Removing commented lines from InnerText - c#

i'm currently using the below code which extracts the InnerText, however, what happens is i'm stuck with a bunch of comment out lines of html <-- how do I remove these using the code below?
HtmlWeb hwObject = new HtmlWeb();
HtmlAgilityPack.HtmlDocument htmldocObject = hwObject.Load(htmlURL);
foreach (var script in htmldocObject.DocumentNode.Descendants("script").ToArray())
script.Remove();
HtmlNode body = htmldocObject.DocumentNode.SelectSingleNode("//body");
resultingHTML = body.InnerText.ToString();

Just filter the nodes by comment nodes and call remove on them.
var rootNode = doc.DocumentNode;
var query = rootNode.Descendants().OfType<HtmlCommentNode>().ToList();
foreach (var comment in query)
{
comment.Remove();
}

This is probably a better answer:
public static void RemoveComments(HtmlNode node)
{
foreach (var n in node.ChildNodes.ToArray())
RemoveComments(n);
if (node.NodeType == HtmlNodeType.Comment)
node.Remove();
}

Related

MVC StackOverflowException with larger html data

I have the following method (i'm using the htmlagilitypack):
public DataTable tableIntoTable(HtmlDocument doc)
{
var nodes = doc.DocumentNode.SelectNodes("//table");
var table = new DataTable("MyTable");
table.Columns.Add("raw", typeof(string));
foreach (var node in nodes)
{
if (
(!node.InnerHtml.Contains("pldefault"))
&& (!node.InnerHtml.Contains("ntdefault"))
&& (!node.InnerHtml.Contains("bgtabon"))
)
{
table.Rows.Add(node.InnerHtml);
}
}
return table;
}
It accepts html grabbed using this:
public HtmlDocument getDataWithGet(string url)
{
using (var wb = new WebClient())
{
string response = wb.DownloadString(url);
var doc = new HtmlDocument();
doc.LoadHtml(response);
return doc;
}
}
All works fine with an html document that is 3294 lines long.
When I feed it some html that is 33960 lines long I get:
StackOverflowException was unhandled at the IF statement in the tableIntoTable method as seen in this image:
http://imgur.com/Q2FnIgb
I thought it might be related to the MaxHttpCollectionKeys limit of 1000 so I tried putting this in my Web.config and it still doesn't work:
add key="aspnet:MaxHttpCollectionKeys" value="9999"
I'm not really sure where to go from here, it only breaks with larger html documents.
Assuming the values in your if statement are contained in some attribute value of some decendant of a table.
var xpath = #"//table[not(.//*[contains(#*,'pldefault') or
contains(#*,'ntdefault') or
contains(#*,'bgtabon')])]";
var tables = doc.DocumentNode.SelectNodes(xpath);
Upadte: More accurately based on your comments:
#"//table[not(.//td[contains(#class,'pldefault') or
contains(#class,'ntdefault') or
contains(#class,'bgtabon')])]";

C# HtmlDocument Extract Classes

I am writing some code to loop through every element in a HTML page and extract all ID and Classes.
My current code is able to extract the ID's but I can't see a way to get the classes, does anybody know where I can access these?
private void ParseElements()
{
// GET: Document from Browser
HtmlDocument ThisDocument = Browser.Document;
// DECLARE: List of IDs
List<string> ListIdentifiers = new List<string>();
// LOOP: Through Each Element
for (int LoopA = 0; LoopA < ThisDocument.All.Count; LoopA += 1)
{
// DETERMINE: Whether ID Exists in Element
if (ThisDocument.All[LoopA].Id != null)
{
// ADD: Identifier to List
ListIdentifiers.Add(ThisDocument.All[LoopA].Id);
}
}
}
You could get the inner HTML of each node and use a regular expression to get the class. Or you could try HTML Agility pack.
Something like...
HtmlAgilityPack.HtmlDocument AgilePack = new HtmlAgilityPack.HtmlDocument();
AgilePack.LoadHtml(ThisDocument.Body.OuterHtml);
HtmlNodeCollection Nodes = AgilePack.DocumentNode.SelectNodes(#"//*");
foreach (HtmlAgilityPack.HtmlNode Node in Nodes)
{
if (Node.Attributes["class"] != null)
MessageBox.Show(Node.Attributes["class"].Value);
}

HtmlAgilityPack HtmlNodeCollection returning NULL , shouldn't

I made a simple program for fetching youtube users in comments.
This is the code
string html;
using (var client = new WebClient())
{
html = client.DownloadString("http://www.youtube.com/watch?v=ER5EnjskCvE");
}
HtmlAgilityPack.HtmlDocument doc = new HtmlAgilityPack.HtmlDocument();
doc.LoadHtml(html);
List<string> data = new List<string>();
HtmlNodeCollection nodeCollection = doc.DocumentNode.SelectNodes("//*[#id='comments-view']/ul[1]/li[1]/a/span/span/span/span/img");
foreach (HtmlNode node in nodeCollection)
{
data.Add(node.GetAttributeValue("alt",null));
}
But i have a problem that my nodeCollection is returning null.
For the XPath i used copy XPath option in chrome under F12
try this replace "*" , "div"
"/html/body//div[#id='comments-view']/ul[1]/li[1]/a/span/span/span/span/img"

