CODEWITHSUNDEEP
c#web-crawlerhtml-agility-pack
user594166
user594166

Reputation:

get p tags that come after a specific tag using htmlagilitypack

I'm crawling a website using htmlagilitypack c#:

i have in the source code of an html page

....
<p>this a p that come before h3</p>
....
....
<h3>this h3 </h3>

<p>first p after h3</p>

....

<p>seconde p after h3</p>

i want to to all get all Ps that come after

is there a way to use a where to filter Ps using position.

where (position(p)>position(h3))

Upvotes: 1

Views: 2069

Answers (2)

tsubasa
tsubasa

Reputation: 11

Try the following code:

var htmlText = "source code of your html page";
var htmlDoc.LoadHtml(htmlText);
var h3= htmlDoc.DocumentNode.SelectNodes("//h2");
var lineNum = h3[0].Line;
var p = htmlDoc.DocumentNode.SelectNodes("//p").Where(x => x.Line > lineNum);

Upvotes: 1

Jeff Mercado
Jeff Mercado

Reputation: 134611

You could use a helper method such as this:

static IEnumerable<HtmlNode> FilteredTakeWhile(
    HtmlNode root,
    Func<HtmlNode, bool> predicate,
    Func<HtmlNode, bool> takePredicate)
{
    for (var currentNode = root.NextSibling;
         currentNode != null && takePredicate(currentNode);
         currentNode = currentNode.NextSibling)
    {
        if (predicate(currentNode))
            yield return currentNode;
    }
}

Then to use it:

var h3 = doc.DocumentNode.SelectSingleNode("h3");
// take all "p" nodes while we haven't reached the next "h3" node
var query = FilteredTakeWhile(h3, node => node.Name == "p", node => node.Name != "h3");

Upvotes: 2

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