/// <summary>
/// Filter an element list using another selector. A null selector results in no filtering; an
/// empty string selector results in an empty list being return.
/// </summary>
///
/// <param name="elements">
/// The sequence to filter.
/// </param>
/// <param name="selector">
/// The selector.
/// </param>
///
/// <returns>
/// The filtered list.
/// </returns>
protected IEnumerable <IDomObject> FilterElementsIgnoreNull(IEnumerable <IDomObject> elements, string selector)
{
if (selector == "")
{
return(Objects.EmptyEnumerable <IDomObject>());
}
else if (selector == null)
{
return(elements);
}
else
{
Selector selectors = new Selector(selector).ToFilterSelector();
return(selectors.Filter(Document, elements));
}
}
//<summary>
// Filter an element list using another selector. A null selector results in no filtering.
//</summary>
//<param name="?"></param>
//<param name="selector"></param>
protected IEnumerable <IDomObject> filterElementsIgnoreNull(IEnumerable <IDomObject> elements, string selector)
{
if (selector == "")
{
return(Objects.EmptyEnumerable <IDomObject>());
}
else if (selector == null)
{
return(elements);
}
else
{
SelectorChain selectors = new SelectorChain(selector);
if (selectors.Count > 0)
{
selectors.Do(item => item.TraversalType = TraversalType.Filter);
}
// this is kind of unfortunate but is required to keep the order correct. Probably a more efficient
// way to do it but works fine for now
return(elements.Intersect(selectors.Select(Document, elements)));
}
}