internal static bool IsMatch(this HtmlAgilityPack.HtmlNode node, IEnumerable <SimpleSelector> selectors)
{
var stack = new Stack <SimpleSelector>(selectors);
var currentRule = stack.Pop();
if (!node.IsMatch(currentRule, stack))
{
return(false);
}
//no more selectors, its a match
if (!stack.Any())
{
return(true);
}
var currentNode = node.ParentNode;
currentRule = stack.Pop();
while (currentNode != null)
{
if (currentNode.IsMatch(currentRule, stack))
{
if (stack.Any())
{
currentRule = stack.Pop();
}
else
{
//no more rules left to match ad we still have ode context then return true
return(true);
}
}
//keep moving up the dom
currentNode = currentNode.ParentNode;
}
//We must still have unmatched css selectors
return(false);
}
internal static bool IsMatch(this HtmlAgilityPack.HtmlNode node, SimpleSelector selector, Stack <SimpleSelector> remainingStack)
{
if (!string.IsNullOrEmpty(selector.ElementName) && node.Name != selector.ElementName)
{
return(false);
}
if (!string.IsNullOrEmpty(selector.ID) && node.Id != selector.ID)
{
return(false);
}
if (!string.IsNullOrEmpty(selector.Class))
{
var classString = node.Attributes.Contains("class") ? node.Attributes["class"].Value : "";
if (!classString.Split(' ').Contains(selector.Class))
{
return(false);
}
}
if (!string.IsNullOrEmpty(selector.Pseudo))
{
if (!node.IsPseudoMatch(selector, remainingStack))
{
return(false);
}
}
if (selector.Combinator != null && remainingStack.Any())
{
var nextSel = remainingStack.Pop();
switch (selector.Combinator.Value)
{
case Combinator.ChildOf:
if (node.ParentNode == null) //has to be a child of something
{
return(false);
}
if (!node.ParentNode.IsMatch(nextSel, remainingStack))
{
return(false);
}
break;
case Combinator.Namespace:
//we are not going to support this until I see a valid use case
return(false);
case Combinator.PrecededBy:
if (!node.PreviousSiblingsNotText().Any(x => x.IsMatch(nextSel, remainingStack)))
{
return(false);
}
break;
case Combinator.PrecededImmediatelyBy:
var sib = node.PreviousSiblingNotText();
if (sib == null) //has to be a child of something
{
return(false);
}
if (!sib.IsMatch(nextSel, remainingStack))
{
return(false);
}
break;
default:
break;
}
}
if (selector.Attribute != null)
{
if (!node.IsMatch(selector.Attribute))
{
return(false);
}
}
if (selector.Child != null)
{
return(node.IsMatch(selector.Child, remainingStack));
}
return(true);
}
internal static IEnumerable <Selector> Matches(this HtmlAgilityPack.HtmlNode node, IEnumerable <Selector> selectors)
{
return(selectors.Where(x => node.IsMatch(x.SimpleSelectors)));
}