Add support for providing workflow input via dispatch endpoint

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

@@ -3,6 +3,7 @@ using Elsa.Expressions.Models;
 using Elsa.Extensions;
 using Elsa.JavaScript.Notifications;
 using Elsa.Mediator.Contracts;
+using Elsa.Workflows.Core.Contracts;
 using Elsa.Workflows.Core.Models;
 using Elsa.Workflows.Management.Activities;
 using Elsa.Workflows.Management.Activities.WorkflowDefinitionActivity;
@@ -38,27 +39,41 @@ public class WorkflowDefinitionActivityJavaScriptHandler : INotificationHandler<
         var engine = notification.Engine;
         var context = notification.Context;
 
-        // If we are already evaluating inputs, then we're in a circular evaluation loop. In this case, we should not attempt to evaluate the inputs.
-        if(context.TransientProperties.TryGetValue("EvaluatingInputs", out var evaluatingInputs) && (bool)evaluatingInputs)
-            return;
+        // Always create workflow input accessors.
+        CreateWorkflowInputAccessors(engine, context);
         
+        // If we are already evaluating inputs, then we're in a circular evaluation loop. In this case, we should not attempt to evaluate the inputs.
+        if (context.TransientProperties.TryGetValue("EvaluatingInputs", out var evaluatingInputs) && (bool)evaluatingInputs)
+            return;
+
         // To prevent a circular evaluation loop, set a flag on the context to indicate that we're currently evaluating the inputs.
         context.TransientProperties["EvaluatingInputs"] = true;
-        
+
         // Create input getters.
         await CreateInputAccessorsAsync(engine, context);
     }
 
+    private void CreateWorkflowInputAccessors(Engine engine, ExpressionExecutionContext context)
+    {
+        var input = context.GetWorkflowExecutionContext().Input;
+
+        foreach (var inputEntry in input)
+        {
+            var inputPascalName = inputEntry.Key.Pascalize();
+            var inputValue = inputEntry.Value;
+            engine.SetValue($"get{inputPascalName}", (Func<object?>)(() => inputValue));
+        }
+    }
+
     private async Task CreateInputAccessorsAsync(Engine engine, ExpressionExecutionContext context)
     {
-        var workflowDefinitionActivity = GetFirstWorkflowDefinitionActivity(context);
-
+        var workflowDefinitionActivity = context.GetActivityExecutionContext().GetFirstWorkflowDefinitionActivity();
         if (workflowDefinitionActivity == null)
             return;
 
-        var descriptor = _activityRegistry.Find(workflowDefinitionActivity.Type, workflowDefinitionActivity.Version)!;
-        var inputDefinitions = descriptor.Inputs;
-        
+        var workflowDefinitionActivityDescriptor = _activityRegistry.Find(workflowDefinitionActivity.Type, workflowDefinitionActivity.Version);
+        var inputDefinitions = workflowDefinitionActivityDescriptor?.Inputs ?? Enumerable.Empty<InputDescriptor>();
+
         foreach (var inputDefinition in inputDefinitions)
         {
             var inputPascalName = inputDefinition.Name.Pascalize();
@@ -68,7 +83,4 @@ public class WorkflowDefinitionActivityJavaScriptHandler : INotificationHandler<
             engine.SetValue($"get{inputPascalName}", (Func<object?>)(() => evaluatedExpression));
         }
     }
-
-    private static WorkflowDefinitionActivity? GetFirstWorkflowDefinitionActivity(ExpressionExecutionContext context) =>
-        context.GetActivityExecutionContext().GetFirstWorkflowDefinitionActivity();
 }

src/modules/Elsa.JavaScript/Services/JintJavaScriptEvaluator.cs

@@ -70,6 +70,7 @@ public class JintJavaScriptEvaluator : IJavaScriptEvaluator
         engine.SetValue("setCorrelationId", (Action<string?>)(value => context.GetActivityExecutionContext().WorkflowExecutionContext.CorrelationId = value));
         engine.SetValue("setVariable", (Action<string, object>)((name, value) => context.SetVariable(name, value)));
         engine.SetValue("getVariable", (Func<string, object?>)(name => context.GetVariable(name)));
+        engine.SetValue("getInput", (Func<string, object?>)(name => context.GetWorkflowExecutionContext().Input.GetValue(name)));
 
