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DeletingspecificAttributesinaXMLFile(ASP.NETv2)
I just wrote a small guestbook for my website and decided to use a XML file instead of a Database. I came accross several problems. That's how I solved them.
That's my example xml file:

<?xml version="1.0" encoding="utf-8"?>
<slGuestbook>
<entry name="testy" email="sersmail" location="locylocy" date="31.07.2005 14:45:11">exampletxt</entry>
<entry name="testy" email="testq" location="locylocy" date="31.07.2005 14:44:57">exampletxt</entry>
</slGuestbook>

that's my function:

public static XmlNode GetNode(XmlNode parentNode, string attrName, string attrValue)
    {
        XmlNode tmpNode = parentNode;
        XmlAttribute tmpAttr = null;


        while ((tmpAttr == null) && (tmpNode != null))
        {
            while ((tmpNode != null) && (tmpNode.LocalName != "entry"))
                tmpNode = slGuestbook.NextNode(tmpNode);

            try
            {
                tmpAttr = (XmlAttribute)tmpNode.Attributes.GetNamedItem(attrName);
                if (tmpAttr.Value == attrValue)
                {
                    return tmpNode;
                }
                else
                {
                    tmpAttr = null;
                    tmpNode = slGuestbook.NextNode(tmpNode);
                }
            }
            catch
            {
                tmpAttr = null;
            }
        }

        return tmpNode;
    }

    #region Method NextNode()
    /// <summary>
    /// Method to jump to next node. It´s irrelevant if next node is a child or parent node.
    /// </summary>
    /// <param name="actNode">Actual Node.</param>
    /// <returns>Next Node if exists, else null (end of XML!).</returns>
    public static XmlNode NextNode(XmlNode actNode)
    {
        if (actNode.HasChildNodes)
        {
            return actNode.FirstChild;
        }

        try
        {
            if (actNode.NextSibling != null)
            {
                actNode = actNode.NextSibling;
            }
            else
            {
                actNode = actNode.ParentNode;

                while (actNode.NextSibling == null)
                    actNode = actNode.ParentNode;

                actNode = actNode.NextSibling;
            }
        }
        catch
        {
            actNode = null;
        }
        return actNode;
    }
    #endregion

And that's how I call it:

        string path = Server.MapPath("~/xml/guestbook.xml");

        XmlDocument doc = new XmlDocument();
        doc.Load(path);
        XmlNode parentNode = doc.DocumentElement;
        XmlNode toDelete = slGuestbook.GetNode(parentNode, "email", "testq");
        parentNode.RemoveChild(toDelete);
        doc.Save(path);

That's working great for deleting specific guestbook entries. You can implent that call in any type of front-end to be able to delete entries on the fly.

Andreas Kraus
http://www.sunlab.de

Add by : Huobazi (2005-5-19:02:36)