private static SemesterItemsViewGroup CreateInstance(Guid localAccountId, ViewItemSemester semester, bool trackChanges = true)
{
var answer = new SemesterItemsViewGroup(localAccountId, semester, trackChanges);
answer.LoadingTask = Task.Run(answer.LoadBlocking);
return(answer);
}
///// <summary>
///// Eliminates any items that have become expired (like events that have expired)
///// </summary>
//private void Refilter()
//{
// // Beware - can't do this from a background thread or else it would crash things
// // Hence we actually need to only do this from a UI thread and also ensure to put it in the
// // lock so that background threads using cached item don't get messed up
// Guid[] classIdentifiers = Classes.Select(i => i.Identifier).ToArray();
// DateTime todayAsUtc = DateTime.SpecifyKind(DateTime.Today, DateTimeKind.Utc);
// this.Items.RemoveWhere(i => !ShouldIncludeItem(i.DataItem as DataItemMegaItem, classIdentifiers, todayAsUtc);
//}
private static async Task <AgendaViewItemsGroup> CreateLoadTask(Guid localAccountId, ViewItemSemester semester, DateTime today)
{
var answer = new AgendaViewItemsGroup(localAccountId, semester, today, trackChanges: true);
SemesterItemsViewGroup cached = SemesterItemsViewGroup.GetCached(semester.Identifier);
if (cached != null)
{
// Can perform this without locks since we already know we're on UI thread right now,
// and any modifications to the SemesterItems list would need to be on UI thread to occur
await cached.LoadingTask;
answer.PrepareFromCached(cached);
}
else
{
await Task.Run(answer.LoadBlocking);
}
return(answer);
}
private void PrepareFromCached(SemesterItemsViewGroup semesterItems)
{
// Hold onto a strong reference of the cached items so they continue updating
_cachedSemesterItems = semesterItems;
this.Items = new AgendaItemsList(Today, semesterItems.Items);
}
public async void LoadHomeworkAndExams()
{
try
{
if (_hasHomeworkAndExamsBeenRequested)
{
return;
}
_hasHomeworkAndExamsBeenRequested = true;
bool hasPastCompletedHomework = false;
bool hasPastCompletedExams = false;
SemesterItemsViewGroup cached = null;
if (this.Class.Semester != null)
{
cached = SemesterItemsViewGroup.GetCached(this.Class.Semester.Identifier);
}
if (cached != null)
{
await cached.LoadingTask;
DataItemMegaItem[] dataMegaItems = cached.Items
.OfType <BaseViewItemHomeworkExam>()
.Select(i => i.DataItem)
.OfType <DataItemMegaItem>()
.ToArray();
this.Class.AddHomeworkAndExamChildrenHelper(CreateHomeworkOrExam, ShouldIncludeHomeworkOrExamFunction(_classId, TodayAsUtc));
this.Class.FilterAndAddChildren(dataMegaItems);
hasPastCompletedHomework = dataMegaItems.Any(IsPastCompletedHomeworkFunction(_classId, TodayAsUtc));
hasPastCompletedExams = dataMegaItems.Any(IsPastCompletedExamFunction(_classId, TodayAsUtc));
}
else
{
await Task.Run(async delegate
{
var dataStore = await GetDataStore();
DataItemMegaItem[] dataHomeworks;
using (await Locks.LockDataForReadAsync())
{
dataHomeworks = dataStore.TableMegaItems.Where(ShouldIncludeHomeworkOrExamFunction(_classId, TodayAsUtc)).ToArray();
this.Class.AddHomeworkAndExamChildrenHelper(CreateHomeworkOrExam, ShouldIncludeHomeworkOrExamFunction(_classId, TodayAsUtc));
this.Class.FilterAndAddChildren(dataHomeworks);
hasPastCompletedHomework = dataStore.TableMegaItems.Any(IsPastCompletedHomeworkFunction(_classId, TodayAsUtc));
hasPastCompletedExams = dataStore.TableMegaItems.Any(IsPastCompletedExamFunction(_classId, TodayAsUtc));
}
});
}
HasPastCompletedHomework = hasPastCompletedHomework;
HasPastCompletedExams = hasPastCompletedExams;
Homework = this.Class.HomeworkAndExams.Sublist(ShouldIncludeInNormalHomeworkFunction(TodayAsUtc)).Cast <ViewItemHomework>();
Exams = new MyObservableList <ViewItemExam>();
(Exams as MyObservableList <ViewItemExam>).InsertSorted(
this.Class.HomeworkAndExams.Sublist(ShouldIncludeInNormalExamsFunction()).Cast <ViewItemExam>());
OnPropertyChanged(nameof(Homework));
OnPropertyChanged(nameof(Exams));
_loadHomeworkAndExamsCompletionSource.SetResult(true);
}
catch (Exception ex)
{
TelemetryExtension.Current?.TrackException(ex);
}
}