I would like to know if there is a simple way to parse HTML in vb.net. I know that HTML is not sctrict subset of XML, but it would be nice if it could be treated that way. Is there anything out there that would let me parse HTML in an XML-like way in VB.net?
If you just want to parse HTML and your HTML is intended for the body of your document, you could do the following : (1) var div=document. createElement("DIV"); (2) div. innerHTML = markup; (3) result = div. childNodes; --- This gives you a collection of childnodes and should work not just in IE8 but even in IE6-7.
Parsing means analyzing and converting a program into an internal format that a runtime environment can actually run, for example the JavaScript engine inside browsers. The browser parses HTML into a DOM tree. HTML parsing involves tokenization and tree construction.
Which means that you can parse HTML documents after they have been modified by JavaScript. Both the JavaScript included in the page or a script you add yourself. The following example, from the documentation, shows a few features of AngleSharp.
'add prog ref too: Microsoft.mshtml
'then on the page:
Imports mshtml
Function parseMyHtml(ByVal htmlToParse$) As String
Dim htmlDocument As IHTMLDocument2 = New HTMLDocumentClass()
htmlDocument.write(htmlToParse)
htmlDocument.close()
Dim allElements As IHTMLElementCollection = htmlDocument.body.all
Dim allInputs As IHTMLElementCollection = allElements.tags("a")
Dim element As IHTMLElement
For Each element In allInputs
element.title = element.innerText
Next
Return htmlDocument.body.innerHTML
End Function
As found here:
I like Html Agility pack - it's very developer friendly, free and source code is available.
Don't use agility pack, just use mshtml library to access the dom, this is what ie uses and is great for going through HTML elements.
Agility pack is nasty and unnecessarily hackie if you ask me, mshtml is the way to go. Look it up on msdn.
If your HTML follows XHTML standards, you can do a lot of the parsing and processing using the System.XML namespace classes.
If, on the other hand, if what you're parsing is what web developers refer to as "tag soup," you'll need a third-party parser like HTML Agility Pack.
This may be only a partial solution to your problem if you're trying to figure out how a browser will interpret your HTML as each browser parses tag soup slightly differently.
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