Sample data source class to use in design-time

MoviesSampleDataSource.cs

using System;
using System.Linq;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Runtime.CompilerServices;
using Windows.ApplicationModel.Resources.Core;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Media.Imaging;
using System.Collections.Specialized;
using System.Threading.Tasks;
using Windows.ApplicationModel;
using Windows.Storage;
using Windows.Data.Json;

// The data model defined by this file serves as a representative example of a strongly-typed
// model that supports notification when members are added, removed, or modified.  The property
// names chosen coincide with data bindings in the standard item templates.
//
// Applications may use this model as a starting point and build on it, or discard it entirely and
// replace it with something appropriate to their needs.

namespace KRATIBMoviesSample.Data
{
    /// <summary>
    /// Creates a collection of groups and items with hard-coded content.
    /// 
    /// SampleDataSource initializes with placeholder data rather than live production
    /// data so that sample data is provided at both design-time and run-time.
    /// </summary>
    public sealed class MoviesSampleDataSource
    {
        private static MoviesSampleDataSource _sampleDataSource = new MoviesSampleDataSource();

        private ObservableCollection<MovieDataYear> _allGroups = new ObservableCollection<MovieDataYear>();
        public ObservableCollection<MovieDataYear> AllGroups
        {
            get { return this._allGroups; }
        }

        public static IEnumerable<MovieDataYear> GetGroups(string uniqueId)
        {
            if (!uniqueId.Equals("AllGroups")) throw new ArgumentException("Only 'AllGroups' is supported as a collection of groups");

            return _sampleDataSource.AllGroups;
        }

        public static MovieDataYear GetGroup(string uniqueId)
        {
            // Simple linear search is acceptable for small data sets
            var matches = _sampleDataSource.AllGroups.Where((group) => group.UniqueId.Equals(uniqueId));
            if (matches.Count() == 1) return matches.First();
            return null;
        }

        public static MovieDataItem GetItem(string uniqueId)
        {
            // Simple linear search is acceptable for small data sets
            var matches = _sampleDataSource.AllGroups.SelectMany(group => group.Items).Where((item) => item.UniqueId.Equals(uniqueId));
            if (matches.Count() == 1) return matches.First();
            return null;
        }

        public MoviesSampleDataSource()
        {
            var group1 = new MovieDataYear("Year-2013", "2013", 2013);

            group1.Items.Add(new MovieDataItem("Movie-Iron-Man-3", // uniqueId
                "Iron Man 3", // Name
                "It's about Tony Stark", // Description
                new String[] { "Action", "Drama" }, // Genres
                "PG-13",
                new DateTime(2013, 01, 01), // DatePublished
                group1,
                new TimeSpan(0, 130, 0), // Duration
                "Assets/posters/iron_man_3.jpg")); // PosterImagePath

            group1.Items.Add(new MovieDataItem("Movie-Iron-Man-4",
                "Iron Man 4",
                "It's about Tony Stark",
                new String[] { "Action", "Comedy" },
                "PG-13",
                new DateTime(2013, 02, 01),
                group1,
                new TimeSpan(0, 140, 0),
                "Assets/posters/iron_man_3.jpg"));

            this.AllGroups.Add(group1);

            var group2 = new MovieDataYear("Year-2014", "2014", 2014);

            group2.Items.Add(new MovieDataItem("Movie-Iron-Man-5",
                "Iron Man 5",
                "It's about Tony Stark laughing",
                new String[] { "Action", "Strategy" },
                "PG-13",
                new DateTime(2014, 01, 01),
                group2,
                new TimeSpan(0, 130, 0),
                "Assets/posters/iron_man_3.jpg"));

            group2.Items.Add(new MovieDataItem("Movie-Iron-Man-6",
                "Iron Man 6",
                "It's about Tony Stark laughing",
                new String[] { "Action", "Comedy" },
                "PG-13",
                new DateTime(2014, 02, 01),
                group2,
                new TimeSpan(0, 140, 0),
                "Assets/posters/iron_man_3.jpg"));

            group2.Items.Add(new MovieDataItem("Movie-Iron-Man-7",
                "Iron Man 7",
                "It's about Tony Stark laughing",
                new String[] { "Action", "Comedy" },
                "PG-13",
                new DateTime(2014, 03, 01),
                group2,
                new TimeSpan(0, 140, 0),
                "Assets/posters/iron_man_3.jpg"));

            this.AllGroups.Add(group2);

            var group3 = new MovieDataYear("Year-2015", "2015", 2015);

            group3.Items.Add(new MovieDataItem("Movie-Iron-Man-5",
                "Iron Man 5",
                "It's about Tony Stark laughing",
                new String[] { "Action", "Strategy" },
                "PG-13",
                new DateTime(2015, 01, 01),
                group3,
                new TimeSpan(0, 130, 0),
                "Assets/posters/iron_man_3.jpg"));

            this.AllGroups.Add(group3);
        }
    }
}