/// <summary>
/// Reloads notes from server
/// </summary>
private void LoadData()
{
this.IsDataLoaded = false;
this.IsUiEnabled = false;
// preparing a data context
this._context = new NotesDataContext(new Uri(NotesDataServiceUri));
// passing the authentication token obtained from Microsoft Account via the Authorization header
this._context.SendingRequest += (sender, args) =>
{
// let our header look a bit custom
args.RequestHeaders["Authorization"] = Constants.AuthorizationHeaderPrefix + this._authenticationToken;
};
var notes = new DataServiceCollection<Note>(this._context);
notes.LoadCompleted += (sender, args) =>
{
if (this.Notes.Continuation != null)
{
this.Notes.LoadNextPartialSetAsync();
return;
}
if (args.Error == null)
{
this.IsDataLoaded = true;
}
else
{
this.OnError.FireSafely(args.Error);
}
this.IsUiEnabled = true;
};
// Defining a query
var query =
from note in this._context.Notes
orderby note.TimeCreated descending
select note;
// Demonstrating LINQ query dynamic generation.
notes.LoadAsync
(
this._showTodaysNotesOnly
?
// This will be translated into DynamoDb Query on the server, like this:
// DynamoDb index query: SELECT * FROM Note WHERE TimeCreated GreaterThan <some DateTime> AND UserId Equal <some userId> ORDER BY TimeCreated DESC. Index name: TimeCreatedIndex
query.Where(note => note.TimeCreated > DateTime.Today)
:
query
);
this.Notes = notes;
this.NotifyPropertyChanged(() => this.Notes);
}
/// <summary>
/// Stores the user's authentication token internally and reloads notes from server using that token
/// </summary>
public void SetAuthenticationToken(string token)
{
this._authenticationToken = token;
if (string.IsNullOrEmpty(this._authenticationToken))
{
this._context = null;
this.Notes = null;
this.NotifyPropertyChanged(() => this.Notes);
this.IsDataLoaded = false;
this.IsUiEnabled = false;
}
else
{
this.LoadData();
}
}