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Checking the last activity of each Flowswitch / Flowdecision

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What is the best method to iterate through each "path" on a flowchart? (I used this post to start: http://social.msdn.microsoft.com/Forums/en-US/wfprerelease/thread/0218a527-4487-4745-801b-c02eadc20a27/#97ccdead-6833-440d-8401-4c7384cbab91)

For example I have several nodes on the FlowChart, including FlowDecisions and FlowSwitches, and I want to ensure that every path ends on a "ICompletionActivity" (interface implemented by me and attached to a custom activity which completes all the database commits, deletes etc).

So far I have tried the following (passing in the FlowChart itself as a modelItem):

public IList<ValidationErrorInfo> CheckForCompletionActivity(ModelItem modelItem)
        {
            IList<ValidationErrorInfo> validationErrors = new List<ValidationErrorInfo>();

            if (modelItem.View != null)
            {
                ModelItemCollection flowChartNodes = modelItem.Properties["Nodes"].Collection;

                ModelItem lastNode = flowChartNodes.Last();

                if (!CheckLastActivityIsCompletionType(lastNode))
                {
                    ValidationErrorInfo error = new ValidationErrorInfo("No completion activity found on " + modelItem.ToString() + " activity.");

                    validationErrors.Add(error);
                }
            }
            ShowValidationErrors(validationErrors);

            return validationErrors;
        }
        
        private bool CheckLastActivityIsCompletionType(ModelItem modelItem)
        {
            if (modelItem != null)
            {
              return modelItem.ItemType == typeof(ICompletionActivity);
            }

            return false;
        }

I starting by using flowChartNodes.Last() to get the last activity, but I assume that will give me the last activity added to the designer canvas?

Monday, February 22, 2010 7:48 PM

Answers

Well I totally overlooked the obvious....

As I am using flownodes, they have a "Next" property... if it is null, then it should be the last activity and then I can check if it is an ICompletionActivity... job done. Code here:

public IList<ValidationErrorInfo> CheckForCompletionActivity(ModelItem modelItem)
        {
            IList<ValidationErrorInfo> validationErrors = new List<ValidationErrorInfo>();

            if (modelItem.View != null)
            {
                ModelItemCollection flowChartNodes = modelItem.Properties["Nodes"].Collection;

                foreach (ModelItem flowChartNode in flowChartNodes)
                {
                    if (flowChartNode.ItemType == typeof(FlowStep))
                    {
                       
                        if (flowChartNode.Properties["Next"].Value == null)
                        {
                            if (!CheckLastActivityIsCompletionActivity(flowChartNode))
                            {
                                ValidationErrorInfo error = new ValidationErrorInfo("No complete workflow activity found after " + flowChartNode.Properties["Action"].ComputedValue.ToString() + " activity.");

                                validationErrors.Add(error);
                            }
                        }
                    }
                }
             }
            ShowValidationErrors(validationErrors);

            return validationErrors;
        }
        
        private bool CheckLastActivityIsCompletionActivity(ModelItem modelItem)
        {
            if (modelItem != null)
            {
                return modelItem.Properties["Action"].ComputedValue is ICompletionActivity;
            }

            return false;
        }

Marked as answer by Special_Jimmy Monday, February 22, 2010 10:17 PM

Monday, February 22, 2010 10:16 PM

Answered by:

Checking the last activity of each Flowswitch / Flowdecision

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