Content Correlation within a Native Activity Difficulties

Question

My Goal.  Encapsulate all messaging logic for all of my hosted Workflows.

That is, hiding Message and Content correlation variables etc. from a Workflow Designer.

To do this, I'm building a custom NativeActivity that schedules a Send/Receive, as well as a CorrelationScope activity.  All further workflow will be contained in the body of the CorrelationScope activity.

Notes

• I'm using SQL Persistance
• I'm using the WorkflowInstanceID as my Content Correlation (I think this is the correct vocabulary)

Issue

Basically, I think the correlation handles are not being set within my CorrelationScope therefore the correlation hash's are not matching. Is there a better way to do this?

Here is the error (Prettty standard error for content correlation gone wrong):

Primary Workflow Xaml :

<WorkflowService mc:Ignorable="sap" ConfigurationName="ServiceConfig" sap:VirtualizedContainerService.HintSize="266,290" Name="CustomTest" mva:VisualBasic.Settings="Assembly references and imported namespaces serialized as XML namespaces" xmlns="http://schemas.microsoft.com/netfx/2009/xaml/servicemodel" xmlns:dh="clr-namespace:DataLayer.HumanTaskModel;assembly=DataLayer" xmlns:h="clr-namespace:HostedWorkflow;assembly=HostedWorkflow" xmlns:h1="clr-namespace:HRWorkflow;assembly=HostedWorkflow" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:mv="clr-namespace:Microsoft.VisualBasic;assembly=System" xmlns:mva="clr-namespace:Microsoft.VisualBasic.Activities;assembly=System.Activities" xmlns:p="http://schemas.microsoft.com/netfx/2009/xaml/activities" xmlns:s="clr-namespace:System;assembly=mscorlib" xmlns:s1="clr-namespace:System;assembly=System" xmlns:s2="clr-namespace:System;assembly=System.Xml" xmlns:s3="clr-namespace:System;assembly=System.Core" xmlns:sa="clr-namespace:System.Activities;assembly=System.Activities" xmlns:sad="clr-namespace:System.Activities.Debugger;assembly=System.Activities" xmlns:sap="http://schemas.microsoft.com/netfx/2009/xaml/activities/presentation" xmlns:scg="clr-namespace:System.Collections.Generic;assembly=System" xmlns:scg1="clr-namespace:System.Collections.Generic;assembly=System.ServiceModel" xmlns:scg2="clr-namespace:System.Collections.Generic;assembly=System.Core" xmlns:scg3="clr-namespace:System.Collections.Generic;assembly=mscorlib" xmlns:sd="clr-namespace:System.Data;assembly=System.Data" xmlns:sde="clr-namespace:System.Data.EntityClient;assembly=System.Data.Entity" xmlns:sdod="clr-namespace:System.Data.Objects.DataClasses;assembly=System.Data.Entity" xmlns:sl="clr-namespace:System.Linq;assembly=System.Core" xmlns:ssa="clr-namespace:System.ServiceModel.Activities;assembly=System.ServiceModel.Activities" xmlns:st="clr-namespace:System.Text;assembly=mscorlib" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
  <p:Sequence DisplayName="Sequential Service" sad:XamlDebuggerXmlReader.FileName="C:\Dev\Source\HRManager\HostedWorkflow\CustomTest.xamlx" sap:VirtualizedContainerService.HintSize="236,260" mva:VisualBasic.Settings="Assembly references and imported namespaces serialized as XML namespaces">
    <sap:WorkflowViewStateService.ViewState>
      <scg3:Dictionary x:TypeArguments="x:String, x:Object">
        <x:Boolean x:Key="IsExpanded">True</x:Boolean>
      </scg3:Dictionary>
    </sap:WorkflowViewStateService.ViewState>
    <h1:HumanTaskStartActivity sap:VirtualizedContainerService.HintSize="214,136">
      <h1:HumanTaskStartActivity.Body>
        <h:TaskReserveActivity sap:VirtualizedContainerService.HintSize="200,22" />
      </h1:HumanTaskStartActivity.Body>
    </h1:HumanTaskStartActivity>
  </p:Sequence>
</WorkflowService>

My Custom Activity:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Activities;
using DataLayer;
using System.ServiceModel.Activities;
using System.ComponentModel;
using System.ServiceModel;
using Microsoft.VisualBasic.Activities;
using System.Linq.Expressions;
using System.Activities.Expressions;
using HostedWorkflow;
using System.Xml;

namespace HRWorkflow
{
     [Designer(typeof(HumanTaskStartActivityDesigner))]
    public sealed class HumanTaskStartActivity : NativeActivity
    {
        private Variable<CorrelationHandle> _SendReceiveCorrelationHandle = new Variable<CorrelationHandle>("_SendReceiveHandle");

