/// <summary>
/// Retrieves the descendant children of specified object.
/// </summary>
/// <param name="service"></param>
/// <param name="o"></param>
/// <returns></returns>
public static IEnumerable <T> GetDescendants <T>(this IHierarchyService <T> service, T o)
{
ThrowIfInvalidArgs(service, o);
var stack = new Stack <T>(service.GetChildren(o).Reverse());
return(GetDescendantsAndSelf(service, stack));
}
/// <summary>
/// Returns a collection of the siblings after specified object.
/// </summary>
/// <param name="service"></param>
/// <param name="o"></param>
/// <returns></returns>
public static IEnumerable <T> GetObjectsAfterSelf <T>(this IHierarchyService <T> service, T o) where T : class
{
ThrowIfInvalidArgs(service, o);
var parent = service.GetParent(o);
if (parent != null)
{
return(service.GetChildren(parent).SkipWhile(c => c != o).Skip(1));
}
return(Enumerable.Empty <T>());
}
public async Task <VmPage <VmHierarchy> > GetChildren(int id)
{
var result = await _hierarchyService.GetChildren(id);
return(new VmPage <VmHierarchy>
{
Items = VmHierarchy.Build(result),
PageIndex = 1,
PageSize = 1,
TotalCount = result.Count
});
}
private static IEnumerable <T> GetDescendantsAndSelf <T>(this IHierarchyService <T> service, Stack <T> stack)
{
while (stack.Count > 0)
{
var o = stack.Pop();
yield return(o);
foreach (var child in service.GetChildren(o).Reverse())
{
stack.Push(child);
}
}
}
/// <summary>
/// Determines whether the object has grandchildren.
/// </summary>
/// <param name="service"></param>
/// <param name="o"></param>
/// <returns></returns>
public static bool HasGrandchildren <T>(this IHierarchyService <T> service, T o)
{
ThrowIfInvalidArgs(service, o);
return(service.GetChildren(o).Any(c => !service.IsLeaf(c)));
}
/// <summary>
/// Determines whether the object is a leaf object, meaning it has no children.
/// </summary>
/// <param name="service"></param>
/// <param name="o"></param>
/// <returns></returns>
public static bool IsLeaf <T>(this IHierarchyService <T> service, T o)
{
ThrowIfInvalidArgs(service, o);
return(!service.GetChildren(o).Any());
}