/// <summary>
/// Read OData item.
/// </summary>
/// <param name="reader">The odata reader.</param>
/// <param name="itemsStack">The item stack.</param>
/// <param name="topLevelItem">The top level item.</param>
private static void ReadODataItem(ODataReader reader, Stack <ODataItemWrapper> itemsStack, ref ODataItemWrapper topLevelItem)
{
Contract.Assert(reader != null);
Contract.Assert(itemsStack != null);
switch (reader.State)
{
case ODataReaderState.ResourceStart:
ReadResource(reader, itemsStack, ref topLevelItem);
break;
case ODataReaderState.DeletedResourceStart:
ReadDeletedResource(reader, itemsStack);
break;
case ODataReaderState.ResourceEnd:
Contract.Assert(itemsStack.Count > 0, "The resource which is ending should be on the top of the items stack.");
ODataResourceWrapper resourceWrapper = itemsStack.Peek() as ODataResourceWrapper;
if (resourceWrapper != null)
{
// Resource could be null
Contract.Assert(resourceWrapper.Resource == reader.Item, "The resource should be the same item in the reader.");
}
itemsStack.Pop();
break;
case ODataReaderState.DeletedResourceEnd:
Contract.Assert(itemsStack.Count > 0, "The deleted resource which is ending should be on the top of the items stack.");
ODataDeletedResourceWrapper deletedResourceWrapper = itemsStack.Peek() as ODataDeletedResourceWrapper;
Contract.Assert(deletedResourceWrapper != null, "The top object in the stack should be delete resource wrapper.");
Contract.Assert(deletedResourceWrapper.DeletedResource == reader.Item, "The deleted resource should be the same item in the reader.");
itemsStack.Pop();
break;
case ODataReaderState.NestedResourceInfoStart:
ODataNestedResourceInfo nestedResourceInfo = (ODataNestedResourceInfo)reader.Item;
Contract.Assert(nestedResourceInfo != null, "nested resource info should never be null.");
ODataNestedResourceInfoWrapper nestedResourceInfoWrapper = new ODataNestedResourceInfoWrapper(nestedResourceInfo);
Contract.Assert(itemsStack.Count > 0, "nested resource info can't appear as top-level item.");
{
ODataResourceBaseWrapper parentResource = (ODataResourceBaseWrapper)itemsStack.Peek();
parentResource.NestedResourceInfos.Add(nestedResourceInfoWrapper);
}
itemsStack.Push(nestedResourceInfoWrapper);
break;
case ODataReaderState.NestedResourceInfoEnd:
Contract.Assert(itemsStack.Count > 0, "The nested resource info which is ending should be on the top of the items stack.");
ODataNestedResourceInfoWrapper nestedInfoWrapper = itemsStack.Peek() as ODataNestedResourceInfoWrapper;
Contract.Assert(nestedInfoWrapper != null, "The top object in the stack should be nested resource info wrapper.");
Contract.Assert(nestedInfoWrapper.NestedResourceInfo == reader.Item, "The nested resource info should be the same item in the reader.");
itemsStack.Pop();
break;
case ODataReaderState.ResourceSetStart: // resource set
ReadResourceSet(reader, itemsStack, ref topLevelItem);
break;
case ODataReaderState.DeltaResourceSetStart: // delta resource set
ReadDeltaResourceSet(reader, itemsStack, ref topLevelItem);
break;
case ODataReaderState.ResourceSetEnd:
Contract.Assert(itemsStack.Count > 0, "The resource set which is ending should be on the top of the items stack.");
