/// <summary>
/// Show an activity indicator and refresh the page in the background.
/// </summary>
/// <returns></returns>
public async Task RefreshPageAsync()
{
await this.StackLayoutButtonStack.FadeTo(0, 1);
this.ActivityIndicator.IsVisible = true;
this.ActivityIndicator.IsRunning = true;
this.isSetup = false;
await Task.Run(() => QuizRosterDatabase.UpdateLocalDatabaseAsync());
this.CheckSetup();
this.ActivityIndicator.IsVisible = false;
this.ActivityIndicator.IsRunning = false;
await this.StackLayoutButtonStack.FadeTo(1, 1);
}
/// <summary>
/// Called when the user tries to download a quiz
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private async void SyncDownload_Clicked(object sender, EventArgs e)
{
// this.serverConnected = true;
ImageButton button = sender as ImageButton;
string dbId = button.ClassId;
QuizInfo quizInfo = QuizRosterDatabase.GetQuizInfo(dbId);
// DOES THIS WORK?
while (quizInfo == null && Plugin.Connectivity.CrossConnectivity.Current.IsConnected)
{
await QuizRosterDatabase.UpdateLocalDatabaseAsync();
quizInfo = QuizRosterDatabase.GetQuizInfo(dbId);
}
string authorName = quizInfo.AuthorName;
string quizName = quizInfo.QuizName;
string category = quizInfo.Category;
ActivityIndicator indicatorSyncing = (button.Parent as StackLayout).Children[(int)UISyncStatus.Syncing] as ActivityIndicator;
string quizPath = button.ClassId;
button.IsVisible = false;
indicatorSyncing.IsVisible = true;
indicatorSyncing.IsRunning = true;
if (await Task.Run(() => ServerOperations.GetQuiz(dbId, category)))
{
ImageButton buttonSyncNoChange = (button.Parent as StackLayout).Children[(int)UISyncStatus.NoChange] as ImageButton;
indicatorSyncing.IsVisible = false;
buttonSyncNoChange.IsVisible = true;
(((button.Parent as StackLayout).Parent as StackLayout).Parent as Frame).StyleId = "Local";
}
else // If it failed to download
{
indicatorSyncing.IsVisible = false;
button.IsVisible = true;
await this.DisplayAlert("Quiz Download Failed",
"This quiz could not be downloaded from the server. Please try again.",
"OK");
}
indicatorSyncing.IsRunning = false;
await this.UpdateProfileContentAsync(
this.SelectedCategory);
}
/// <summary>
/// Sets up the quizzes owned by this user as cards
/// </summary>
private async Task SetupQuizzes(string category)
{
await QuizRosterDatabase.UpdateLocalDatabaseAsync();
// A single LINQ statement to get all quizzes by the current
// user that is logged in, and of the specified category,
// taking the top 20 of the current chunk ordered by
// the subscriber count of the quizzes
List <QuizInfo> rosterCopy = QuizRosterDatabase.GetRoster();
List <QuizInfo> quizzes =
rosterCopy.
Where(
quizInfo =>
(quizInfo.AuthorName == CredentialManager.Username
&&
(quizInfo.Category == category || category == "All"))).
OrderBy(quizInfo => quizInfo.SubscriberCount).
Take(20 * this.currentChunk).ToList();
this.AddQuizzes(quizzes, false);
}
/// <summary>
/// Update local data through synchronzing data with server.
/// Runs on a timed background task and repeats a synchronization every two minutes.
/// </summary>
/// <returns></returns>
public static async Task RunServerChecksAsync()
{
await CredentialManager.CheckLoginStatusAsync();
await Task.Run(async() => await QuizRosterDatabase.UpdateLocalDatabaseAsync());
var minutes = TimeSpan.FromMinutes(2);
Device.StartTimer(minutes, () =>
{
Task task = Task.Run(async() =>
{
if (CredentialManager.IsLoggedIn)
{
await CredentialManager.CheckLoginStatusAsync();
}
await QuizRosterDatabase.UpdateLocalDatabaseAsync();
BugReportHandler.SubmitSavedReports();
});
// Return true to continue the timer
return(true);
});
}