/// <summary>
/// Enumerates items for a set of data objects of the specified type
/// with the specified restrictions and sort string, if supported.
/// </summary>
/// <param name="typeName">Name of the type of the object to enumerate.</param>
/// <param name="items">
/// The set of items to enumerate, specified as strings where named items are available,
/// otherwise as indexes. In cases in which a data provider does not support items
/// filtering, this parameter is ignored.
/// NOT SUPPORTED.
/// </param>
/// <param name="restrictions">
/// A set of filtering restrictions to apply to the set of returned objects.
/// </param>
/// <param name="sort">
/// A sort string, which follows syntax for the SQL Server ORDER BY clause.
/// The actual sort order should be source-based; that is, if the client is
/// English and the source is Chinese, the sort should be applied in Chinese.
/// NOT SUPPORTED.
/// </param>
/// <param name="parameters">
/// An array whose contents are defined by the given implementation of
/// EnumerateObjects, and which is specified by the Data Object Support
/// XML file. Information supplied in this parameter can be used to provide
/// extra data indicating how to perform the enumeration, allowing
/// implementations of this method to be more data driven.
/// NOT USED.
/// </param>
/// <returns>
/// Returns a DataReader object containing the results of the enumeration call.
/// </returns>
public override DataReader EnumerateObjects(
string typeName,
object[] items,
object[] restrictions,
string sort,
object[] parameters)
{
if (typeName == null)
{
throw new ArgumentNullException("typeName");
}
// Chose restricitions array
object[] appliedRestrictions;
if (typeName.Equals(RootDescriptor.TypeName, StringComparison.InvariantCultureIgnoreCase))
{
appliedRestrictions = new object[] {
ConnectionWrapper.ServerName,
ConnectionWrapper.Schema
};
}
else
{
appliedRestrictions = restrictions;
}
DataTable table;
try
{
// Enumerate objects into table
table = ObjectDescriptor.EnumerateObjects(ConnectionWrapper, typeName, appliedRestrictions, sort);
}
catch (DbException e)
{
SqlErrorDialog.ShowError(e, ConnectionWrapper.GetFullStatus());
throw;
}
catch (Exception e)
{
UIHelper.ShowError(e);
throw;
}
// Validate table
if (table == null)
{
Debug.Fail("Failed to enumerate objects of type '" + typeName + "'!");
return(null);
}
// Enumerete objects in to DataReader
return(new AdoDotNetDataTableReader(table));
}
