public static SiteMapNode GetParentSiteMapNodeByLevel(this SiteMapNode childNode, int level)
{
//TODO: Unit test
// Pre-conditions
if (level < 0)
{
throw new ArgumentOutOfRangeException("level", "level cannot be negative");
}
if (childNode == null)
{
return(null);
}
const int rootLevel = 0;
if (level == rootLevel)
{
return(childNode.RootNode);
}
if (level == 1) // Short-cut for first non-root parent
{
if (childNode == SiteMap.RootNode)
{
return(null);
}
SiteMapNode result = childNode;
while ((result.ParentNode != null) && (result.ParentNode != childNode.RootNode))
{
result = result.ParentNode;
}
return(result);
}
int childNodeLevel = childNode.GetDepthLevel();
SiteMapNode currentLevelNode = childNode;
while (childNodeLevel > level)
{
currentLevelNode = currentLevelNode.ParentNode;
childNodeLevel--;
}
return(currentLevelNode);
}