As I mentioned in my last post, I’ve been working on a sample where I host OpenSpan adapters inside of a WPF Prism application. Here’s a screenshot that will help give you a sense of it.

When I started fleshing out the sample, I realized that WPF didn’t provide an object that implemented ISynchronizeInvoke that I could pass to the adapter Start method. As a little background, we added an overload to the Start method that takes an instance of ISynchronizeInvoke as a convenience for developers using adapters within windows forms applications. Normally, within the OpenSpan runtime, adapters fire asynchronous events on thread pool threads. Our automation surface abstracts the invocations required to interact with windows forms from visual developers.

When hosting adapters directly in .NET, we quickly realized that it was painful to force developers to invoke onto the windows forms thread anytime they needed to update their UI within an adapter event. Thus, we added an overload to the Start method where developers could pass in an instance of ISynchronizeInvoke. In practice, since all windows forms controls implement ISynchronizeInvoke, developers simply pass in their form or user control. When an adapter is started with an instance of ISynchronizeInvoke, it will automatically invoke all events onto the right thread.

However, the WPF Dispatcher object, which provides equivalent functionality to ISynchronizeInvoke, does not actually implement ISynchronizeInvoke. A quick search revealed that other folks had run into the same issue with WPF and created wrappers. However, looking over the wrappers, they weren’t entirely complete. It seems that nobody had implemented every method or property required. In particular I knew that our adapters depended on the EndInvoke method and the IAsyncResult.AsyncWaitHandle property.

To remedy this, I implemented my own wrapper. In addition to the public DispatchWrapper, I created a couple of nested private classes, DispatchOperationWrapper and DispatcherOperationWaitHandle, to hide the IAsyncResult and WaitHandle implementation details. Unlike some of the samples I found the implementation below doesn’t use any looping or sleeps to wait. Also note that the implementation for IAsyncResult.CompletedSynchronously always return false. This conforms to the IAsyncResult guidance on MSDN.

using System;using System.Threading;using System.Windows.Threading;

namespace OpenSpan.Samples{ public class DispatcherWrapper : ISynchronizeInvoke {  private Dispatcher _Dispatcher;

  public DispatcherWrapper(Dispatcher dispatcher)  {   _Dispatcher = dispatcher;  }

  #region ISynchronizeInvoke Members  public IAsyncResult BeginInvoke(Delegate method, object[] args)  {   DispatcherOperation op = _Dispatcher.BeginInvoke(method, args);   return new DispatcherOperationWrapper(op);  }

  public object EndInvoke(IAsyncResult result)  {   DispatcherOperationWrapper wrapper = result as DispatcherOperationWrapper;   if (wrapper != null)   {    wrapper.Operation.Wait();    return wrapper.Operation.Result;   }   throw new ArgumentException("Result does not wrap a DispatchOperation");  }

  public object Invoke(Delegate method, object[] args)  {   return _Dispatcher.Invoke(method, args);  }

  public bool InvokeRequired  {   get { return _Dispatcher.CheckAccess(); }  }

  #endregion

  private class DispatcherOperationWrapper : IAsyncResult  {   private DispatcherOperationWaitHandle _WaitHandle;   private DispatcherOperation _Operation;   private object _State;

   public DispatcherOperationWrapper(DispatcherOperation operation)   {    _Operation = operation;   }

   public DispatcherOperationWrapper(DispatcherOperation operation, object state)    : this(operation)   {    _State = state;   }

   public DispatcherOperation Operation   {    get    {     return _Operation;    }   }

