activity workers

Author: danielgerlag

README.md

@@ -166,6 +166,8 @@ These are also available as separate Nuget packages.
 
 * [Events](src/samples/WorkflowCore.Sample04)
 
+* [Activity Workers](src/samples/WorkflowCore.Sample18)
+
 * [Parallel Tasks](src/samples/WorkflowCore.Sample13)
 
 * [Saga Transactions (with compensation)](src/samples/WorkflowCore.Sample17)

WorkflowCore.sln

@@ -137,6 +137,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "WorkflowCore.Tests.Redis",
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "WorkflowCore.DSL", "src\WorkflowCore.DSL\WorkflowCore.DSL.csproj", "{20B98905-08CB-4854-8E2C-A31A078383E9}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "WorkflowCore.Sample18", "src\samples\WorkflowCore.Sample18\WorkflowCore.Sample18.csproj", "{5BE6D628-B9DB-4C76-AAEB-8F3800509A84}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -335,6 +337,10 @@ Global
 		{20B98905-08CB-4854-8E2C-A31A078383E9}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{20B98905-08CB-4854-8E2C-A31A078383E9}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{20B98905-08CB-4854-8E2C-A31A078383E9}.Release|Any CPU.Build.0 = Release|Any CPU
+		{5BE6D628-B9DB-4C76-AAEB-8F3800509A84}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{5BE6D628-B9DB-4C76-AAEB-8F3800509A84}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{5BE6D628-B9DB-4C76-AAEB-8F3800509A84}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{5BE6D628-B9DB-4C76-AAEB-8F3800509A84}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -391,6 +397,7 @@ Global
 		{44644716-0CE8-4837-B189-AB65AE2106AA} = {E6CEAD8D-F565-471E-A0DC-676F54EAEDEB}
 		{78217204-B873-40B9-8875-E3925B2FBCEC} = {E6CEAD8D-F565-471E-A0DC-676F54EAEDEB}
 		{20B98905-08CB-4854-8E2C-A31A078383E9} = {EF47161E-E399-451C-BDE8-E92AAD3BD761}
+		{5BE6D628-B9DB-4C76-AAEB-8F3800509A84} = {5080DB09-CBE8-4C45-9957-C3BB7651755E}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {DC0FA8D3-6449-4FDA-BB46-ECF58FAD23B4}

docs/activities.md

@@ -0,0 +1,50 @@
+# Activities
+
+An activity is defined as an item on an external queue of work, that a workflow can wait for.
+
+In this example the workflow will wait for `activity-1`, before proceeding.  It also passes the value of `data.Value1` to the activity, it then maps the result of the activity to `data.Value2`.
+
+Then we create a worker to process the queue of activity items.  It uses the `GetPendingActivity` method to get an activity and the data that a workflow is waiting for.
+
+
+
+```C#
+public class ActivityWorkflow : IWorkflow<MyData>
+{
+    public void Build(IWorkflowBuilder<MyData> builder)
+    {
+        builder                
+            .StartWith<HelloWorld>()
+            .Activity("activity-1", (data) => data.Value1)
+                .Output(data => data.Value2, step => step.Result)
+            .Then<PrintMessage>()
+                .Input(step => step.Message, data => data.Value2);
+    }
+             
+}
+...
+
+var activity = host.GetPendingActivity("activity-1", "worker1", TimeSpan.FromMinutes(1)).Result;
+
+if (activity != null)
+{
+    Console.WriteLine(activity.Parameters);
+    host.SubmitActivitySuccess(activity.Token, "Some response data");
+}
+
+```
+
+The JSON representation of this step would look like this
+
+```json
+{
+    "Id": "activity-step",
+    "StepType": "WorkflowCore.Primitives.Activity, WorkflowCore",
+    "Inputs": 
+    {
+        "ActivityName": "\"activity-1\"",
+        "Parameters": "data.Value1" 
+    },
+    "Outputs": { "Value2": "step.Result" }
+}
+```

docs/external-events.md

@@ -24,3 +24,4 @@ host.PublishEvent("MyEvent", "0", "hello");
 ## Effective Date
 
 You can also specify an effective date when waiting for events, which allows you to respond to events that may have already occurred in the past, or only ones that occur after the effective date.
+

docs/json-yaml.md

@@ -149,7 +149,7 @@ Steps:
 