        // Content (Instance) Correlation
         private Variable<Guid> _InstanceID = new Variable<Guid>("_InstanceID");
         private Variable<CorrelationHandle> ServiceInstanceCorrelationHandle {get;set;}

        private Receive _Receive;
        private SendReply _SendReply;
        private CreateTaskInstance _CreateHumanTaskInstance = new CreateTaskInstance();
        private CorrelationScope _CorrelationScope;
     
        public Activity Body{ get; set; }

        public HumanTaskStartActivity()     : base()
        {
            this.ServiceInstanceCorrelationHandle = new Variable<CorrelationHandle>("_WorkflowInstanceHandle");
            this._CorrelationScope = new CorrelationScope { CorrelatesWith = ServiceInstanceCorrelationHandle };
            this.Body = this._CorrelationScope.Body;
        }

        protected override void CacheMetadata(NativeActivityMetadata metadata)
        {
            metadata.AddImplementationVariable(ServiceInstanceCorrelationHandle);

            _Receive = _Receive ?? new Receive();
            _SendReply = _SendReply ?? new SendReply();
            _Receive.CanCreateInstance = true;
            _Receive.ServiceContractName = "IHumanTaskService";
            _Receive.OperationName = "Start";
            _SendReply.Request = _Receive;
            _SendReply.PersistBeforeSend = true;

            // Add Implementation Variables
            metadata.AddImplementationChild(_Receive);
            metadata.AddImplementationChild(_SendReply);
            metadata.AddImplementationVariable(_InstanceID);
            metadata.AddImplementationChild(_CorrelationScope);
            metadata.AddChild(this.Body);
            metadata.AddImplementationChild(_CreateHumanTaskInstance);
            metadata.AddImplementationVariable(_SendReceiveCorrelationHandle);


            // Create the RequestReplyInitializer that handles correlation between the Send and Receive activities
            var requestReplyInitializer = new RequestReplyCorrelationInitializer()
            {
                CorrelationHandle = _SendReceiveCorrelationHandle
            };

            // Add the RequestReplyInitializer to the Receive Activiites list of CorrelationInitializers
            _Receive.CorrelationInitializers.Add(requestReplyInitializer);

            var x = new XPathMessageQuery();
            x.Namespaces.AddNamespace("xg0","http://schemas.microsoft.com/2003/10/Serialization/");
            x.Expression = "sm:body()/xg0:guid";

  
            // Create the correlation initializer that correlates this service instance
            var instanceCorrelationInitializer = new QueryCorrelationInitializer
            {

                CorrelationHandle = ServiceInstanceCorrelationHandle,
                  
                MessageQuerySet = new MessageQuerySet
                {
                    { "KeyInstanceIDStart", x} 
                    
                }
            };

            // Add a Parameter that will send back the Workflow InstanceID that will be used as the service's correlation value
             _SendReply.Content = new SendMessageContent { Message = new InArgument<Guid>(_InstanceID) };

            // Add the service instance correlation to the intializers of the SendReply activity
            _SendReply.CorrelationInitializers.Add(instanceCorrelationInitializer);
        }

        protected override void Execute(NativeActivityContext context)
        {
            
            _InstanceID.Set(context, context.WorkflowInstanceId);
            context.ScheduleActivity(_Receive, ReceiveCompleted);

        }

        private void ReceiveCompleted(NativeActivityContext context, ActivityInstance completedInstance)
        {
            context.ScheduleActivity(_SendReply,SendCompleted);
        }

        private void SendCompleted(NativeActivityContext context, ActivityInstance completedInstance)
        {
            context.ScheduleActivity(this._CreateHumanTaskInstance);

            context.ScheduleActivity(this.Body);
        }

    }
}

The child activity with a "Reserve" operation.

