// Build the projection tree given a select and expand and the entity set.
// TODO: Bug 467621: replace this with the ODataUriParser functionality
public static ODataQueryProjectionNode GetODataQueryProjectionNode(string selectQuery, string expandQuery, IEdmEntitySet entitySet)
{
IEnumerable <string> selects = (selectQuery ?? String.Empty).Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries).Select(s => s.Trim());
IEnumerable <string> expands = (expandQuery ?? String.Empty).Split(new[] { ',', }, StringSplitOptions.RemoveEmptyEntries).Select(s => s.Trim());
ODataQueryProjectionNode rootProjectionNode = new ODataQueryProjectionNode {
Name = String.Empty, NodeType = entitySet.ElementType
};
foreach (string expand in expands)
{
ODataQueryProjectionNode currentProjectionNode = rootProjectionNode;
IEnumerable <string> expandPath = expand.Split('/');
foreach (string property in expandPath)
{
ODataQueryProjectionNode nextNode = currentProjectionNode.Expands.SingleOrDefault(node => node.Name == property);
if (nextNode == null)
{
nextNode = new ODataQueryProjectionNode {
Name = property, NodeType = (currentProjectionNode.NodeType as IEdmEntityType).Properties().SingleOrDefault(p => p.Name == property).Type.Definition
};
currentProjectionNode.Expands.Add(nextNode);
}
currentProjectionNode = nextNode;
}
}
foreach (string select in selects)
{
ODataQueryProjectionNode currentProjectionNode = rootProjectionNode;
IEnumerable <string> selectPath = select.Split('/');
foreach (string property in selectPath)
{
ODataQueryProjectionNode nextNode = currentProjectionNode.Expands.SingleOrDefault(node => node.Name == property);
if (nextNode == null)
{
nextNode = new ODataQueryProjectionNode {
Name = property, NodeType = (currentProjectionNode.NodeType as IEdmEntityType).Properties().SingleOrDefault(p => p.Name == property).Type.Definition
};
currentProjectionNode.Selects.Add(nextNode);
}
currentProjectionNode = nextNode;
}
}
return(rootProjectionNode);
}
public override Task WriteToStreamAsync(Type type, object value, Stream writeStream, HttpContent content, TransportContext transportContext)
{
if (type == null)
{
throw Error.ArgumentNull("type");
}
if (writeStream == null)
{
throw Error.ArgumentNull("writeStream");
}
HttpContentHeaders contentHeaders = content == null ? null : content.Headers;
return(TaskHelpers.RunSynchronously(() =>
{
// Get the format and version to use from the ODataServiceVersion content header or if not available use the
// values configured for the specialized formatter instance.
ODataVersion version;
ODataFormat odataFormat;
if (contentHeaders == null)
{
version = _defaultODataVersion;
odataFormat = ODataFormatterConstants.DefaultODataFormat;
}
else
{
version = GetODataVersion(contentHeaders, ODataFormatterConstants.ODataServiceVersion) ?? _defaultODataVersion;
odataFormat = GetODataFormat(contentHeaders);
}
ODataSerializer serializer = ODataSerializerProvider.GetODataPayloadSerializer(type);
if (serializer == null)
{
throw Error.InvalidOperation(SRResources.TypeCannotBeSerialized, type.Name, typeof(ODataMediaTypeFormatter).Name);
}
if (IsClient)
{
// TODO: Bug 467617: figure out the story for the operation name on the client side and server side.
string operationName = (value != null ? value.GetType() : type).Name;
// serialize a request
IODataRequestMessage requestMessage = new ODataMessageWrapper(writeStream);
ODataResponseContext responseContext = new ODataResponseContext(requestMessage, odataFormat, version, new Uri(ODataFormatterConstants.DefaultNamespace), operationName);
ODataMessageWriterSettings writerSettings = new ODataMessageWriterSettings()
{
BaseUri = responseContext.BaseAddress,
Version = responseContext.ODataVersion,
Indent = responseContext.IsIndented,
DisableMessageStreamDisposal = true,
};
writerSettings.SetContentType(responseContext.ODataFormat);
using (ODataMessageWriter messageWriter = new ODataMessageWriter(requestMessage, writerSettings, Model))
{
ODataSerializerWriteContext writeContext = new ODataSerializerWriteContext(responseContext);
serializer.WriteObject(value, messageWriter, writeContext);
}
}
else
{
UrlHelper urlHelper = Request.GetUrlHelper();
NameValueCollection queryStringValues = Request.RequestUri.ParseQueryString();
IEdmEntitySet targetEntitySet = null;
ODataUriHelpers.TryGetEntitySetAndEntityType(Request.RequestUri, Model, out targetEntitySet);
ODataQueryProjectionNode rootProjectionNode = null;
if (targetEntitySet != null)
{
// TODO: Bug 467621: Move to ODataUriParser once it is done.
rootProjectionNode = ODataUriHelpers.GetODataQueryProjectionNode(queryStringValues["$select"], queryStringValues["$expand"], targetEntitySet);
}
// serialize a response
Uri baseAddress = new Uri(Request.RequestUri, Request.GetConfiguration().VirtualPathRoot);
// TODO: Bug 467617: figure out the story for the operation name on the client side and server side.
// This is clearly a workaround. We are assuming that the operation name is the last segment in the request uri
// which works for most cases and fall back to the type name of the object being written.
// We should rather use uri parser semantic tree to figure out the operation name from the request url.
string operationName = ODataUriHelpers.GetOperationName(Request.RequestUri, baseAddress);
operationName = operationName ?? type.Name;
IODataResponseMessage responseMessage = new ODataMessageWrapper(writeStream);
ODataResponseContext responseContext = new ODataResponseContext(responseMessage, odataFormat, version, baseAddress, operationName);
ODataMessageWriterSettings writerSettings = new ODataMessageWriterSettings()
{
BaseUri = responseContext.BaseAddress,
Version = responseContext.ODataVersion,
Indent = responseContext.IsIndented,
DisableMessageStreamDisposal = true,
};
if (contentHeaders != null && contentHeaders.ContentType != null)
{
writerSettings.SetContentType(contentHeaders.ContentType.ToString(), Encoding.UTF8.WebName);
}
using (ODataMessageWriter messageWriter = new ODataMessageWriter(responseMessage, writerSettings, ODataDeserializerProvider.EdmModel))
{
ODataSerializerWriteContext writeContext = new ODataSerializerWriteContext(responseContext)
{
EntitySet = targetEntitySet,
UrlHelper = urlHelper,
RootProjectionNode = rootProjectionNode,
CurrentProjectionNode = rootProjectionNode
};
serializer.WriteObject(value, messageWriter, writeContext);
}
}
}));
}
