Netflix Browser for Windows Phone 7 - Part 2

using System;
using System.ComponentModel;
using System.Data.Services.Client;
using System.Diagnostics;

using NetflixCatalog.Model;
using alias=NetflixCatalog.Model;



namespace NetflixBrowser
{
	public class MainViewModel : INotifyPropertyChanged
	{
		readonly alias.NetflixCatalog context;
		DataServiceCollection<Genre> genres;
		DataServiceCollection<Title> newTitles;
		DataServiceCollection<Title> topTitles;
		Title selectedTitle = new Title();

		public MainViewModel()
		{
			// Instantiate the context.
			context = 
				new alias.NetflixCatalog(new Uri("http://odata.netflix.com/Catalog/", UriKind.Absolute));
		}

		public Title SelectedTitle
		{
			get
			{
				return selectedTitle;
			}
			private set
			{
				selectedTitle = value;
				OnPropertyChanged("SelectedTitle");
			}
		}

		public DataServiceCollection<Genre> Genres
		{
			get
			{
				return genres;
			}
			private set
			{
				genres = value;
				OnPropertyChanged("Genres");
			}
		}

		public DataServiceCollection<Title> TopTitles
		{
			get
			{
				return topTitles;
			}
			private set
			{
				topTitles = value;
				OnPropertyChanged("TopTitles");
			}
		}

		public DataServiceCollection<Title> NewTitles
		{
			get
			{
				return newTitles;
			}
			private set
			{
				newTitles = value;
				OnPropertyChanged("NewTitles");
			}
		}

		public bool IsDataLoaded { get; private set; }

		#region INotifyPropertyChanged Members

		public event PropertyChangedEventHandler PropertyChanged;

		#endregion

		protected void OnPropertyChanged(string propertyName)
		{
			if (PropertyChanged != null)
			{
				PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
			}
		}

		public void LoadNewTitles()
		{
			//Instantiate newTitles.
			newTitles = new DataServiceCollection<Title>(context);
			
			/* Using variable in linq expression raises an exception. 
			 * It appears to be an issue with the OData library. 
			 * For this demo the year has been hardcoded.*/
			int currentYear = DateTime.Now.Year;

			//IOrderedQueryable<Title> query =
			//                from t in context.Titles.AddQueryOption("$top", 10).Expand("Genres").Expand("Languages")
			//                where t.Type == "Movie" && t.ReleaseYear == 2010 && t.Dvd.Available
			//                orderby t.Dvd.AvailableFrom descending
							//select t;

			Uri uriQuery = new Uri("/Titles()?$filter=((Type eq 'Movie') and (ReleaseYear eq 2010)) and Dvd/Available&$orderby=Dvd/AvailableFrom desc&$expand=Genres,Languages&$top=10", UriKind.Relative);
			
			// Asynchronously load the result of the query.
			newTitles.LoadAsync(uriQuery);

			newTitles.LoadCompleted += (sender, args) =>
			                           	{
			                           		if (args.Error != null)
			                           		{
			                           			Debug.WriteLine("Requesting NewTitles failed. " + args.Error.Message);
			                           		}
			                           		else
			                           		{
			                           			IsDataLoaded = true;
			                           		}
			                           	};
		}

		public void LoadTopTitles()
		{
			//Instantiate topTitles.
			topTitles = new DataServiceCollection<Title>(context);

			//IOrderedQueryable<Title> query = from t in context.Titles
			//                                    .AddQueryOption("$top", 20).Expand("Genres").Expand("Languages")
			//                                 where t.Type == "Movie" && t.ReleaseYear == 2010 && t.Dvd.Available
			//                                 orderby t.AverageRating descending
			//                                 select t;

			Uri uriQuery = new Uri("/Titles()?$filter=((Type eq 'Movie') and (ReleaseYear eq 2010)) and Dvd/Available&$orderby=AverageRating desc&$expand=Genres,Languages&$top=20", UriKind.Relative);
			
			// Asynchronously load the result of the query.
			topTitles.LoadAsync(uriQuery);

			topTitles.LoadCompleted += (sender, args) =>
			                           	{
			                           		if (args.Error != null)
			                           		{
			                           			Debug.WriteLine("Requesting TopTitles failed. " + args.Error.Message);
			                           		}
			                           		else
			                           		{
			                           			IsDataLoaded = true;
			                           		}
			                           	};
		}

		public void LoadGenres()
		{
			//Instantiate genres.
			genres = new DataServiceCollection<Genre>(context);
			
			//IQueryable<Genre> query = from g in context.Genres
			//                          select g;

			Uri uriQuery = new Uri("/Genres()", UriKind.Relative);
			
			// Asynchronously load the result of the query.
			genres.LoadAsync(uriQuery);

			genres.LoadCompleted += (sender, args) =>
			                        	{
			                        		if (args.Error != null)
			                        		{
			                        			Debug.WriteLine("Requesting titles failed. " + args.Error.Message);
			                        		}
			                        		else
			                        		{
			                        			IsDataLoaded = true;
			                        		}
			                        	};
		}


		public void LoadData()
		{
			LoadTopTitles();
			LoadNewTitles();
			LoadGenres();
		}


	}
}