Workflow Manager 1.0 and SharePoint 2013 server object model

(This post is for SharePoint On Premise.)

With the release of Workflow Manager 1.0, developers are encouraged to choose "Client side object model" (CSOM or JSON).  The reason is simple: make SharePoint farm more stable, and easy to migrate to SharePoint Online.

But, what's the drawbacks?

1. Not easy to convert existing SharePoint 2010 workflow assemblies to the new version.

2. Client side object model is not as powerful as Server object model.

3. Learning curve for developers.

4. To improve performance & decrease network latency, may need to consider extra caching module.

All right, if, for some reason, we want to utilize the powerful Workflow Manager 1.0 and SharePoint server object model, what should we do?

One obvious options is to build web services which are hosted on SharePoint server. Then Workflow Manager can call them to get the functionalities.

That's awkard. We have to build two parts for a workflow.

Can we use Server object model in workflow CodeActivity directly, under CodeActivityContext?

The answer is YES. And, it's not too hard.

1. Install and configure Workflow Manager 1.0 on a SharePoint Server.

2. Build the activity.

Need to think about the parameters. I prefer to add 4 parameters to each activity. As the name suggested, the last one will pass in the SPListItem URL and ItemID, so we can get SPWeb and SPListItem easily.

I didn't find a way to put log into workflow history from activity, so all information need to be recorded in parameter "ReturnDetailedInfo".

"ReturnCode" tells the workflow instance whether the activity succeed or fail.
"ReturnValue" return the result.

<Parameter Name="ReturnCode"  Type="System.String, mscorlib" Direction="Out" DesignerType="ParameterNames" Description="Workflow variable output" />
<Parameter Name="ReturnValue"  Type="System.String, mscorlib" Direction="Out" DesignerType="ParameterNames" Description="Workflow variable output" />
<Parameter Name="ReturnDetailedInfo"  Type="System.String, mscorlib" Direction="Out" DesignerType="ParameterNames" Description="Workflow variable output" />
<Parameter Name="CurrentItemUrl" Type="System.String, mscorlib" Direction="In" DesignerType="StringBuilder" />

3. Deploy the workflow (activity) assemblies and solution files to the SharePoint farm and the  workflow server.

Don't forget to create/modify "AllowedTypes.xml" in "C:\Program Files\Workflow Manager\1.0\Workflow\WFWebRoot\bin" and "C:\Program Files\Workflow Manager\1.0\Workflow\Artifacts"

Need to reboot windows service "Workflow Manager Backend" during the deployment.

Reference link: https://msdn.microsoft.com/en-us/library/jj193517(v=azure.10).aspx 

4. Make sure workflow service account has "SPDataAccess" rights of SharePoint Configuration database and the relevant content databases

$PrincipleName = "domainname\_WFServices"

Get-SPWebApplication | %{$_.GrantAccessToProcessIdentity($PrincipleName)}

5. Make sure workflow service account is in "WSS_WPG" local windows user group

Reboot the server after adding the service account to "WSS_WPG".

6. Confirm workflow service account has rights on c2WTS

RDP to the workflow server as the service account. The test can be done through c2WTS Tester

7. Restore the site collection to the target SharePoint farm

Restore-SPSite

8. Make sure workflow service account has rights to access target site collection

We can build a X64 windows console program to test it.
RDP to the workflow server as the service account to test it.

9. Clean up Distributed Cache

Reboot all caching servers, or run the script below on all caching servers.
The script below come from here.

Get-SPServiceInstance | Where-Object { $_.TypeName -eq "Distributed Cache" } | Stop-SPServiceInstance -Confirm:$false | Out-Null
While (Get-SPServiceInstance | Where-Object { $_.TypeName -eq "Distributed Cache" -and $_.Status -ne "Disabled" }) {
    Start-Sleep -Seconds 15
}

Get-SPServiceInstance | Where-Object { $_.TypeName -eq "Distributed Cache" } | Start-SPServiceInstance | Out-Null
While (Get-SPServiceInstance | Where-Object { $_.TypeName -eq "Distributed Cache" -and $_.Status -ne "Online" }) {
    Start-Sleep -Seconds 15
}

10. Build and publish the workflows through SharePoint Designer;

11. IISReset on Web Front End servers

Below is the sample code.

        protected override void Execute(CodeActivityContext context)
        {
            string strTmp = string.Empty;

            SPList objSPList = null;
            SPListItem objSPListItem = null;

            try
            {
                this._ArgCurrentItemUrl = this.CurrentItemUrl.Get(context);
                Uri UriCurrentItemUrl = new Uri(_ArgCurrentItemUrl);
                NameValueCollection queryStrings = HttpUtility.ParseQueryString(UriCurrentItemUrl.Query);
                if (queryStrings["ID"] == null)
                {
                    strTmp = string.Format("list '{0}' doesn't exist!", _CurrentListName);
                    WriteErrorToHistoryLog(strTmp);
                    return;
                }
                this._ItemID = int.Parse(queryStrings.Get("ID"));

                for (int i = 0; i < UriCurrentItemUrl.Segments.Length; i++)
                {
                    if (UriCurrentItemUrl.Segments[i].Equals(@"Lists/", StringComparison.InvariantCultureIgnoreCase))
                    {
                        this._CurrentListName = UriCurrentItemUrl.Segments[i + 1];
                        this._CurrentListName = this._CurrentListName.Substring(0, this._CurrentListName.Length - 1);
                        break;
                    }
                }
                using (SPSite objSPSite = new SPSite(this._ArgCurrentItemUrl))
                {
                    using (SPWeb objSPWeb = objSPSite.OpenWeb())
                    {
                        this._CurrentWebUrl = objSPWeb.Url;
                        objSPList = objSPWeb.Lists.TryGetList(this._CurrentListName);
                        if (objSPList == null)
                        {
                            objSPList = objSPWeb.Lists[this._CurrentListName];
                            if (objSPList == null)
                            {
                                strTmp = string.Format("list '{0}' doesn't exist in web '{1}'!", this._CurrentListName, this._CurrentWebUrl);
                                WriteErrorToHistoryLog(strTmp);
                                throw new Exception(strTmp);
                            }
                            this._CurrentListName = objSPList.Title;
                        }
                        objSPListItem = objSPList.GetItemById(_ItemID);
                        if (objSPListItem == null)
                        {
                            strTmp = string.Format("list item '{0}' doesn't exist in list '{1}', in web '{2}'!",
                                this._ItemID, this._CurrentListName, this._CurrentWebUrl);
                            WriteErrorToHistoryLog(strTmp);
                            return;
                        }
                    }
                }

                this._ArgSQLConnectionString = this.SQLConnectionString.Get(context);
                this._ArgColumnMappingXml = this.ColumnMappingXml.Get(context);
                this._ArgSQLSelectCommand = this.SQLSelectCommand.Get(context);

                GetValueFromSQLTable(context);
            }
            catch (Exception ex)
            {
                strTmp = string.Format(@"Execute(), ex.Message={0}", ex.Message);
                WriteErrorToHistoryLog(strTmp);
                strTmp = string.Format(@"Execute(), ex.StackTrace={0}", ex.StackTrace);
                WriteErrorToHistoryLog(strTmp);
            }
            finally
            {
                this.ReturnCode.Set(context, this._ArgReturnCode);
                this.ReturnValue.Set(context, this._ArgReturnValue);
                this.ReturnDetailedInfo.Set(context, this._ArgReturnDetailedInfo);
            }
        }