Manipulate XML

NarVish

Hi, In the below XML file, I would like add an element studentMarks with attribute Total=100, where the Student ID=101. I tried with InsertAfter method, but it didn't work. Please guide me, Thanks in advance.

<? xml version = “1.0″ encoding = “UTF-8″?>
<StudentRecords>
<SpecialStudent id=555>
<StudentName> John Trivolta </StudentName>
<StudentSubject> Science </StudentSubject>
<SpecialStudent>
<Student ID=100>
<StudentName> John Trivolta </StudentName>
<StudentSubject> Science </StudentSubject>
</Student>
<Student ID=101>
<StudentName> Bruce Lee </StudentName>
<StudentSubject> Computer </StudentSubject>
</Student>
<Student ID=102>
<StudentName> North V </StudentName>
<StudentSubject> Maths</StudentSubject>
</Student>
<StudentRecords>

NavnathKale

1. Get the XMLNode Student (of ID 101) 2. Get XMLNode StudentSubject 3. Call InsertAfter of Student node and pass StudentSubject node as reference node 4. And don't forget to save document If you this didn't help, post ur code here to analyse ;)

NarVish

Thanks for the reply. Please look at my code. I'm getting exception at below line. xmlDoc.DocumentElement.InsertAfter(newcatalogentry, refNode); Exception message: "The reference node is not a child of this node."

XmlTextReader xmlReader = new XmlTextReader(Application.StartupPath + "\\doc.xml");
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load(xmlReader);
xmlReader.Close();

        string xpath = string.Format("/StudentRecords/Student");
        XmlNamespaceManager nsmgr = new XmlNamespaceManager(xmlDoc.NameTable);
        XmlNodeList fieldNodes = xmlDoc.SelectNodes(xpath, nsmgr);
        string refName = "";
        int index = 0;
        XmlAttributeCollection ddd;
        XmlNode refNode = null;
        string studentID;
        foreach (XmlNode node in fieldNodes)
        {
            ddd = fieldNodes\[index\].Attributes;
            studentID = ddd\["ID"\].Value.ToString();
            
            if (Convert.ToInt32(studentID) == 101)
            {
                refNode = node.SelectSingleNode("StudentSubject");
            }
        }
        XmlDocument xmldoc = new XmlDocument();
        XmlElement newcatalogentry = xmldoc.CreateElement("StudentMarks");
        XmlAttribute newcatalogattr = xmldoc.CreateAttribute("Total");

        newcatalogattr.Value = "100";

        // Attach the attribute to the XML element
        newcatalogentry.SetAttributeNode(newcatalogattr);



        // New XML element inserted into the document
        xmlDoc.DocumentElement.InsertAfter(newcatalogentry, refNode);
        string path = "C:\\\\test.xml";
        FileStream fsxml = new FileStream(path, FileMode.Truncate,
                                          FileAccess.Write,
                                          FileShare.ReadWrite);
        xmlDoc.Save(path);

NavnathKale

XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load(Application.StartupPath + "\\doc.xml");

        string xpath = string.Format("/StudentRecords/Student");
        XmlNodeList fieldNodes = xmlDoc.SelectNodes(xpath);

        XmlNode studentNode = null;
        XmlNode refNode = null;
        
        foreach (XmlNode node in fieldNodes)
        {
            if (node.Attributes\["ID"\].Value == "101")
            {
                studentNode = node;
                refNode = node.SelectSingleNode("StudentSubject");
            }
        }

        if (studentNode != null && refNode != null)
        {
            XmlElement newcatalogentry = xmlDoc.CreateElement("StudentMarks");
            XmlAttribute newcatalogattr = xmlDoc.CreateAttribute("Total");

            newcatalogattr.Value = "100";

            // Attach the attribute to the XML element
            newcatalogentry.SetAttributeNode(newcatalogattr);

            // New XML element inserted into the document
            studentNode.InsertAfter(newcatalogentry, refNode);

            string path = "C:\\\\test.xml";
            
            xmlDoc.Save(path);
        }

updated within post area, test it at your end :cool:

NarVish

Thank you very much :)

NarVish

In the below xml, I would like to add this element

after

where student id=101. The below code is Please correct the below code.. its wrongly updating the xml. Thanks in advance..

<?xml version="1.0"?>
<StudentRecords>
<Student ID="100">
<StudentClass id="XA" name="XA" >
<StudentClass ref="F_HEIGHT" />
<StudentClass ref="F_WEIGHT" />
<StudentClass ref="F_STRENGTH" />
<StudentClass ref="F_LIBRARY" />
<StudentClass ref="F_QUALIFIER" />
</StudentClass>
</Student>
<Student ID="101">
<StudentClass id="XB" name="XB" >
<StudentClass ref="F_HEIGHT" />
<StudentClass ref="F_WEIGHT" />
<StudentClass ref="F_STRENGTH" />
<StudentClass ref="F_LIBRARY" /> </StudentClass>
</Student>
</StudentRecords>

XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load(Application.StartupPath :-D + "\\doc.xml");
string xpath = string.Format("/StudentRecords/Student");
XmlNodeList fieldNodes = xmlDoc.SelectNodes(xpath);
XmlNode studentNode = null;
XmlNode refNode = null;
foreach (XmlNode node in fieldNodes)
{
if (node.Attributes["ID"].Value == "101")
{
fieldNodes = xmlDoc.SelectNodes(xpath + "/StudentClass");
XmlNode node1 = fieldNodes.Item(0);
studentNode = node1;
refNode = node1.SelectSingleNode("StudentClass");
break;
}

        }            
        if (studentNode != null && refNode != null)            
        {
            XmlElement newcatalogentry = xmlDoc.CreateElement("StudentClass");
            XmlAttribute newcatalogattr = xmlDoc.CreateAttribute("ref");            
            newcatalogattr.Value = "F\_NewCategory";                
            // Attach the attribute to the XML element                
            newcatalogentry.SetAttributeNode(newcatalogattr);                
            // New XML element inserted into the document                
            studentNode.Inse

NavnathKale

        foreach (XmlNode node in fieldNodes)            
        {
            if (node.Attributes\["ID"\].Value == "101")    
            {
                fieldNodes = node.SelectNodes("/StudentClass");

                if (fieldNodes != null && fieldNodes.Count > 0)
                {
                    studentNode = fieldNodes.Item(0);

                    //loop thrugh all childNodes to get node with ref=F\_STRENGTH
                    foreach (XmlNode nodeClass in studentNode.ChildNodes)
                    {
                        if (nodeClass.Attributes\["ref"\].Value == "F\_STRENGTH")
                        {
                            refNode = nodeClass;
                            break;
                        }
                    }
                }
                break;
            }                       
        }

NarVish

The value of fieldNodes.Count is 0. so the condition failed in the below if condition

if (fieldNodes != null && fieldNodes.Count > 0)

NavnathKale

check line fieldNodes = node.SelectNodes("/StudentClass"); see other ways to get all StudentClass if it fails. else try this

        foreach (XmlNode node in fieldNodes)            
        {
            if (node.Attributes\["ID"\].Value == "101")    
            {
                studentNode = node\["StudentClass"\];

                if(studentNode != null)
                {
                    //loop thrugh all childNodes to get node with ref=F\_STRENGTH
                    foreach (XmlNode nodeClass in studentNode.ChildNodes)
                    {
                        if (nodeClass.Attributes\["ref"\].Value == "F\_STRENGTH")
                        {
                            refNode = nodeClass;
                            break;
                        }
                    }
                }
                break;
            }                       
        }

NarVish

Thank you, it worked..

NavnathKale

my pleasure :-D