Question Reading from XML

[SmokingCookie]

Hi,

I'd like some help on this one, 'cause MSDN is (once again) very unclear.

I want to load an XML document, loop through all its nodes (Document.SelectNodes() ? ), retrieve the value of an attribute and its InnerText. Loading the document is no problem, but that's it; I cannot quite rely on MSDN's clarity.

Could someone please help me?
Thanks in advance

 

[daniella]

i have no idea if this is right or not, because i'm very new to this, but i just covered this subject today in my own project so may be able to help you?

imagine a hypothetical .XML file like:

<books_table>

<book>
<isbn>290239203</isbn>
<title>hello this is a book</title>
<author>me</author>
<class>classy</class>
</book>
</books table>

(only imagine loads of the nodes in there but i can't be bothered to type it up, sorry)


then imagine you have a windows application. add a list box (called listbox1) and a button ('list title and author')

double click the button to open the code editor + type this in:

Dim doc As New System.Xml.XmlDocument
doc.Load("C:\books.xml")

'add the following code to create an xmlnodelist from the <book> elements and their nested elements:

Dim nodes As System.Xml.XmlNodeList
nodes= doc.SelectNodes("Books_Table/book")

'now add a loop to display the text contained in each <title> and <author> element, then run the application

Dim counter = 0
Do Until counter = nodes.Count
    ListBox1.Items.Add(nodes.Item(counter) _
    .SelectSingleNode("title").InnerText & vbTab _
    & nodes.Item(counter) _
    .SelectSingleNode("author").InnerText & vbCrLf)
    counter += 1
Loop

then tweek it to fit your requirements/variable. you can delete the option to list two node elements but it's better to include two and delete rather than just have one? idkidk. GOOD LUCK xox

 

[SmokingCookie]

Hello,

You've just helped me solving 80% of the problem, thank you very much on that one

Now the other 20%: I am also trying to retrieve an attribute's value. So the XML would look like this:

<books_table>
<book ISBN="290239203">
<title>hello this is a book</title>
<author>me</author>
<class>classy</class>
</book>
</books_table>

Then retrieving the ISBN from the attribute is what remains. Have you got an idea of how that works?

EDIT::

Hmm.. Seems that changing a file path is bad.. I've changed it to D:\Books.xml (and moved the XML file), now I get some weird "file not found"-error.

A first chance exception of type 'System.IO.FileNotFoundException' occurred in System.Xml.dll

A first chance exception of type 'System.IO.FileNotFoundException' occurred in System.Xml.dll

 

[ohaidani]

ooh, i understand what you're asking but i have NO idea. i'm a complete newbie at this, i was amazed some one posted a question i could answer!

i know that the text between each <> is called 'innertext' so would outertext or something be worth a shot?

XML Tutorial

this website is REALLY detailed all about xml, so you might be able to find the name/reserved words regarding your problem and try and slot them in to replace 'innerword' or something? goodluckgoodluck! sorry i can't be of more help xxx

 

[JohnH]

Since you already have the node, get the attribute from the Attributes collection of the node.

 

[SmokingCookie]

Well, in JavaScript, I usually utilise DOMObject.getAttribute(name). I can't seem to find it in System.Xml. Does such a function exist?

 

[MattP]

Since you already have the node, get the attribute from the Attributes collection of the node.

Here's where JohnH was trying to point you.

		Dim doc As New XmlDocument
		doc.Load("C:\Temp\Books.xml")

		Dim nodes As XmlNodeList = doc.SelectNodes("books_table/book")

		For i As Integer = 0 To nodes.Count - 1
			With nodes.Item(i)
				Dim nodeText As String = String.Format("ISBN: {0}{1}Title: {2}{1}Author: {3}{1}", _
				 .Attributes("ISBN").Value, _
				 Environment.NewLine, _
				 .SelectSingleNode("title").InnerText, _
				 .SelectSingleNode("author").InnerText)
				MessageBox.Show(nodeText)
			End With
		Next

 

[SmokingCookie]

I see.

Unlike JavaScript, VB can (apparently) access collections directly (whereas I'm used to the Enumerator object to access them). That's probably what was the problem.

Here's where JohnH was trying to point you.

Pointing to doesn't really work for me