public async Task <LoadResult> LoadAsync()
{
if (Context.IsCountQuery)
{
return new LoadResult {
totalCount = await ExecCountAsync()
}
}
;
var result = new LoadResult();
if (Context.UseRemoteGrouping && Context.ShouldEmptyGroups)
{
var groupingResult = await ExecRemoteGroupingAsync();
EmptyGroups(groupingResult.Groups, Context.Group.Count);
result.data = Paginate(groupingResult.Groups, Context.Skip, Context.Take);
result.summary = groupingResult.Totals;
result.totalCount = groupingResult.TotalCount;
if (Context.RequireGroupCount)
{
result.groupCount = groupingResult.Groups.Count();
}
}
else
{
var deferPaging = Context.HasGroups || !Context.UseRemoteGrouping && !Context.SummaryIsTotalCountOnly && Context.HasSummary;
Expression loadExpr;
if (!deferPaging && Context.PaginateViaPrimaryKey && Context.Take > 0)
{
if (!Context.HasPrimaryKey)
{
throw new InvalidOperationException(nameof(DataSourceLoadOptionsBase.PaginateViaPrimaryKey)
+ " requires a primary key."
+ " Specify it via the " + nameof(DataSourceLoadOptionsBase.PrimaryKey) + " property.");
}
var loadKeysExpr = Builder.BuildLoadExpr(Source.Expression, true, selectOverride: Context.PrimaryKey);
var keyTuples = await ExecExprAsync <AnonType>(loadKeysExpr);
loadExpr = Builder.BuildLoadExpr(Source.Expression, false, filterOverride: FilterFromKeys(keyTuples));
}
else
{
loadExpr = Builder.BuildLoadExpr(Source.Expression, !deferPaging);
}
if (Context.HasAnySelect)
{
await ContinueWithGroupingAsync(
await ExecWithSelectAsync(loadExpr),
result
);
}
else
{
await ContinueWithGroupingAsync(
await ExecExprAsync <S>(loadExpr),
result
);
}
if (deferPaging)
{
result.data = Paginate(result.data, Context.Skip, Context.Take);
}
if (Context.ShouldEmptyGroups)
{
EmptyGroups(result.data, Context.Group.Count);
}
}
return(result);
}
async Task <IEnumerable <ExpandoObject> > ExecWithSelectAsync(Expression loadExpr)
{
if (Context.UseRemoteSelect)
{
return(SelectHelper.ConvertRemoteResult(await ExecExprAsync <AnonType>(loadExpr), Context.FullSelect));
}
return(SelectHelper.Evaluate(await ExecExprAsync <S>(loadExpr), Context.FullSelect));
}
async Task ContinueWithGroupingAsync <R>(IEnumerable <R> loadResult, LoadResult result)
{
var accessor = new DefaultAccessor <R>();
if (Context.HasGroups)
{
var groups = new GroupHelper <R>(accessor).Group(loadResult, Context.Group);
if (Context.RequireGroupCount)
{
result.groupCount = groups.Count;
}
await ContinueWithAggregationAsync(groups, accessor, result);
}
else
{
await ContinueWithAggregationAsync(loadResult, accessor, result);
}
}
async Task ContinueWithAggregationAsync <R>(IEnumerable data, IAccessor <R> accessor, LoadResult result)
{
if (Context.UseRemoteGrouping && !Context.SummaryIsTotalCountOnly && Context.HasSummary && !Context.HasGroups)
{
var groupingResult = await ExecRemoteGroupingAsync();
result.totalCount = groupingResult.TotalCount;
result.summary = groupingResult.Totals;
}
else
{
var totalCount = -1;
if (Context.RequireTotalCount || Context.SummaryIsTotalCountOnly)
{
totalCount = await ExecCountAsync();
}
if (Context.RequireTotalCount)
{
result.totalCount = totalCount;
}
if (Context.SummaryIsTotalCountOnly)
{
result.summary = Enumerable.Repeat((object)totalCount, Context.TotalSummary.Count).ToArray();
}
else if (Context.HasSummary)
{
data = Buffer <R>(data);
result.summary = new AggregateCalculator <R>(data, accessor, Context.TotalSummary, Context.GroupSummary).Run();
}
}
result.data = data;
}
Task <int> ExecCountAsync()
{
var expr = Builder.BuildCountExpr(Source.Expression);
#if DEBUG
ExpressionWatcher?.Invoke(expr);
#endif
if (AsyncHelper != null)
{
return(AsyncHelper.CountAsync(expr));
}
return(Task.FromResult(Source.Provider.Execute <int>(expr)));
}
async Task <RemoteGroupingResult> ExecRemoteGroupingAsync()
{
return(RemoteGroupTransformer.Run(
typeof(S),
await ExecExprAsync <AnonType>(Builder.BuildLoadGroupsExpr(Source.Expression)),
Context.HasGroups ? Context.Group.Count : 0,
Context.TotalSummary,
Context.GroupSummary
));
}
Task <IEnumerable <R> > ExecExprAsync <R>(Expression expr)
{
#if DEBUG
ExpressionWatcher?.Invoke(expr);
#endif
if (AsyncHelper != null)
{
var result = AsyncHelper.ToEnumerableAsync <R>(expr);
#if DEBUG
if (UseEnumerableOnce)
{
result = result.ContinueWith(t => (IEnumerable <R>) new EnumerableOnce <R>(t.Result));
}
#endif
return(result);
}
else
{
IEnumerable <R> result = Source.Provider.CreateQuery <R>(expr);
#if DEBUG
if (UseEnumerableOnce)
{
result = new EnumerableOnce <R>(result);
}
#endif
return(Task.FromResult(result));
}
}
IList FilterFromKeys(IEnumerable <AnonType> keyTuples)
{
var result = new List <object>();
var key = Context.PrimaryKey;
var keyLength = key.Count;
foreach (var tuple in keyTuples)
{
if (result.Count > 0)
{
result.Add("or");
}
void AddCondition(IList container, int index)
{
container.Add(new object[] { key[index], tuple[index] });
}
if (keyLength == 1)
{
AddCondition(result, 0);
}
else
{
var group = new List <object>();
for (var i = 0; i < keyLength; i++)
{
AddCondition(group, i);
}
result.Add(group);
}
}
return(result);
}