Silverlight Super Tabs Interface (using View Model / MVVM)

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Windows.Input;

namespace SimpleAttendance
{
    public class MainPageModel : INotifyPropertyChanged
    {
        public MainPageModel()
        {
            // Set the command properties
            LoadDatabaseCommand = new DelegateCommand(LoadDatabase, CanLoadDatabase);
            OpenDayCommand = new DelegateCommand(OpenDay, CanOpenDay);
        }

        // Commands

        #region LoadDatabaseCommand
        public ICommand LoadDatabaseCommand { get; set; }
        public void LoadDatabase(object param)
        {
            if ((!IsDataLoaded) && !(DesignerProperties.IsInDesignTool))
            {
                LoadData();
            }
        }

        private bool CanLoadDatabase(object param)
        {
            if (param != null)
            {
                return !(bool)param;
            }
            else
            {
                return false;
            }
        }
        #endregion

        #region OpenDayCommand
        public ICommand OpenDayCommand { get; set; }
        public void OpenDay(object param)
        {
            try
            {
                // Set the AttendanceDate
                // This will raise the PropertyChanged Behavior  
                // that will trigger the AddAttendanceToTabControl Behavior
                // to add the AttendanceDay.xaml to the Tab control
                AttendanceDate = Convert.ToDateTime(param);
                this.NotifyPropertyChanged("AttendanceDate");
            }
            catch 
            {
                // Bad date entered
            }
        }

        private bool CanOpenDay(object param)
        {
            // Cheing for DesignerProperties.IsInDesignTool
            // prevents us from seeing an error in Expression Blend
            return (param != null && (!(DesignerProperties.IsInDesignTool)));
        }
        #endregion

        // Operations

        #region LoadData
        public void LoadData()
        {
            bool hasKeys = false;
            foreach (var item in SterlingService.Current.Database.Query<Student, int>())
            {
                hasKeys = true;
                break;
            }

            if (!hasKeys)
            {
                SetupData();
            }
        }
        #endregion

        #region SetupData
        private void SetupData()
        {
            // Students
            var StudentData = new List<Student>()
            {
                new Student() { StudentId = 1 , Name = "Student One" },
                new Student() { StudentId = 2 , Name = "Student Two" },
                new Student() { StudentId = 3 , Name = "Student Three" },
                new Student() { StudentId = 4 , Name = "Student Four" },
                new Student() { StudentId = 5 , Name = "Student Five" },
                new Student() { StudentId = 6 , Name = "Student Six" },
                new Student() { StudentId = 7 , Name = "Student Seven" },
                new Student() { StudentId = 8 , Name = "Student Eight" },
                new Student() { StudentId = 9 , Name = "Student Nine" },
                new Student() { StudentId = 10 , Name = "Student Ten" },
            };

            foreach (var item in StudentData)
            {
                SterlingService.Current.Database.Save(item);
            }

            // Enrollments
            var EnrollmentData = new List<Enrollment>()
            {
                new Enrollment() {EnrollmentId = 1, StudentId = 1, StartDate = new DateTime(2010,1,1), StopDate = new DateTime(2010,2,1) },
                new Enrollment() {EnrollmentId = 2, StudentId = 2, StartDate = new DateTime(2010,1,1), StopDate = new DateTime(2010,2,11) },
                new Enrollment() {EnrollmentId = 3, StudentId = 3, StartDate = new DateTime(2010,1,3), StopDate = new DateTime(2010,2,1) },
                new Enrollment() {EnrollmentId = 4, StudentId = 4, StartDate = new DateTime(2010,1,3), StopDate = new DateTime(2010,2,1) },
                new Enrollment() {EnrollmentId = 5, StudentId = 5, StartDate = new DateTime(2010,1,10), StopDate = new DateTime(2010,2,15) },
                new Enrollment() {EnrollmentId = 6, StudentId = 6, StartDate = new DateTime(2010,1,3), StopDate = new DateTime(2010,2,1) },
                new Enrollment() {EnrollmentId = 7, StudentId = 7, StartDate = new DateTime(2010,1,22), StopDate = new DateTime(2010,2,1) },
                new Enrollment() {EnrollmentId = 8, StudentId = 8, StartDate = new DateTime(2010,1,1), StopDate = new DateTime(2010,2,1) },
                new Enrollment() {EnrollmentId = 9, StudentId = 9, StartDate = new DateTime(2010,1,1), StopDate = new DateTime(2010,2,1) },
                new Enrollment() {EnrollmentId = 10, StudentId = 10, StartDate = new DateTime(2010,1,1), StopDate = new DateTime(2010,2,1) }
            };

            foreach (var item in EnrollmentData)
            {
                SterlingService.Current.Database.Save(item);
            }

            // Sample Attendance
            SterlingService.Current.Database.Save(new Attendance()
            {
                AttendanceKey = String.Format("{0}-{1}", "1", new DateTime(2010, 1, 1).Ticks.ToString()),
                EnrollmentId = 1,
                AttendanceDate = new DateTime(2010, 1, 1),
                AttendanceStatus = "P"
            });
        }
        #endregion

        // Properties

        #region IsDataLoaded
        private bool _IsDataLoaded = false;
        public bool IsDataLoaded
        {
            get { return _IsDataLoaded; }
            private set
            {
                if (IsDataLoaded == value)
                {
                    return;
                }
                _IsDataLoaded = value;
                this.NotifyPropertyChanged("IsDataLoaded");
            }
        }
        #endregion

        #region AttendanceDate
        private DateTime? _AttendanceDate = null;
        public DateTime? AttendanceDate
        {
            get { return _AttendanceDate; }
            set
            {
                if (AttendanceDate == value)
                {
                    return;
                }
                _AttendanceDate = value;
                this.NotifyPropertyChanged("AttendanceDate");
            }
        }
        #endregion

        // Utility

        #region INotifyPropertyChanged
        public event PropertyChangedEventHandler PropertyChanged;

        private void NotifyPropertyChanged(String info)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(info));
            }
        }
        #endregion
    }
}