ODataResourceSetWrapper resourceSetWrapper = itemsStack.Peek() as ODataResourceSetWrapper;
Contract.Assert(resourceSetWrapper != null, "The top object in the stack should be resource set wrapper.");
Contract.Assert(resourceSetWrapper.ResourceSet == reader.Item, "The resource set should be the same item in the reader.");
itemsStack.Pop();
break;
case ODataReaderState.DeltaResourceSetEnd:
Contract.Assert(itemsStack.Count > 0, "The delta resource set which is ending should be on the top of the items stack.");
ODataDeltaResourceSetWrapper deltaResourceSetWrapper = itemsStack.Peek() as ODataDeltaResourceSetWrapper;
Contract.Assert(deltaResourceSetWrapper != null, "The top object in the stack should be delta resource set wrapper.");
Contract.Assert(deltaResourceSetWrapper.DeltaResourceSet == reader.Item, "The delta resource set should be the same item in the reader.");
itemsStack.Pop();
break;
case ODataReaderState.EntityReferenceLink:
ODataEntityReferenceLink entityReferenceLink = (ODataEntityReferenceLink)reader.Item;
Contract.Assert(entityReferenceLink != null, "Entity reference link should never be null.");
ODataEntityReferenceLinkWrapper entityReferenceLinkWrapper = new ODataEntityReferenceLinkWrapper(entityReferenceLink);
Contract.Assert(itemsStack.Count > 0, "Entity reference link should never be reported as top-level item.");
{
ODataNestedResourceInfoWrapper parentNestedResource = (ODataNestedResourceInfoWrapper)itemsStack.Peek();
Contract.Assert(parentNestedResource.NestedResourceSet == null, "Each reference nested property can not contain resource set as its direct child.");
Contract.Assert(parentNestedResource.NestedResource == null, "Each reference nested property can not contain resource as its direct child.");
parentNestedResource.AppendReferenceLink(entityReferenceLinkWrapper);
}
break;
case ODataReaderState.DeltaLink: // added link
case ODataReaderState.DeltaDeletedLink: // deleted link
ODataDeltaLinkBaseWrapper linkBaseWrapper;
if (ODataReaderState.DeltaLink == reader.State)
{
ODataDeltaLink deltaLink = (ODataDeltaLink)reader.Item;
Contract.Assert(deltaLink != null, "Delta link should never be null.");
linkBaseWrapper = new ODataDeltaLinkWrapper(deltaLink);
}
else
{
ODataDeltaDeletedLink deltaDeletedLink = (ODataDeltaDeletedLink)reader.Item;
Contract.Assert(deltaDeletedLink != null, "Delta deleted link should never be null.");
linkBaseWrapper = new ODataDeltaDeletedLinkWrapper(deltaDeletedLink);
}
Contract.Assert(itemsStack.Count > 0, "Delta link should never be reported as top-level item.");
// Should never add a delta link to a non-delta resource set.
ODataDeltaResourceSetWrapper linkResourceSetWrapper = (ODataDeltaResourceSetWrapper)itemsStack.Peek();
Contract.Assert(linkResourceSetWrapper != null, "ODataDeltaResourceSetWrapper for delta link should not be null.");
linkResourceSetWrapper.DeltaLinks.Add(linkBaseWrapper);
break;
default:
Contract.Assert(false, "We should never get here, it means the ODataReader reported a wrong state.");
break;
}
}
/// <summary>
/// Reads a <see cref="ODataResource"/> or <see cref="ODataResourceSet"/> object.
