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);
}
private bool OriginalValueMatches(object originalValue, object value)
{
// NOTE: Comparing IEnumerable contents instead of instances to ensure that
// timestamp columns (of type byte[]) can be matched appropriately.
IEnumerable originalValueEnumerable = originalValue as IEnumerable;
IEnumerable valueEnumerable = value as IEnumerable;
if ((originalValueEnumerable != null) && (valueEnumerable != null))
{
return(QueryableDataSourceHelper.EnumerableContentEquals(originalValueEnumerable, valueEnumerable));
}
return(originalValue.Equals(value));
}
/// <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);
}
protected IQueryable ExecuteQueryExpressions(IQueryable source, QueryContext context)
{
if (source != null)
{
QueryCreatedEventArgs queryArgs = new QueryCreatedEventArgs(source);
OnQueryCreated(queryArgs);
source = queryArgs.Query ?? source;
// Support the Dynamic Expression language used by LinqDataSource
if (AutoGenerateWhereClause)
{
if (!String.IsNullOrEmpty(Where))
{
throw new InvalidOperationException(String.Format(CultureInfo.InvariantCulture,
AtlasWeb.LinqDataSourceView_WhereAlreadySpecified, _owner.ID));
}
source = QueryableDataSourceHelper.CreateWhereExpression(context.WhereParameters, source, _queryable);
}
else if (!String.IsNullOrEmpty(Where))
{
source = _queryable.Where(source, Where, context.WhereParameters.ToEscapedParameterKeys(_owner));
}
if (AutoGenerateOrderByClause)
{
if (!String.IsNullOrEmpty(OrderBy))
{
throw new InvalidOperationException(String.Format(CultureInfo.InvariantCulture,
AtlasWeb.LinqDataSourceView_OrderByAlreadySpecified, _owner.ID));
}
source = QueryableDataSourceHelper.CreateOrderByExpression(context.OrderByParameters, source, _queryable);
}
else if (!String.IsNullOrEmpty(OrderBy))
{
source = _queryable.OrderBy(source, OrderBy, context.OrderByParameters.ToEscapedParameterKeys(_owner));
}
string groupBy = GroupBy;
if (String.IsNullOrEmpty(groupBy))
{
if (!String.IsNullOrEmpty(OrderGroupsBy))
{
throw new InvalidOperationException(String.Format(CultureInfo.InvariantCulture,
AtlasWeb.LinqDataSourceView_OrderGroupsByRequiresGroupBy, _owner.ID));
}
}
else
{
source = _queryable.GroupBy(source, groupBy, "it", context.GroupByParameters.ToEscapedParameterKeys(_owner));
if (!String.IsNullOrEmpty(OrderGroupsBy))
{
source = _queryable.OrderBy(source, OrderGroupsBy, context.OrderGroupsByParameters.ToEscapedParameterKeys(_owner));
}
}
if (!String.IsNullOrEmpty(SelectNew))
{
source = _queryable.Select(source, SelectNew, context.SelectParameters.ToEscapedParameterKeys(_owner));
}
return(source);
}
return(source);
}
