleted, new[]{localVariable});
+            context.SubmitActivity(Body, OnChildCompleted, new[]{localVariable});
         }
     }
 

src/core/Elsa.Core/Activities/ControlFlow/Switch.cs

@@ -21,12 +21,12 @@ public class Switch : Activity
         if (matchingCase != null)
         {
             if (matchingCase.Activity != null)
-                context.ScheduleActivity(matchingCase.Activity);
+                context.SubmitActivity(matchingCase.Activity);
             return;
         }
 
         if (Default != null)
-            context.ScheduleActivity(Default);
+            context.SubmitActivity(Default);
     }
 
     private async Task<SwitchCase?> FindMatchingCaseAsync(ExpressionExecutionContext context)

src/core/Elsa.Core/Activities/ControlFlow/While.cs

@@ -14,7 +14,7 @@ public class While : Activity
         var loop = context.Get(Condition);
             
         if(loop)
-            context.ScheduleActivity(Body, OnBodyCompleted);
+            context.SubmitActivity(Body, OnBodyCompleted);
     }
 
     private async ValueTask OnBodyCompleted(ActivityExecutionContext context, ActivityExecutionContext childContext)
@@ -22,6 +22,6 @@ public class While : Activity
         var loop = await context.EvaluateAsync(Condition);
             
         if(loop)
-            context.ScheduleActivity(Body, OnBodyCompleted);
+            context.SubmitActivity(Body, OnBodyCompleted);
     }
 }

src/core/Elsa.Core/Activities/Primitives/Inline.cs

@@ -0,0 +1,85 @@
+using Elsa.Models;
+
+namespace Elsa.Activities.Primitives;
+
+/// <summary>
+/// Represents an inline code activity that can be used to execute arbitrary .NET code from a workflow.
+/// </summary>
+public class Inline : Activity
+{
+    private readonly Func<ActivityExecutionContext, ValueTask> _activity;
+
+    public Inline(Func<ActivityExecutionContext, ValueTask> activity) => _activity = activity;
+
+    public Inline(Func<ValueTask> activity) : this(_ => activity())
+    {
+    }
+
+    public Inline(Action<ActivityExecutionContext> activity) : this(c =>
+    {
+        activity(c);
+        return new ValueTask();
+    })
+    {
+    }
+
+    public Inline(Action activity) : this(c =>
+    {
+        activity();
+        return new ValueTask();
+    })
+    {
+    }
+
+    protected override async ValueTask ExecuteAsync(ActivityExecutionContext context) => await _activity(context);
+
+    public static Inline From(Func<ActivityExecutionContext, ValueTask> activity) => new(activity);
+    public static Inline From(Func<ValueTask> activity) => new(activity);
+    public static Inline From(Action<ActivityExecutionContext> activity) => new(activity);
+    public static Inline From(Action activity) => new(activity);
+
+    public static Inline<T> From<T>(Func<ActivityExecutionContext, ValueTask<T>> activity) => new(activity);
+    public static Inline<T> From<T>(Func<ValueTask<T>> activity) => new(activity);
+    public static Inline<T> From<T>(Func<ActivityExecutionContext, T> activity) => new(activity);
+    public static Inline<T> From<T>(Func<T> activity) => new(activity);
+}
+
+/// <summary>
+/// Represents an inline code activity that can be used to execute arbitrary .NET code from a workflow and return a value.
+/// </summary>
+public class Inline<T> : Activity<T>
+{
+    private readonly Func<ActivityExecutionContext, ValueTask<T>> _activity;
+
+    public Inline(Func<ActivityExecutionContext, ValueTask<T>> activity, RegisterLocationReference? output = default)
+    {
+        _activity = activity;
+        if (output != null) Result = new Output(output);
+    }
+
+    public Inline(Func<ValueTask<T>> activity, RegisterLocationReference? output = default) : this(_ => activity(), output)
+    {
+    }
+
+    public Inline(Func<ActivityExecutionContext, T> activity, RegisterLocationReference? output = default) : this(c =>
+    {
+        var result = activity(c);
+        return new ValueTask<T>(result);
+    }, output)
+    {
+    }
+
+    public Inline(Func<T> activity, RegisterLocationReference? output = default) : this(c =>
+    {
+        var result = activity();
+        return new ValueTask<T>(result);
+    }, output)
+    {
+    }
+
+    protected override async ValueTask ExecuteAsync(ActivityExecutionContext context)
+    {
+        var result = await _activity(context);
+        context.Set(Result, result);
+    }
+}