   #region IAsyncResult Members   public object AsyncState   {    get { return _State; }   }

   public WaitHandle AsyncWaitHandle   {    get    {     if (_WaitHandle == null)     {      _WaitHandle = new DispatcherOperationWaitHandle(_Operation);     }     return _WaitHandle;    }   }

   public bool CompletedSynchronously   {    get { return false; }   }

   public bool IsCompleted   {    get { return (_Operation.Status == DispatcherOperationStatus.Completed); }   }   #endregion

   private class DispatcherOperationWaitHandle : WaitHandle   {    private DispatcherOperation _Operation;

    public DispatcherOperationWaitHandle(DispatcherOperation operation)    {     _Operation = operation;    }

    public override bool WaitOne()    {     DispatcherOperationStatus status = _Operation.Wait();     return (status == DispatcherOperationStatus.Completed);    }

    public override bool WaitOne(int milliseconds)    {     return this.WaitOne(new TimeSpan(0, 0, 0, 0, milliseconds));    }

    public override bool WaitOne(int milliseconds, bool exitContext)    {     return WaitOne(milliseconds);    }

    public override bool WaitOne(TimeSpan timeout)    {     DispatcherOperationStatus status = _Operation.Wait(timeout);     return (status == DispatcherOperationStatus.Completed);    }

    public override bool WaitOne(TimeSpan timeout, bool exitContext)    {     return this.WaitOne(timeout);    }   }  } }}

This past week I’ve been working on a sample illustrating how to host OpenSpan within WPF. Specifically, I’ve been working on using our re-parenting control to host external applications within the Prism application block from Microsoft.

For my first attempt at using the re-parenting control, I created a WPF user control with this XAML:

<UserControl x:Class="StockTraderRI.Modules.Research.GoogleFinanceView"    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"    xmlns:os="clr-namespace:OpenSpan.Controls.Reparenting.TabbedReparentContainer;assembly=OpenSpan.Controls"    Height="Auto" Width="Auto">    <DockPanel LastChildFill="True">        <TextBlock Text="{Binding TickerSymbol}" Style="{StaticResource CurrentSymbolTitle}" DockPanel.Dock="Top" />        <WindowsFormsHost Name="_WindowsFormsHost">            <os:TabbedReparentContainer Load="OnReparentContainerLoad" Disposed="OnReparentContainerDisposed" />        </WindowsFormsHost>    </DockPanel></UserControl>

As you can see I declaratively added the TabbedReparentContainer within the WindowsFormHost. In the load event handler I created and started the adapter:

private void OnReparentContainerLoad(object sender, EventArgs e){ _Google = new GoogleFinanceAdapter(); _Google.HomePage.Created += OnGoogleHomePageCreated; _Google.Start();}

The setup was very easy so I was feeling pretty confident until I ran the project and received this exception: “Unable to start message form.”

I was puzzled since I knew that the exception occurs when we cannot start the windows form we use internally for inter-process communication. What could be stopping us from starting the windows form? To find out, I downloaded the latest version of Reflector and started debugging. If you haven’t used it, the latest version of Reflector let’s you debug decompiled .NET assemblies within Visual Studio. With Reflector it was pretty easy to see that we were stuck in System.Windows.Forms.NativeWindow:

public virtual void CreateHandle(CreateParams cp){ System.Windows.Forms.IntSecurity.CreateAnyWindow.Demand(); if (((cp.Style & 0x40000000) != 0x40000000) || (cp.Parent == IntPtr.Zero)) {  System.Windows.Forms.IntSecurity.TopLevelWindow.Demand(); } lock (this) {  this.CheckReleased();  WindowClass class2 = WindowClass.Create(cp.ClassName, cp.ClassStyle);  lock (createWindowSyncObject) // <== STUCK  {   // ...  } }}

So there you have it. When .NET is creating a window on one thread, you cannot start another thread and create a window on it at the same time. I’m not really sure why this restriction exists as there isn’t anything inside of the lock that looks particularly unsafe. Nevertheless, because of this, you cannot start adapters synchronously within the Load event, at least in Beta 2.

I’m continuing to work on this sample and will keep posting other interesting things I find over the next few days.

Francis had an interesting post earlier this week: Not using OpenSpan? You could be losing millions. His basic premise is that if you’re not using OpenSpan, you’re losing millions of dollars. The funny thing is that he’s right. This isn’t just hyperbole. Our customers really do save millions of dollars. So why isn’t the world beating a path to our door? Simply put, it’s because the technology community thinks we are the “wrong” way of solving problems.

