static FetchRowsResult FetchRows(FetchRowsAsyncEventArgs e)
{
var queryable = GetIssueDataQueryable()
.SortBy(e.SortOrder, defaultUniqueSortPropertyName: "Id")
.Where(MakeFilterExpression(e.Filter));
return(queryable
.Skip(e.Skip)
.Take(e.Take ?? 30)
.ToArray());
}
static FetchRowsResult FetchRows(FetchRowsAsyncEventArgs e)
{
if (ReferenceEquals(e.Filter, null))
{
return(new FetchRowsResult(null, false));
}
var queryable = GetIssueDataQueryable().Where(MakeFilterExpression(e.Filter));
return(queryable
.Skip(e.Skip)
.Take(42)
.ToArray());
}
async Task <FetchRowsResult> FetchRowsAsync(FetchRowsAsyncEventArgs e)
{
IssueSortOrder sortOrder = IssuesHelper.GetIssueSortOrder(e);
IssueFilter filter = IssuesHelper.MakeIssueFilter(e.Filter);
const int pageSize = 30;
var issues = await IssuesService.GetIssuesAsync(
page : e.Skip / pageSize,
pageSize : pageSize,
sortOrder : sortOrder,
filter : filter);
return(new FetchRowsResult(issues, hasMoreRows: issues.Length == pageSize));
}
static async Task <FetchRowsResult> FetchRowsAsync(FetchRowsAsyncEventArgs e)
{
IssueSortOrder sortOrder = GetIssueSortOrder(e);
IssueFilter filter = MakeIssueFilter(e.Filter);
int take = e.Take ?? 30;
var issues = await IssuesService.GetIssuesAsync(
skip : e.Skip,
take : take,
sortOrder : sortOrder,
filter : filter);
return(new FetchRowsResult(issues, hasMoreRows: issues.Length == take));
}
static IssueSortOrder GetIssueSortOrder(FetchRowsAsyncEventArgs e)
{
if (e.SortOrder.Length > 0)
{
var sort = e.SortOrder.Single();
if (sort.PropertyName == "Created")
{
if (sort.Direction != ListSortDirection.Descending)
{
throw new InvalidOperationException();
}
return(IssueSortOrder.CreatedDescending);
}
if (sort.PropertyName == "Votes")
{
return(sort.Direction == ListSortDirection.Ascending
? IssueSortOrder.VotesAscending
: IssueSortOrder.VotesDescending);
}
}
return(IssueSortOrder.Default);
}
static async Task <FetchRowsResult> FetchRows(FetchRowsAsyncEventArgs e, Task <List <IssueData> > getSourceTask)
{
var enumerator = e.SkipToken as IEnumerator <IssueData>;
if (enumerator == null)
{
var data = await getSourceTask;
enumerator = Sort(data, e.SortOrder)
.Where(MakeFilterPredicate(e.Filter))
.GetEnumerator();
}
return(await Task.Run(() => {
var result = new List <IssueData>();
const int pageSize = 42;
while (enumerator.MoveNext() && result.Count < pageSize)
{
result.Add(enumerator.Current);
}
return new FetchRowsResult(result.ToArray(), hasMoreRows: result.Count == pageSize, nextSkipToken: enumerator);
}));
}
static FetchRowsResult FetchRows(FetchRowsAsyncEventArgs e)
{
var filterWithSkipToken = CriteriaOperator.And(e.Filter, (CriteriaOperator)e.SkipToken);
var converter = new GridFilterCriteriaToExpressionConverter <IssueData>();
var filterExpression = converter.Convert(filterWithSkipToken);
const string defaultUniqueSortProperty = "Id";
var context = new IssuesContext();
var queryable = IssueData.Select(context.Issues)
.SortBy(e.SortOrder, defaultUniqueSortPropertyName: defaultUniqueSortProperty)
.Where(filterExpression);
var issues = queryable
.Take(e.Take ?? 30)
.ToArray();
var nextSkipToken = SkipTokenHelper.MakeFilterSkipToken(e.SortOrder, defaultUniqueSortProperty, issues.LastOrDefault());
return(new FetchRowsResult(issues, nextSkipToken: nextSkipToken));
}
static IssueSortOrder GetIssueSortOrder(FetchRowsAsyncEventArgs e)
{
if (e.SortOrder.Length == 0)
{
return(IssueSortOrder.Default);
}
var sort = e.SortOrder.Single();
switch (sort.PropertyName)
{
case "Hot":
if (sort.Direction != ListSortDirection.Descending)
{
throw new InvalidOperationException();
}
return(IssueSortOrder.Hot);
case "Week":
if (sort.Direction != ListSortDirection.Descending)
{
throw new InvalidOperationException();
}
return(IssueSortOrder.Week);
case "Created":
return(sort.Direction == ListSortDirection.Ascending
? IssueSortOrder.CreatedAscending
: IssueSortOrder.CreatedDescending);
case "Votes":
return(sort.Direction == ListSortDirection.Ascending
? IssueSortOrder.VotesAscending
: IssueSortOrder.VotesDescending);
default:
return(IssueSortOrder.Default);
}
}
