HtmlAgilityPack giving problems with malformed html
- by Kapil
I want to extract meaningful text out of an html document and I was using html-agility-pack for the same. Here is my code:
string convertedContent = HttpUtility.HtmlDecode(ConvertHtml(HtmlAgilityPack.HtmlEntity.DeEntitize(htmlAsString)));
ConvertHtml:
public string ConvertHtml(string html)
{
HtmlDocument doc = new HtmlDocument();
doc.LoadHtml(html);
StringWriter sw = new StringWriter();
ConvertTo(doc.DocumentNode, sw);
sw.Flush();
return sw.ToString();
}
ConvertTo:
public void ConvertTo(HtmlAgilityPack.HtmlNode node, TextWriter outText)
{
string html;
switch (node.NodeType)
{
case HtmlAgilityPack.HtmlNodeType.Comment:
// don't output comments
break;
case HtmlAgilityPack.HtmlNodeType.Document:
foreach (HtmlNode subnode in node.ChildNodes)
{
ConvertTo(subnode, outText);
}
break;
case HtmlAgilityPack.HtmlNodeType.Text:
// script and style must not be output
string parentName = node.ParentNode.Name;
if ((parentName == "script") || (parentName == "style"))
break;
// get text
html = ((HtmlTextNode)node).Text;
// is it in fact a special closing node output as text?
if (HtmlNode.IsOverlappedClosingElement(html))
break;
// check the text is meaningful and not a bunch of whitespaces
if (html.Trim().Length > 0)
{
outText.Write(HtmlEntity.DeEntitize(html) + " ");
}
break;
case HtmlAgilityPack.HtmlNodeType.Element:
switch (node.Name)
{
case "p":
// treat paragraphs as crlf
outText.Write("\r\n");
break;
}
if (node.HasChildNodes)
{
foreach (HtmlNode subnode in node.ChildNodes)
{
ConvertTo(subnode, outText);
}
}
break;
}
}
Now in some cases when the html pages are malformed (for example the following page - http://rareseeds.com/cart/products/Purple_of_Romagna_Artichoke-646-72.html has a malformed meta-tag like <meta content="text/html; charset=uft-8" http-equiv="Content-Type">) [Note "uft" instead of utf] my code is puking at the time I am trying to load the html document.
Can someone suggest me how can I overcome these malformed html pages and still extract relevant text out of a html document?
Thanks,
Kapil