         // Create variable & input setters and getters for each variable.
         CreateMemoryBlockAccessors(engine, context);

src/modules/Elsa.JavaScript/TypeDefinitions/Providers/CommonFunctionsDefinitionProvider.cs

@@ -42,6 +42,11 @@ internal class CommonFunctionsDefinitionProvider : FunctionDefinitionProvider
             .Parameter("name", "string")
             .ReturnType("any"));
         
+        yield return CreateFunctionDefinition(builder => builder
+            .Name("getInput")
+            .Parameter("name", "string")
+            .ReturnType("any"));
+        
         yield return CreateFunctionDefinition(builder => builder
             .Name("isNullOrWhiteSpace")
             .Parameter("value", "string")

src/modules/Elsa.Workflows.Api/Endpoints/WorkflowDefinitions/Dispatch/Endpoint.cs

@@ -34,11 +34,15 @@ internal class Endpoint : ElsaEndpoint<Request, Response>
             await SendNotFoundAsync(cancellationToken);
             return;
         }
+        
+        var correlationId = request.CorrelationId;
+        var input = (IDictionary<string, object>?)request.Input;
 
-        var result = await _workflowDispatcher.DispatchAsync(new DispatchWorkflowDefinitionRequest(
+        await _workflowDispatcher.DispatchAsync(new DispatchWorkflowDefinitionRequest(
                 request.DefinitionId,
                 VersionOptions.Published,
-                CorrelationId: request.CorrelationId),
+                input,
+                correlationId),
             cancellationToken);
 
         await SendOkAsync(new Response(), cancellationToken);

src/modules/Elsa.Workflows.Api/Endpoints/WorkflowDefinitions/Dispatch/Models.cs

@@ -1,11 +1,17 @@
+using System.Text.Json.Serialization;
+using Elsa.Workflows.Core.Serialization.Converters;
+
 namespace Elsa.Workflows.Api.Endpoints.WorkflowDefinitions.Dispatch;
 
-public class Request
+internal class Request
 {
     public string DefinitionId { get; set; } = default!;
     public string? CorrelationId { get; set; }
+
+    [JsonConverter(typeof(ExpandoObjectConverter))]
+    public object? Input { get; set; }
 }
 
-public class Response
+internal class Response
 {
 }

src/modules/Elsa.Workflows.Management/Activities/WorkflowDefinitionActivity/RefreshActivityRegistryHandler.cs

@@ -2,9 +2,8 @@ using Elsa.Mediator.Contracts;
 using Elsa.Workflows.Management.Contracts;
 using Elsa.Workflows.Management.Entities;
 using Elsa.Workflows.Management.Notifications;
-using Elsa.Workflows.Management.Providers;
 
-namespace Elsa.Workflows.Management.Handlers;
+namespace Elsa.Workflows.Management.Activities.WorkflowDefinitionActivity;
 
 /// <summary>
 /// Refreshes the <see cref="IActivityRegistry"/> for the <see cref="WorkflowDefinitionActivityProvider"/> provider whenever an <see cref="WorkflowDefinition"/> is published, retracted or deleted.

src/modules/Elsa.Workflows.Management/Activities/WorkflowDefinitionActivity/WorkflowDefinitionActivityProvider.cs

@@ -1,12 +1,10 @@
 using Elsa.Common.Models;
 using Elsa.Workflows.Core.Models;
-using Elsa.Workflows.Management.Activities;
-using Elsa.Workflows.Management.Activities.WorkflowDefinitionActivity;
 using Elsa.Workflows.Management.Contracts;
 using Elsa.Workflows.Management.Entities;
 using Humanizer;
 
-namespace Elsa.Workflows.Management.Providers;
+namespace Elsa.Workflows.Management.Activities.WorkflowDefinitionActivity;
 
 /// <summary>
 /// Provides activity descriptors based on <see cref="WorkflowDefinition"/>s stored in the database.