extract content from html page

I'm trying to extract the content inside div tag with id job_title1 in a html page. I'm using htmlagilitypack to fetch the data. Here is my code
var obj = new HtmlWeb();
var document = obj.Load("url of website ");
var bold = document.DocumentNode.SelectNodes("//div[#class='job_title1']");
foreach (var i in document.DocumentNode.SelectNodes("//div[#class='job_title1']"))
{
Response.Write(i.InnerHtml);
}
When i tried to run this code i'm getting error at foreach saying the Object reference not set to an instance of an object. Please help me solving this.
You said "div tag with id job_title1", shouldn't the xpath be:
document.DocumentNode.SelectNodes("//div[#id='job_title1']")
check if null like this:
var nodes = document.DocumentNode.SelectNodes("//div[#class='job_title1']");
if(nodes != null)
foreach (var i in document.DocumentNode.SelectNodes("//div[#class='job_title1']"
...
Edit: Use \" instead ':
var obj = new HtmlWeb();
var document = obj.Load("url of website ");
var bold = document.DocumentNode.SelectNodes("//div[#class=\"job_title1\"]");
if(bold!= null)
foreach (var i in bold)
{
Response.Write(i.InnerHtml);
}

Grab all text from html with Html Agility Pack

Input
<html><body><p>foo <a href='http://www.example.com'>bar</a> baz</p></body></html>
Output
foo
bar
baz
I know of htmldoc.DocumentNode.InnerText, but it will give foobarbaz - I want to get each text, not all at a time.
XPATH is your friend :)
HtmlDocument doc = new HtmlDocument();
doc.LoadHtml(#"<html><body><p>foo <a href='http://www.example.com'>bar</a> baz</p></body></html>");
foreach(HtmlNode node in doc.DocumentNode.SelectNodes("//text()"))
{
Console.WriteLine("text=" + node.InnerText);
}
var root = doc.DocumentNode;
var sb = new StringBuilder();
foreach (var node in root.DescendantNodesAndSelf())
{
if (!node.HasChildNodes)
{
string text = node.InnerText;
if (!string.IsNullOrEmpty(text))
sb.AppendLine(text.Trim());
}
}
This does what you need, but I am not sure if this is the best way. Maybe you should iterate through something other than DescendantNodesAndSelf for optimal performance.
I was in the need of a solution that extracts all text but discards the content of script and style tags. I could not find it anywhere, but I came up with the following which suits my own needs:
StringBuilder sb = new StringBuilder();
IEnumerable<HtmlNode> nodes = doc.DocumentNode.Descendants().Where( n =>
n.NodeType == HtmlNodeType.Text &&
n.ParentNode.Name != "script" &&
n.ParentNode.Name != "style");
foreach (HtmlNode node in nodes) {
Console.WriteLine(node.InnerText);
var pageContent = "{html content goes here}";
var pageDoc = new HtmlDocument();
pageDoc.LoadHtml(pageContent);
var pageText = pageDoc.DocumentNode.InnerText;
The specified example for html content:
<html><body><p>foo <a href='http://www.example.com'>bar</a> baz</p></body></html>
will produce the following output:
foo bar baz
public string html2text(string html) {
HtmlAgilityPack.HtmlDocument doc = new HtmlAgilityPack.HtmlDocument();
doc.LoadHtml(#"<html><body>" + html + "</body></html>");
return doc.DocumentNode.SelectSingleNode("//body").InnerText;
}
This workaround is based on Html Agility Pack. You can also install it via NuGet (package name: HtmlAgilityPack).
https://github.com/jamietre/CsQuery
have you tried CsQuery? Though not being maintained actively - it's still my favorite for parsing HTML to Text. Here's a one liner of how simple it is to get the Text from HTML.
var text = CQ.CreateDocument(htmlText).Text();
Here's a complete console application:
using System;
using CsQuery;
public class Program
{
public static void Main()
{
var html = "<div><h1>Hello World <p> some text inside h1 tag under p tag </p> </h1></div>";
var text = CQ.CreateDocument(html).Text();
Console.WriteLine(text); // Output: Hello World some text inside h1 tag under p tag
}
}
I understand that OP has asked for HtmlAgilityPack only but CsQuery is another unpopular and one of the best solutions I've found and wanted to share if someone finds this helpful. Cheers!
I just changed and fixed some people's answers to work better:
var document = new HtmlDocument();
document.LoadHtml(result);
var sb = new StringBuilder();
foreach (var node in document.DocumentNode.DescendantsAndSelf())
{
if (!node.HasChildNodes && node.Name == "#text" && node.ParentNode.Name != "script" && node.ParentNode.Name != "style")
{
string text = node.InnerText?.Trim();
if (text.HasValue() && !text.StartsWith('<') && !text.EndsWith('>'))
sb.AppendLine(System.Web.HttpUtility.HtmlDecode(text.Trim()));
}
}

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