<Activity mc:Ignorable="sap" x:Class="HostedWorkflow.TaskReserveActivity" sap:VirtualizedContainerService.HintSize="317,446" mva:VisualBasic.Settings="Assembly references and imported namespaces for internal implementation" xmlns="http://schemas.microsoft.com/netfx/2009/xaml/activities" xmlns:cas="clr-namespace:Custom.Activities.Statements" xmlns:dh="clr-namespace:DataLayer.HumanTaskModel;assembly=DataLayer" xmlns:local="clr-namespace:HostedWorkflow" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:mv="clr-namespace:Microsoft.VisualBasic;assembly=System" xmlns:mva="clr-namespace:Microsoft.VisualBasic.Activities;assembly=System.Activities" xmlns:p="http://tempuri.org/" xmlns:p1="http://schemas.microsoft.com/netfx/2009/xaml/servicemodel" xmlns:s="clr-namespace:System;assembly=mscorlib" xmlns:s1="clr-namespace:System;assembly=System" xmlns:s2="clr-namespace:System;assembly=System.Xml" xmlns:s3="clr-namespace:System;assembly=System.Core" xmlns:s4="clr-namespace:System;assembly=System.ServiceModel" xmlns:sa="clr-namespace:System.Activities;assembly=System.Activities" xmlns:sad="clr-namespace:System.Activities.Debugger;assembly=System.Activities" xmlns:sap="http://schemas.microsoft.com/netfx/2009/xaml/activities/presentation" xmlns:scg="clr-namespace:System.Collections.Generic;assembly=System" xmlns:scg1="clr-namespace:System.Collections.Generic;assembly=System.ServiceModel" xmlns:scg2="clr-namespace:System.Collections.Generic;assembly=System.Core" xmlns:scg3="clr-namespace:System.Collections.Generic;assembly=mscorlib" xmlns:sd="clr-namespace:System.Data;assembly=System.Data" xmlns:sl="clr-namespace:System.Linq;assembly=System.Core" xmlns:ssa="clr-namespace:System.ServiceModel.Activities;assembly=System.ServiceModel.Activities" xmlns:ssx="clr-namespace:System.ServiceModel.XamlIntegration;assembly=System.ServiceModel" xmlns:st="clr-namespace:System.Text;assembly=mscorlib" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
  <Sequence sad:XamlDebuggerXmlReader.FileName="C:\Dev\Source\HRManager\HostedWorkflow\TaskReserveActivity.xaml" sap:VirtualizedContainerService.HintSize="277,406">
    <Sequence.Variables>
      <Variable x:TypeArguments="p1:CorrelationHandle" Name="__handle1" />
    </Sequence.Variables>
    <sap:WorkflowViewStateService.ViewState>
      <scg3:Dictionary x:TypeArguments="x:String, x:Object">
        <x:Boolean x:Key="IsExpanded">True</x:Boolean>
      </scg3:Dictionary>
    </sap:WorkflowViewStateService.ViewState>
    <p1:Receive x:Name="__ReferenceID0" sap:VirtualizedContainerService.HintSize="255,90" OperationName="Reserve" ServiceContractName="p:IHumanTaskService">
      <p1:Receive.CorrelatesOn>
        <p1:XPathMessageQuery x:Key="key1">
          <p1:XPathMessageQuery.Namespaces>
            <ssx:XPathMessageContextMarkup>
              <x:String x:Key="xgSc">http://tempuri.org/</x:String>
            </ssx:XPathMessageContextMarkup>
          </p1:XPathMessageQuery.Namespaces>sm:body()/xgSc:Reserve/xgSc:ID</p1:XPathMessageQuery>
      </p1:Receive.CorrelatesOn>
      <p1:Receive.CorrelationInitializers>
        <p1:RequestReplyCorrelationInitializer CorrelationHandle="[__handle1]" />
      </p1:Receive.CorrelationInitializers>
      <p1:ReceiveParametersContent>
        <OutArgument x:TypeArguments="s:Guid" x:Key="ID" />
      </p1:ReceiveParametersContent>
    </p1:Receive>
    <p1:SendReply Request="{x:Reference __ReferenceID0}" DisplayName="SendReplyToReceive" sap:VirtualizedContainerService.HintSize="255,90" PersistBeforeSend="True">
      <p1:SendParametersContent />
    </p1:SendReply>
    <local:UpdateTaskInstance sap:VirtualizedContainerService.HintSize="255,22" NewState="[DataLayer.HumanTaskModel.HumanTaskStates.Reserved]" />
  </Sequence>
</Activity>

Answer 1

Hi,

A problem here is that parent activity and child activity didn't share the same correlation handler. You may authoring both activities via code, then you can encapsulate the logic without problem.

Answer 2

HI Franconia, I dont explicitly sent the Correlation Handle as the assignment is automatic (or should be) within a CorrelationScope activity.  All child Activities would be contained in the Correlationscope.Body.  The purpose of the CorrelationScope activity is to auto-assign the "CorrelatesWith" InArgument for Receive Activites.

The CorrleationHandle for the Correlation Initializer is set here:

var instanceCorrelationInitializer = new QueryCorrelationInitializer
            {

                CorrelationHandle = ServiceInstanceCorrelationHandle,
...

The CorrelationHandle is then also set for the CorrelationScope here:

  this._CorrelationScope = new CorrelationScope { CorrelatesWith = ServiceInstanceCorrelationHandle };

So from my view, the CorrelationHandle is being shared with the Child Activities through the CorrelationScope activity.

Doesnt work though :(,   seems the CorrelationHandle value is not being propagated.