Beispiel #1
0
        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();
        }