Are your users having to cut and paste and toggle between too many applications? An OpenSpan developer can develop a solution to that problem in minutes and deploy it in days. But the “right” way of solving that problem is to integrate the applications on the back-end and provide a new user interface. How long is that going to take? I bet it’s longer than a few days.

Are your users having to navigate between too many screens to complete a task? An OpenSpan developer can develop a solution to that problem in minute and deploy it in days. But the “right” way of solving that problem is to rewrite the application and provide a better user interface. How long is that going to take? I bet it’s longer than a few days.

I could keep going, but I think you get the picture. Of course, the real question is what is “right”? If “right” is defined as the most elegant solution that will be most extensible in the future, then OpenSpan is the wrong solution. If “right” is defined as the most cost-effective and rapid solution that will provide value to the business, then OpenSpan is the “right” solution.

Ultimately, the “right” answer it to do both. Solve the business problems in the short term with OpenSpan and in the long term with your strategic architecture. Most IT organizations have backlogs that contain thousands of feature requests. Usability issues, unless they are absolutely horrendous, almost always get pushed below strategic features. And with the resources available and the time alloted, that’s the right decision. Many of those big features will save hundreds of millions of dollars. While those pesky little features are only worth tens of millions of dollars.

But why waste those tens of millions of dollars when you could implement them quickly and cheaply with OpenSpan? Just today, we had a deal killed by a CTO who said, “Don’t worry about that, we’re reimplementing that application anyway. It’s a waste of money.” Really? It’s a waste of money to buy a product where the ROI is typically delivered in less than three months? Whose cost of ownership is a tenth of the savings it delivers? That enables a team of less than five developers to save a company millions?

I try not to criticize the organizations we sell to, but it’s incredible the narrow attitudes that prevail in our industry. Real agile practitioners know that you get the best results by delivering value rapidly. Every day, I tell my team to ask themselves “What’s the value of what I’m doing? Is there anyway I can deliver the same value better or faster?” Although agile is on the rise, it seems clear that the core principles behind agile have yet to filter up to the decision makers within organizations.

Here’s the bottom line: If you’re not using OpenSpan, you’re not delivering the value you should deliver. You’re wasting money and you’re hurting your business.

I couldn’t believe the response we have been seeing to the new download program. The fact that you can now be your own superstar and save your company $100,000′s or $Millions of dollars. Just by downloading our product, building some slick and quick automations in a few hours and see how much you can save – all without leaving your chair or spending a dime up front.  Some real use cases;

Back office Automation – Finance. Process 500% more transactions a day with the same people by automating the end users manual navigations between mainframe, spreadsheets and web (Java) applications. The savings quite literally are over $15m a year. 10 weeks to build/QA/Pilot and go live!

Back Office Automation – Finance. Processing times cut by over 90% for opening new accounts whilst assuring compliancy with ever changing rules. Implemented in weeks.

Call Center Automation – Finance. Call times cut by 28% for managing customer account queries spread over multiple systems. Automated Process Guidance implemented to ensure ease of workflows.

Call Center Automation – Telecoms. Automated almost entire Caller verification process spread over multiple systems. Saved over $30m on first project in first year alone through reduced AHT.

Call Center Automation – Insurance. Reduced time to update multiple systems from 35 minutes to under 10 minutes.

We have hundreds of automation examples like this, hundreds. We have customers who use us where they have just 1 desktop user using it (even zero users in unattended mode) and we have organizations where we are installed, in production on over 20,000 user desktops.

The point is, by downloading the OpenSpan product you don’t’ have to wait months before you see the benefits. OpenSpan is a true product. Download it, build something big or small and if it’s going to save you money, and lots of it, as it likely will, move it into production. Then, keep building and keep saving.

That’s what I mean about being a true product. We can save you a ton of money, and start saving it for you, right now. It costs nothing to try. www.openspan.com/community

You don’t even need to be a hard core developer, just have some basic “programatic” thinking skills and you’ll be automating in minutes with the OpenSpan Studio product! But if you are a hardcore developer, that’s OK too, you can run OpenSpan Plug-in for Visual Studio and write code, or mix and match between the visual workflow designer and your favorite programming language! You can choose.