src/core/Elsa.Core/Activities/Workflows/Composite.cs

@@ -0,0 +1,62 @@
+using Elsa.Activities.Primitives;
+using Elsa.Attributes;
+using Elsa.Contracts;
+using Elsa.Models;
+
+namespace Elsa.Activities.Workflows;
+
+/// <summary>
+/// Represents a composite activity that has a single <see cref="Root"/> activity.
+/// </summary>
+public class Composite : Activity
+{
+    /// <summary>
+    /// The activity to schedule when this activity executes.
+    /// </summary>
+    [Outbound]
+    public IActivity Root { get; protected set; } = new Sequence();
+
+    protected override void Execute(ActivityExecutionContext context)
+    {
+        context.SubmitActivity(Root, OnCompletedAsync);
+    }
+
+    protected virtual ValueTask OnCompletedAsync(ActivityExecutionContext context, ActivityExecutionContext childContext) => ValueTask.CompletedTask;
+
+    protected static Inline From(Func<ActivityExecutionContext, ValueTask> activity) => new(activity);
+    protected static Inline From(Func<ValueTask> activity) => new(activity);
+    protected static Inline From(Action<ActivityExecutionContext> activity) => new(activity);
+    protected static Inline From(Action activity) => new(activity);
+    protected static Inline<TResult> From<TResult>(Func<ActivityExecutionContext, ValueTask<TResult>> activity, RegisterLocationReference? output = default) => new(activity, output);
+    protected static Inline<TResult> From<TResult>(Func<ValueTask<TResult>> activity, RegisterLocationReference? output = default) => new(activity, output);
+    protected static Inline<TResult> From<TResult>(Func<ActivityExecutionContext, TResult> activity, RegisterLocationReference? output = default) => new(activity, output);
+    protected static Inline<TResult> From<TResult>(Func<TResult> activity, RegisterLocationReference? output = default) => new(activity, output);
+}
+
+/// <summary>
+/// Represents a composite activity that has a single <see cref="Root"/> activity and returns a result.
+/// </summary>
+public class Composite<T> : Activity<T>
+{
+    /// <summary>
+    /// The activity to schedule when this activity executes.
+    /// </summary>
+    [Outbound]
+    public IActivity Root { get; protected set; } = new Sequence();
+
+    protected override void Execute(ActivityExecutionContext context)
+    {
+        context.SubmitActivity(Root, OnCompletedAsync);
+    }
+
+    protected virtual ValueTask OnCompletedAsync(ActivityExecutionContext context, ActivityExecutionContext childContext) => ValueTask.CompletedTask;
+
+    protected static Inline From(Func<ActivityExecutionContext, ValueTask> activity) => new(activity);
+    protected static Inline From(Func<ValueTask> activity) => new(activity);
+    protected static Inline From(Action<ActivityExecutionContext> activity) => new(activity);
+    protected static Inline From(Action activity) => new(activity);
+    protected static Inline<TResult> From<TResult>(Func<ActivityExecutionContext, ValueTask<TResult>> activity, RegisterLocationReference? output = default) => new(activity, output);
+    protected static Inline<TResult> From<TResult>(Func<ValueTask<TResult>> activity, RegisterLocationReference? output = default) => new(activity, output);
+    protected static Inline<TResult> From<TResult>(Func<ActivityExecutionContext, TResult> activity, RegisterLocationReference? output = default) => new(activity, output);
+    protected static Inline<TResult> From<TResult>(Func<TResult> activity, RegisterLocationReference? output = default) => new(activity, output);
+}

src/core/Elsa.Core/Activities/Workflows/Container.cs

@@ -12,6 +12,13 @@ public abstract class Container : Activity, IContainer
     }
 
     protected Container(params IActivity[] activities) => Activities = activities;
+    
+    protected Container(ICollection<Variable> variables, params IActivity[] activities)
+    {
+        Variables = variables;
+        Activities = activities;
+    }
+
     [Outbound] public ICollection<IActivity> Activities { get; set; } = new List<IActivity>();
     public ICollection<Variable> Variables { get; set; } = new Collection<Variable>();
 

src/core/Elsa.Core/Activities/Workflows/Flowchart.cs

@@ -16,7 +16,7 @@ public class Flowchart : Container
         if (Start == null!)
             return;
 
-        context.ScheduleActivity(Start, OnChildCompleted);
+        context.SubmitActivity(Start, OnChildCompleted);
     }
 
     private ValueTask OnChildCompleted(ActivityExecutionContext context, ActivityExecutionContext childContext)

src/core/Elsa.Core/Activities/Workflows/Sequence.cs

@@ -16,6 +16,10 @@ public class Sequence : Container
     public Sequence(params IActivity[] activities) : base(activities)
     {
     }
+    
+    public Sequence(ICollection<Variable> variables, params IActivity[] activities) : base(variables, activities)
+    {
+    }
 
     protected override void ScheduleChildren(ActivityExecutionContext context)
     {
@@ -31,7 +35,7 @@ public class Sequence : Container
             return;
             
         var nextActivity = childActivities.ElementAt(currentIndex);
-        context.ScheduleActivity(nextActivity, OnChildCompleted);
+        context.SubmitActivity(nextActivity, OnChildCompleted);
         context.UpdateProperty<int>(CurrentIndexProperty, x => x + 1);
     }
 

src/core/Elsa.Core/Extensions/ActivityExecutionContextExtensions.cs

@@ -21,4 +21,7 @@ public static class ActivityExecutionContextExtensions
         workflowExecutionContext.ExecutionLog.Add(logEntry);
         return logEntry;
     }
+
+    public static Variable SetVariable(this ActivityExecutionContext context, string name, object? value) => context.WorkflowExecutionContext.SetVariable(name, value);
+    public static T? GetVariable<T>(this ActivityExecutionContext context, string name) => context.WorkflowExecutionContext.GetVariable<T?>(name);
 }

src/core/Elsa.Core/Models/ActivityExecutionContext.cs

@@ -68,7 +68,7 @@ public class ActivityExecutionContext
     /// </summary>
     public IDictionary<string, object?> JournalData { get; private set; } = new Dictionary<string, object?>();
 
