/// <summary>
/// Verifies that the query's typeusage will not result in a polymorphic result.
/// If the query would be restricted "is of only" using entityTypeFilter, then
/// this check assumes the result will not be polymorphic.
///
/// This method is only called if the user specifies EntitySetName and updates are enabled.
///
/// Does nothing for RowTypes.
/// </summary>
/// <param name="typeUsage">The TypeUsage from the query</param>
/// <param name="itemCollection"></param>
/// <returns></returns>
internal static void CheckNonPolymorphicTypeUsage(EntityType entityType,
ItemCollection ocItemCollection,
string entityTypeFilter)
{
CheckArgumentNull <ItemCollection>(ocItemCollection, "ocItemCollection");
if (String.IsNullOrEmpty(entityTypeFilter))
{
List <EdmType> types = new List <EdmType>(EntityDataSourceUtil.GetTypeAndSubtypesOf(entityType, ocItemCollection, /*includeAbstractTypes*/ true));
if (entityType.BaseType != null ||
types.Count() > 1 || entityType.Abstract)
{
throw new InvalidOperationException(Strings.EntityDataSourceUtil_EntityQueryCannotReturnPolymorphicTypes);
}
}
return;
}
internal EntityDataSourceWrapperCollection(ObjectContext context, EntitySet entitySet, EntityType restrictedEntityType)
{
EntityDataSourceUtil.CheckArgumentNull(context, "context");
EntityDataSourceUtil.CheckArgumentNull(entitySet, "entitySet");
_context = context;
_wrapperList = new List <EntityDataSourceWrapper>();
// get handles on the relevant workspaces
MetadataWorkspace csWorkspace = ((EntityConnection)context.Connection).GetMetadataWorkspace();
MetadataWorkspace ocWorkspace = context.MetadataWorkspace;
// if no restricted type is given, we assume the entity set element type is exposed
EntityType entityType = restrictedEntityType ?? entitySet.ElementType;
_clrEntityType = EntityDataSourceUtil.GetClrType(ocWorkspace, entityType);
// if no restricted type is given and the set is polymorphic, make the collection readonly
if (null == restrictedEntityType &&
1 < EntityDataSourceUtil.GetTypeAndSubtypesOf(entityType, csWorkspace.GetItemCollection(DataSpace.CSpace), true).Count())
{
_isReadOnly = true;
}
// gather the properties
ReadOnlyCollection <EntityDataSourceColumn> columns = EntityDataSourceUtil.GetNamedColumns(csWorkspace, ocWorkspace, entitySet, entityType);
List <PropertyDescriptor> visiblePropertyDescriptors = new List <PropertyDescriptor>(columns.Count);
List <EntityDataSourceWrapperPropertyDescriptor> propertyDescriptors = new List <EntityDataSourceWrapperPropertyDescriptor>(columns.Count);
foreach (EntityDataSourceColumn column in columns)
{
var descriptor = new EntityDataSourceWrapperPropertyDescriptor(this, column);
propertyDescriptors.Add(descriptor);
// if the descriptor does not have a dependent, it is exposed to the user
if (!descriptor.Column.IsHidden)
{
visiblePropertyDescriptors.Add(descriptor);
}
}
_visiblePropertyDescriptors = new PropertyDescriptorCollection(visiblePropertyDescriptors.ToArray(), true);
AllPropertyDescriptors = propertyDescriptors.AsReadOnly();
}
