/// <summary>
/// Returns a tree node that is representative of an entity or.
/// </summary>
/// <param name="context">Context information about this query building session, including the target structured query object.</param>
/// <param name="allowReuse">A dedicated node should be returned because the caller intends on disturbing it.</param>
/// <returns>A query node that can be used within the query.</returns>
public override SQ.Entity OnBuildQueryNode(QueryBuilderContext context, bool allowReuse)
{
SQ.Entity result = context.ResolveParameterNode(ParameterName);
AddChildNodes(context, result, allowReuse);
return(result);
}
protected void AddChildNodes(QueryBuilderContext context, SQ.Entity parent, bool allowReuse)
{
context.ParentNodeStack.Push(parent);
foreach (var node in ChildContainer.ChildEntityNodes)
{
node.BuildQueryNode(context, allowReuse);
}
context.ParentNodeStack.Pop();
}
/// <summary>
/// Return true if we cannot
/// </summary>
/// <param name="node"></param>
/// <returns></returns>
private static bool NodeMightCauseSomeRowsToNotAppear(SQ.Entity node)
{
// Check flags on the node
RelatedResource relNode = node as RelatedResource;
if (relNode != null)
{
if (relNode.ResourceMustExist || relNode.CheckExistenceOnly || relNode.ConstrainParent)
{
return(true);
}
}
else
{
DownCastResource derivedNode = node as DownCastResource;
if (derivedNode != null)
{
if (derivedNode.MustExist)
{
return(true);
}
}
else
{
if (node is AggregateEntity)
{
return(false); // aggregates will always give us something
}
else
{
return(true);
}
}
}
// Check children
if (node.RelatedEntities.Any(NodeMightCauseSomeRowsToNotAppear))
{
return(true);
}
return(false);
}