/// </summary>
/// <param name="reader">The OData reader to read from.</param>
/// <returns>The read resource or resource set.</returns>
public static ODataItemBase ReadResourceOrResourceSet(this ODataReader reader)
{
if (reader == null)
{
throw new ArgumentNullException(nameof(reader));
}
ODataItemBase topLevelItem = null;
Stack <ODataItemBase> itemsStack = new Stack <ODataItemBase>();
while (reader.Read())
{
switch (reader.State)
{
case ODataReaderState.ResourceStart:
ODataResource resource = (ODataResource)reader.Item;
ODataResourceWrapper resourceWrapper = null;
if (resource != null)
{
resourceWrapper = new ODataResourceWrapper(resource);
}
if (itemsStack.Count == 0)
{
Contract.Assert(resource != null, "The top-level resource can never be null.");
topLevelItem = resourceWrapper;
}
else
{
ODataItemBase parentItem = itemsStack.Peek();
ODataResourceSetWrapper parentResourceSet = parentItem as ODataResourceSetWrapper;
if (parentResourceSet != null)
{
parentResourceSet.Resources.Add(resourceWrapper);
}
else
{
ODataNestedResourceInfoWrapper parentNestedResource = (ODataNestedResourceInfoWrapper)parentItem;
Contract.Assert(parentNestedResource.NestedResourceInfo.IsCollection == false, "Only singleton nested properties can contain resource as their child.");
Contract.Assert(parentNestedResource.NestedItems.Count == 0, "Each nested property can contain only one resource as its direct child.");
parentNestedResource.NestedItems.Add(resourceWrapper);
}
}
itemsStack.Push(resourceWrapper);
break;
case ODataReaderState.ResourceEnd:
Contract.Assert(
itemsStack.Count > 0 && (reader.Item == null || itemsStack.Peek().Item == reader.Item),
"The resource which is ending should be on the top of the items stack.");
itemsStack.Pop();
break;
case ODataReaderState.NestedResourceInfoStart:
ODataNestedResourceInfo nestedResourceInfo = (ODataNestedResourceInfo)reader.Item;
Contract.Assert(nestedResourceInfo != null, "nested resource info should never be null.");
ODataNestedResourceInfoWrapper nestedResourceInfoWrapper = new ODataNestedResourceInfoWrapper(nestedResourceInfo);
Contract.Assert(itemsStack.Count > 0, "nested resource info can't appear as top-level item.");
{
ODataResourceWrapper parentResource = (ODataResourceWrapper)itemsStack.Peek();
parentResource.NestedResourceInfos.Add(nestedResourceInfoWrapper);
}
itemsStack.Push(nestedResourceInfoWrapper);
break;
case ODataReaderState.NestedResourceInfoEnd:
Contract.Assert(itemsStack.Count > 0 && itemsStack.Peek().Item == reader.Item,
"The nested resource info which is ending should be on the top of the items stack.");
itemsStack.Pop();
break;
case ODataReaderState.ResourceSetStart:
ODataResourceSet resourceSet = (ODataResourceSet)reader.Item;
Contract.Assert(resourceSet != null, "ResourceSet should never be null.");
ODataResourceSetWrapper resourceSetWrapper = new ODataResourceSetWrapper(resourceSet);
if (itemsStack.Count > 0)
{
ODataNestedResourceInfoWrapper parentNestedResourceInfo = (ODataNestedResourceInfoWrapper)itemsStack.Peek();
Contract.Assert(parentNestedResourceInfo != null, "this has to be an inner resource set. inner resource sets always have a nested resource info.");
Contract.Assert(parentNestedResourceInfo.NestedResourceInfo.IsCollection == true, "Only collection nested properties can contain resource set as their child.");
parentNestedResourceInfo.NestedItems.Add(resourceSetWrapper);
}
else
{
topLevelItem = resourceSetWrapper;
}
itemsStack.Push(resourceSetWrapper);
break;
case ODataReaderState.ResourceSetEnd:
Contract.Assert(itemsStack.Count > 0 && itemsStack.Peek().Item == reader.Item, "The resource set which is ending should be on the top of the items stack.");
itemsStack.Pop();
break;
case ODataReaderState.EntityReferenceLink:
ODataEntityReferenceLink entityReferenceLink = (ODataEntityReferenceLink)reader.Item;
Contract.Assert(entityReferenceLink != null, "Entity reference link should never be null.");
ODataEntityReferenceLinkBase entityReferenceLinkWrapper = new ODataEntityReferenceLinkBase(entityReferenceLink);
Contract.Assert(itemsStack.Count > 0, "Entity reference link should never be reported as top-level item.");
{
ODataNestedResourceInfoWrapper parentNavigationLink = (ODataNestedResourceInfoWrapper)itemsStack.Peek();
parentNavigationLink.NestedItems.Add(entityReferenceLinkWrapper);
}
break;
default:
Contract.Assert(false, "We should never get here, it means the ODataReader reported a wrong state.");
break;
}
}
Contract.Assert(reader.State == ODataReaderState.Completed, "We should have consumed all of the input by now.");
Contract.Assert(topLevelItem != null, "A top level resource or resource set should have been read by now.");
return(topLevelItem);
}
