/// <summary>Initializes a new RequestDescription based on an existing one.</summary>
/// <param name="other">Other description to base new description on.</param>
/// <param name="resultExpression">Query results for new request description.</param>
/// <param name="rootProjectionNode">Projection segment describing the projections on the top level of the query.</param>
internal RequestDescription(
RequestDescription other,
Expression resultExpression,
RootProjectionNode rootProjectionNode)
{
Debug.Assert(
resultExpression == null || other.SegmentInfos != null,
"queryResults == null || other.SegmentInfos != null -- otherwise there isn't a segment in which to replace the query.");
Debug.Assert(
rootProjectionNode == null || resultExpression != null,
"rootProjectionNode == null || queryResults != null -- otherwise there isn't a query to execute and expand");
this.rootProjectionNode = rootProjectionNode;
this.containerName = other.ContainerName;
this.mimeType = other.MimeType;
this.resultUri = other.ResultUri;
this.segmentInfos = other.SegmentInfos;
this.CopyFrom(other);
if (resultExpression != null)
{
this.LastSegmentInfo.RequestExpression = resultExpression;
}
}
/// <summary>
/// Performs a depth-first walk down the expand tree, copying and adding to the current path as it goes. When the bottom of a path is reached, the path is added to the overall set of paths.
/// </summary>
/// <param name="currentPath">The current path so far for this depth-first traversal of the tree. Starts out null.</param>
/// <param name="currentNode">The current node of the expand tree.</param>
/// <param name="rootNode">The root node of the expand tree.</param>
private void ExtractExpandPathSegmentCollections(ExpandSegmentCollection currentPath, ExpandedProjectionNode currentNode, RootProjectionNode rootNode)
{
ExpandSegmentCollection nextPath = null;
foreach (ExpandedNavigationSelectItem expandItem in currentNode.SelectExpandClause.SelectedItems.OfType<ExpandedNavigationSelectItem>())
{
rootNode.ExpansionsSpecified = true;
if (currentPath == null)
{
nextPath = new ExpandSegmentCollection();
}
else
{
// create a copy of the current path.
nextPath = new ExpandSegmentCollection(currentPath.Count);
nextPath.AddRange(currentPath);
}
var segment = this.CreateExpandSegment(expandItem, currentNode.ResourceType);
nextPath.Add(segment);
ExpandedProjectionNode childNode = currentNode.AddExpandedNode(segment, expandItem.SelectAndExpand);
// if there are any derived expansions in the tree, set the rootNode.DerivedExpansionsSpecified to true.
if (currentNode.HasExpandedPropertyOnDerivedType)
{
rootNode.ExpansionOnDerivedTypesSpecified = true;
}
this.ExtractExpandPathSegmentCollections(nextPath, childNode, rootNode);
}
if (nextPath == null && currentPath != null)
{
this.expandPaths.Add(currentPath);
}
}
/// <summary>Initializes a new <see cref="RequestQueryProcessor"/> instance.</summary>
/// <param name="service">Service with data and configuration.</param>
/// <param name="description">Description for request processed so far.</param>
private RequestQueryProcessor(IDataService service, RequestDescription description)
{
this.service = service;
this.description = description;
#if DEBUG
this.orderApplied = false;
#endif
this.skipCount = null;
this.topCount = null;
this.queryExpression = description.RequestExpression;
this.setQueryApplicable = (description.TargetKind == RequestTargetKind.Resource && !description.IsSingleResult) ||
description.CountOption == RequestQueryCountOption.CountSegment;
// Server Driven Paging is not considered for the following cases:
// 1. Top level result is not or resource type or it is a single valued result.
// 2. $count segment provided.
// 3. Non-GET requests do not honor SDP.
// 4. Only exception for Non-GET requests is if the request is coming from a Service
// operation that returns a set of result values of entity type.
this.pagingApplicable = (description.TargetKind == RequestTargetKind.Resource && !description.IsSingleResult) &&
(description.CountOption != RequestQueryCountOption.CountSegment) &&
!description.IsRequestForEnumServiceOperation &&
(service.OperationContext.RequestMessage.HttpVerb.IsQuery() || description.SegmentInfos[0].TargetSource == RequestTargetSource.ServiceOperation);
this.appliedCustomPaging = false;
this.rootProjectionNode = null;
this.topLevelOrderingInfo = null;
this.skipTokenExpressionBuilder = new SkipTokenExpressionBuilder(NodeToExpressionTranslator.Create(this.service, description, Expression.Parameter(typeof(object))));
}
/// <summary>Gets the root projection node or creates one if no one exists yet.</summary>
/// <returns>The root node of the projection tree.</returns>
private RootProjectionNode GetRootProjectionNode()
{
if (this.rootProjectionNode == null)
{
// Build the root of the projection and expansion tree
this.rootProjectionNode = new RootProjectionNode(
this.description.LastSegmentInfo.TargetResourceSet,
this.topLevelOrderingInfo,
null,
this.skipCount,
this.topCount,
null,
this.expandPaths,
this.description.TargetResourceType,
this.description.ExpandAndSelect.Clause);
}
return this.rootProjectionNode;
}