Separate LI's by child element - html-agility-pack

Question

i have the following code:
HtmlAgilityPack.HtmlNodeCollection nodeCollection = bodyNode.SelectNodes("//ul[#class='myClass']//li");
which grabs about 250 LI's
the UL format is a bit weird and it goes like this:
<ul>
<li>
<h5>Parent</h5>
Some more tags here...
</li>
<li>
<h4>Child of the prev li</h4>
</li>
<li>
<h4>Child of the prev li</h4>
</li>
<!-- and so on -->
<!-- Then again -->
<li>
<h5>Parent</h5>
Some more tags here...
</li>
<li>
<h4>Child of the prev li</h4>
</li>
<li>
<h4>Child of the prev li</h4>
</li>
<!-- child li's are not constant, this is only for demo -->
</ul>
i need to separate the LI's into groups where each group contains the parent LI and all the children LI's
anyone can help with this?

Answer 1

If I understood correctly this is want you want
HtmlNodeCollection liList = doc.DocumentNode.SelectNodes("//ul//li");
List<List<HtmlNode>> liGroups = new List<List<HtmlNode>>();
List<HtmlNode> liGroup = null;
foreach (HtmlNode li in liList)
{
if (li.InnerText.Contains("Parent"))
{
if (liGroup != null)
liGroups.Add(liGroup);
liGroup = new List<HtmlNode>();
liGroup.Add(li);
}
else
{
liGroup.Add(li);
}
}
liGroups.Add(liGroup);
What you will have at the end is a list liGroups that will have other list liGroup. For your above html it will show that liGroups have 2 liGroup because in your above html you have 2 parents and both two liGroup will have 3 li (1 parent + 2 childs) because both parents have same amount of children.
After that you do with them whatever you want for example:
MessageBox.Show(liGroups[0][2].InnerText); //Show from the first group the 3rd's li InnerText

Answer 2

var tree = new Dictionary<HtmlNode, List<HtmlNode>>();
foreach (var node in nodeCollection)
if (node.SelectSingleNode("h5[text()='Parent']") != null)
tree.Add(node, new List<HtmlNode>());
else
tree.Last().Value.Add(node);
or
var groups = nodeCollection.Group();
static class Extensions
{
public static ILookup<HtmlNode, HtmlNode> Group(this HtmlNodeCollection collection)
{
return collection.Where(n => !n.IsParent()).ToLookup(n => n.GetParent());
}
public static bool IsParent(this HtmlNode node, string header = "Parent")
{
var h = node.Element("h5");
return h != null && h.InnerText == header;
}
public static HtmlNode GetParent(this HtmlNode node)
{
while (!node.IsParent())
node = node.PreviousSibling;
return node;
}
}