-    public void ScheduleActivity(IActivity? activity, ActivityCompletionCallback? completionCallback = default, IEnumerable<RegisterLocationReference>? locationReferences = default, object? tag = default)
+    public void SubmitActivity(IActivity? activity, ActivityCompletionCallback? completionCallback = default, IEnumerable<RegisterLocationReference>? locationReferences = default, object? tag = default)
     {
         if (activity == null)
             return;
@@ -76,7 +76,7 @@ public class ActivityExecutionContext
         WorkflowExecutionContext.Schedule(activity, this, completionCallback, locationReferences, tag);
     }
 
-    public void ScheduleActivity(IActivity? activity, ActivityExecutionContext owner, ActivityCompletionCallback? completionCallback = default, IEnumerable<RegisterLocationReference>? locationReferences = default, object? tag = default)
+    public void SubmitActivity(IActivity? activity, ActivityExecutionContext owner, ActivityCompletionCallback? completionCallback = default, IEnumerable<RegisterLocationReference>? locationReferences = default, object? tag = default)
     {
         if (activity == null)
             return;
@@ -89,7 +89,7 @@ public class ActivityExecutionContext
     public void ScheduleActivities(IEnumerable<IActivity?> activities, ActivityCompletionCallback? completionCallback = default)
     {
         foreach (var activity in activities)
-            ScheduleActivity(activity, completionCallback);
+            SubmitActivity(activity, completionCallback);
     }
 
     public void CreateBookmarks(IEnumerable<object> bookmarkData, ExecuteActivityDelegate? callback = default)

src/core/Elsa.Core/Models/Composite.cs

@@ -1,17 +0,0 @@
-using Elsa.Activities.Workflows;
-using Elsa.Attributes;
-using Elsa.Contracts;
-
-namespace Elsa.Models;
-
-public abstract class Composite : Activity
-{
-    [Outbound] public IActivity Root { get; protected set; } = new Sequence();
-
-    protected override void Execute(ActivityExecutionContext context)
-    {
-        context.ScheduleActivity(Root, OnCompletedAsync);
-    }
-
-    protected virtual ValueTask OnCompletedAsync(ActivityExecutionContext context, ActivityExecutionContext childContext) => ValueTask.CompletedTask;
-}

src/modules/Elsa.Modules.Scheduling/Activities/Delay.cs

@@ -5,8 +5,17 @@ using Elsa.Models;
 
 namespace Elsa.Modules.Scheduling.Activities;
 
+[Activity("Scheduling", "Delays execution for the specified amount of time.")]
 public class Delay : Activity
 {
+    public Delay()
+    {
+    }
+
+    public Delay(Input<TimeSpan> timeSpan) => TimeSpan = timeSpan;
+    public Delay(TimeSpan timeSpan) => TimeSpan = new Input<TimeSpan>(timeSpan);
+    public Delay(Variable<TimeSpan> timeSpan) => TimeSpan = new Input<TimeSpan>(timeSpan);
+
     [Input] public Input<TimeSpan> TimeSpan { get; set; } = default!;
 
     protected override void Execute(ActivityExecutionContext context)

src/samples/console/Elsa.Samples.Console1/Workflows/VariablesWorkflow.cs

@@ -20,7 +20,7 @@ public static class VariablesWorkflow
                 new WriteLine(context => greeting.Get(context)),
                 new ReadLine
                 {
-                    Output = new Output<string?>(name)
+                    Result = new Output<string?>(name)
                 },
                 new WriteLine(new DelegateReference(context => $"Nice to meet you, {name.Get(context)}!")),
             }

src/samples/console/Elsa.Samples.Console2/Program.cs

@@ -32,7 +32,7 @@ typeSystem.Register<HttpEndpoint>();
 typeSystem.Register<Timer>();
 
 functionActivityRegistry.RegisterFunction("print", nameof(WriteLine), new[] { nameof(WriteLine.Text) });
-functionActivityRegistry.RegisterFunction("read", nameof(ReadLine), new[] { nameof(ReadLine.Output) });
+functionActivityRegistry.RegisterFunction("read", nameof(ReadLine), new[] { nameof(ReadLine.Result) });
 
 var assembly = Assembly.GetExecutingAssembly();
 var resource = assembly.GetManifestResourceStream("Elsa.Samples.Console2.Sample1.elsa");