 ### WaitFor
 
-The `.WaitFor` can be implemented using 3 inputs as follows
+The `.WaitFor` can be implemented using inputs as follows
 
 | Field                  | Description                 |
 | ---------------------- | --------------------------- |
@@ -184,6 +184,43 @@ Inputs:
 
 ```
 
+### Activity
+
+The `.Activity` can be implemented using inputs as follows
+
+| Field                  | Description                 |
+| ---------------------- | --------------------------- |
+| CancelCondition        | Optional expression to specify a cancel condition  |
+| Inputs.ActivityName    | Expression to specify the activity name            |
+| Inputs.Parameters      | Expression to specify the parameters to pass the activity worker                |
+| Inputs.EffectiveDate   | Optional expression to specify the effective date  |
+
+
+```json
+{
+    "Id": "MyActivityStep",
+    "StepType": "WorkflowCore.Primitives.Activity, WorkflowCore",
+    "NextStepId": "...",
+    "CancelCondition": "...",
+    "Inputs": {
+        "ActivityName": "\"my-activity\"",
+        "Parameters": "data.SomeValue"
+    }
+}
+```
+```yaml
+Id: MyActivityStep
+StepType: WorkflowCore.Primitives.Activity, WorkflowCore
+NextStepId: "..."
+CancelCondition: "..."
+Inputs:
+  ActivityName: '"my-activity"'
+  EventKey: '"Key1"'
+  Parameters: data.SomeValue
+
+```
+
+
 ### If
 
 The `.If` can be implemented as follows

docs/samples.md

@@ -6,6 +6,8 @@
 
 [Events](https://github.com/danielgerlag/workflow-core/tree/master/src/samples/WorkflowCore.Sample04)
 
+[Activity Workers](https://github.com/danielgerlag/workflow-core/tree/master/src/samples/WorkflowCore.Sample18)
+
 [Dependency Injection](https://github.com/danielgerlag/workflow-core/tree/master/src/samples/WorkflowCore.Sample15)
 
 [Parallel ForEach](https://github.com/danielgerlag/workflow-core/tree/master/src/samples/WorkflowCore.Sample09)

mkdocs.yml

@@ -3,6 +3,7 @@ nav:
     - Home: index.md
     - Getting started: getting-started.md
     - External events: external-events.md
+    - Activity workers: activities.md
     - Error handing: error-handling.md
     - Control structures: control-structures.md
     - Saga transactions: sagas.md

src/WorkflowCore/Exceptions/ActivityFailedException.cs

@@ -0,0 +1,12 @@
+using System;
+
+namespace WorkflowCore.Exceptions
+{
+    public class ActivityFailedException : Exception
+    {
+        public ActivityFailedException(object data)
+        {
+            //
+        }
+    }
+}

src/WorkflowCore/Interface/IActivityController.cs

@@ -0,0 +1,25 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace WorkflowCore.Interface
+{
+    public class PendingActivity
+    {
+        public string Token { get; set; }
+        public string ActivityName { get; set; }
+        public object Parameters { get; set; }
+        public DateTime TokenExpiry { get; set; }
+        
+    }
+    
+    public interface IActivityController
+    {
+        Task<PendingActivity> GetPendingActivity(string activityName, string workerId, TimeSpan? timeout = null);
+        Task ReleaseActivityToken(string token);
+        Task SubmitActivitySuccess(string token, object result);
+        Task SubmitActivityFailure(string token, object result);
+
+    }
+}