/// <summary>
/// Create an Expand item using a nav prop, its entity set and a SelectExpandClause
/// </summary>
/// <param name="pathToNavigationProperty">the path to the navigation property for this expand item, including any type segments</param>
/// <param name="entitySet">the entity set for this ExpandItem</param>
/// <param name="selectExpandOption">This level select and any sub expands for this expand item.</param>
/// <exception cref="System.ArgumentNullException">Throws if input pathToNavigationProperty is null.</exception>
public ExpandedNavigationSelectItem(ODataExpandPath pathToNavigationProperty, IEdmEntitySet entitySet, SelectExpandClause selectExpandOption)
: this(pathToNavigationProperty, entitySet, null, null, null, null, null, selectExpandOption)
{
}
/// <summary>
/// Prune off any unneccessary expands
/// </summary>
/// <param name="clauseToPrune">the clause to prune</param>
/// <returns>a pruned tree.</returns>
internal static SelectExpandClause PruneSelectExpandTree(SelectExpandClause clauseToPrune)
{
DebugUtils.CheckNoExternalCallers();
// prune all child nodes first, then prune this node (Post-Order Tree traversal)
if (clauseToPrune == null)
{
return(null);
}
// if the selection on a clause is still unknown then it means it was expanded but never
// selected, in which case it should be pruned out of the tree.
if (clauseToPrune.Selection is UnknownSelection)
{
return(null);
}
if (clauseToPrune.Selection is AllSelection)
{
return(clauseToPrune);
}
if (clauseToPrune.Expansion != null)
{
List <ExpandedNavigationSelectItem> newChildExpandItems = new List <ExpandedNavigationSelectItem>();
// build a new list of child expand items for this level, pruning off any
// unneccessary expand items in the process.
foreach (ExpandedNavigationSelectItem childExpand in clauseToPrune.Expansion.ExpandItems)
{
SelectExpandClause newSubExpand = PruneSelectExpandTree(childExpand.SelectAndExpand);
if (newSubExpand == childExpand.SelectAndExpand)
{
newChildExpandItems.Add(childExpand);
}
else if (newSubExpand != null)
{
newChildExpandItems.Add(new ExpandedNavigationSelectItem(
childExpand.PathToNavigationProperty,
childExpand.EntitySet,
childExpand.FilterOption,
childExpand.OrderByOption,
childExpand.TopOption,
childExpand.SkipOption,
childExpand.InlineCountOption,
newSubExpand));
}
}
if (newChildExpandItems.Count == 0 && clauseToPrune.Selection is ExpansionsOnly)
{
return(null);
}
else
{
return(new SelectExpandClause(clauseToPrune.Selection, new Expansion(newChildExpandItems)));
}
}
else
{
if (clauseToPrune.Selection is ExpansionsOnly)
{
return(null);
}
else
{
return(clauseToPrune);
}
}
}
