public static async Task <ScheduleViewItemsGroup> LoadAsync(Guid localAccountId, Guid semesterId, bool trackChanges = true, bool includeWeightCategories = true)
{
ScheduleViewItemsGroup answer;
bool usedCached = false;
// Find a cached match
// Note that if the requester doesn't require weight categories, we'll ignore checking that includeWeightCategories matches,
// since returning a cache that includes weight categories doesn't harm anything.
lock (_cachedItems)
{
var cached = _cachedItems.FirstOrDefault(i =>
i.LocalAccountId == localAccountId &&
i.SemesterId == semesterId &&
(!includeWeightCategories || i._includeWeightCategories == includeWeightCategories));
// If we'd like the changes tracked and we already have a matching cached
if (trackChanges && cached != null)
{
usedCached = true;
answer = cached;
}
else
{
// Otherwise, no cached or no change tracking requested, so load new
answer = new ScheduleViewItemsGroup(localAccountId, semesterId, trackChanges, includeWeightCategories);
answer._loadingTask = Task.Run(answer.LoadBlocking);
// If we're tracking changes, we'll add it to the cached
if (trackChanges)
{
_cachedItems.Add(answer);
}
}
}
try
{
await answer._loadingTask;
return(answer);
}
catch
{
if (usedCached)
{
// If we were using cached and it previously failed to load,
// we remove it and try again
lock (_cachedItems)
{
_cachedItems.Remove(answer);
}
}
else
{
throw;
}
}
// We try to load again since we used cached and it failed previously
return(await LoadAsync(localAccountId, semesterId, trackChanges : trackChanges, includeWeightCategories : includeWeightCategories));
}
protected async Task LoadBlocking(Guid examId)
{
var dataStore = await GetDataStore();
if (dataStore == null)
{
throw new NullReferenceException("Account doesn't exist");
}
DataItemMegaItem dataItem;
// We need ALL classes loaded, including their schedules, and their weight categories.
// Might as well just use ScheduleViewItemsGroup therefore.
Guid semesterId;
Guid classId = Guid.Empty;
using (await Locks.LockDataForReadAsync("BaseSingleItemViewItemsGroup.LoadBlocking"))
{
dataItem = dataStore.TableMegaItems.FirstOrDefault(i => i.Identifier == examId);
if (dataItem == null)
{
TelemetryExtension.Current?.TrackEvent("Error_LoadSingleItem_CouldNotFind", new Dictionary <string, string>()
{
{ "ItemId", examId.ToString() }
});
// Leave the Item set to null
return;
}
if (dataItem.MegaItemType == PowerPlannerSending.MegaItemType.Task || dataItem.MegaItemType == PowerPlannerSending.MegaItemType.Event)
{
semesterId = dataItem.UpperIdentifier;
classId = dataItem.UpperIdentifier;
}
else
{
var dataClass = dataStore.TableClasses.FirstOrDefault(i => i.Identifier == dataItem.UpperIdentifier);
if (dataClass == null)
{
throw new NullReferenceException("Class not found. Item id " + examId);
}
semesterId = dataClass.UpperIdentifier;
classId = dataClass.Identifier;
}
}
_scheduleViewItemsGroup = await ScheduleViewItemsGroup.LoadAsync(LocalAccountId, semesterId : semesterId, trackChanges : trackChanges, includeWeightCategories : true);
// Grab the class for the item
ViewItemClass viewClass;
if (dataItem.MegaItemType == PowerPlannerSending.MegaItemType.Task || dataItem.MegaItemType == PowerPlannerSending.MegaItemType.Event)
{
viewClass = _scheduleViewItemsGroup.Semester.NoClassClass;
}
else
{
viewClass = _scheduleViewItemsGroup.Semester.Classes.FirstOrDefault(i => i.Identifier == classId);
if (viewClass == null)
{
throw new NullReferenceException("ViewItemClass not found. Item id " + examId);
}
}
// And create the item
Item = CreateItem(dataItem, viewClass);
}