protected internal override IEnumerable ExecuteSelect(DataSourceSelectArguments arguments)
{
ClearOriginalValues();
QueryContext queryContext = CreateQueryContext(arguments);
object table = GetSource(queryContext);
IList result = null;
if (_selectResult != null)
{
try {
IQueryable query = QueryableDataSourceHelper.AsQueryable(_selectResult);
query = ExecuteQuery(query, queryContext);
Type dataObjectType = GetDataObjectType(query.GetType());
result = query.ToList(dataObjectType);
if (_storeOriginalValues)
{
ITable dlinqTable = table as ITable;
// We can store original values if the type is exact or derived
if ((dlinqTable != null) && dataObjectType.IsAssignableFrom(EntityType))
{
StoreOriginalValues(result);
}
}
}
catch (Exception e) {
result = null;
LinqDataSourceStatusEventArgs selectedEventArgs = new LinqDataSourceStatusEventArgs(e);
OnSelected(selectedEventArgs);
OnException(new DynamicValidatorEventArgs(e, DynamicDataSourceOperation.Select));
if (!selectedEventArgs.ExceptionHandled)
{
throw;
}
}
finally {
if (result != null)
{
int totalRowCount = -1; // paging performed, but row count not available.
if (arguments.RetrieveTotalRowCount)
{
totalRowCount = arguments.TotalRowCount;
}
else if (!AutoPage)
{
totalRowCount = result.Count;
}
LinqDataSourceStatusEventArgs selectedEventArgs = new LinqDataSourceStatusEventArgs(result, totalRowCount);
OnSelected(selectedEventArgs);
}
}
// Null out the select context
Context = null;
}
return(result);
}
/// <summary>
/// Creates a select expression based on parameters and properties
/// </summary>
protected virtual IQueryable BuildQuery(DataSourceSelectArguments arguments)
{
if (arguments == null)
{
throw new ArgumentNullException("arguments");
}
// Create the query context
QueryContext context = CreateQueryContext(arguments);
// Clear out old values before selecting new data
_originalValues = null;
// Get the source of the query(root IQueryable)
object result = GetSource(context);
if (result != null)
{
IQueryable source = QueryableDataSourceHelper.AsQueryable(result);
// Apply additional filterting
return(ExecuteQuery(source, context));
}
return(null);
}