title: WCF service singleton with callback and hosted on IIS?
body: <p>I have a WCF service hosted at IIS7 web application. It's created by a WebServiceHostFactory. The client connects to a service calls the Collect method, and data are stored to DB. All working fine.</p>
  
  <p>Now I would like to refresh page every time the new data are "collected" (i.e. the service method Collect is called). </p>
  
  <p>My question is: What is the best approach ?</p>
  
  <p>I was considering the CallbackContract, but this would require a singleton pattern (service is now PerCall), or is it a wrong assumption ? Is this approach possible ? </p>
  
  <p>My logic is: </p>
  
  <ol>
  <li>ASP.NET page subscribes to WCF service</li>
  <li>the service singleton is created from now on</li>
  <li>when method is called the services calls subscribers (clients)</li>
  <li>there should be therefore only one service instance in order to subscription to work (or is it ?)</li>
  <li>the client page refreshes itself</li>
  </ol>
  
  <p>regards,
  Kate</p>