Silverlight Advanced View Model Style Video Player

// Copyright (c) 2010
// by OpenLight Group
// http://openlightgroup.net/
//
// Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated 
// documentation files (the "Software"), to deal in the Software without restriction, including without limitation 
// the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and 
// to permit persons to whom the Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all copies or substantial portions 
// of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED 
// TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
//
// CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
// DEALINGS IN THE SOFTWARE.

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.ServiceModel;
using MVVMVideoPlayer_Test.wsVideos;
using System.Linq;

namespace MVVMVideoPlayer_Test
{
    public class SilverlightVideos
    {
        #region GetVideos
        public static IObservable<IEvent<GetVideosCompletedEventArgs>> GetVideos()
        {
            // Uses http://msdn.microsoft.com/en-us/devlabs/ee794896.aspx
            // Also see: http://programmerpayback.com/2010/03/11/use-silverlight-reactive-extensions-rx-to-build-responsive-uis/
            // Also see: http://www.silverlightshow.net/items/Using-Reactive-Extensions-in-Silverlight-part-2-Web-Services.aspx            

            // Set up web service call
            WebServiceSoapClient objWebServiceSoapClient =
                new WebServiceSoapClient();

            // Get the base address of the website that launched the Silverlight Application
            EndpointAddress MyEndpointAddress = new
                EndpointAddress(GetBaseAddress());

            // Set that address
            objWebServiceSoapClient.Endpoint.Address = MyEndpointAddress;

            // Set up a Rx Observable that can be consumed by the ViewModel
            IObservable<IEvent<GetVideosCompletedEventArgs>> observable = 
                Observable.FromEvent<GetVideosCompletedEventArgs>(objWebServiceSoapClient, "GetVideosCompleted");
            objWebServiceSoapClient.GetVideosAsync();

            return observable;
        }
        #endregion

        // Utility

        #region GetBaseAddress
        private static string GetBaseAddress()
        {
            string strXapFile = @"/ClientBin/MVVMVideoPlayer_Test.xap";

            string strBaseWebAddress =
                App.Current.Host.Source.AbsoluteUri.Replace(strXapFile, "");

            return string.Format(@"{0}/{1}", strBaseWebAddress, @"WebService/WebService.asmx");
        }
        #endregion
    }
}