Question

I have part of XmlDocument Example.xml as given below:

<rapaine dotoc='palin' domap='rattmin'>   <derif meet='local' />   <derif meet='intro' /> . . . </rapaine> 

Here i am creating a Nodelist and fetching the element raplin to get its attributes.

Now i want to make sure that whether the attributes ‘dotoc’ and ‘domap’ are the attributes of rapaine with respective values which are always fixed.Then only i can access the childNodes ‘deriff’ with its attribute ‘meet’. here the value only changes.
i have written a part of code there are no compile errors but on debugging i found that its not going inside the for loop to check its attributes and child nodes.

XmlNodeList listOfSpineRootNodes = opfXmlDoc.GetElementsByTagName('rapine'); for (int x = 0; x < listOfSpineRootNodes.Count; x++)   {     XmlAttributeCollection spineAttributes = listOfSpineRootNodes[x].Attributes;     string id = spineAttributes[0].Value;     if (spineAttributes != null)     {       XmlNode attrToc = spineAttributes.GetNamedItem('dotoc');       XmlNode attrPageMap = spineAttributes.GetNamedItem('domap');       if (attrToc.Value == 'palin' && attrPageMap.Value == 'rattmine')       {         if (listOfSpineRootNodes != null)         {           foreach (XmlNode spineNodeRoot in listOfSpineRootNodes)           {             XmlNodeList listOfSpineItemNodes = spineNodeRoot.ChildNodes;             if (listOfSpineItemNodes != null)             {               foreach (XmlNode spineItemNode in listOfSpineItemNodes)               {                 if (spineItemNode.NodeType == XmlNodeType.Element                   && spineItemNode.Name == 'derif')                 {                   XmlAttributeCollection spineItemAttributes = spineItemNode.Attributes;                    if (spineItemAttributes != null)                   {                     XmlNode attrIdRef = spineItemAttributes.GetNamedItem('meet');                     if (attrIdRef != null)                     {                       spineListOfSmilFiles.Add(attrIdRef.Value);                     }                   }                 }               }             }           }         }       }     } 

Can you please tell me where i am going wrong.. Thanks….

Answer 1

You can do this with the following code using XPath. Since XPath is a language designed specifically to query XML documents, you should consider learning it. Most newbies like to start learning at W3schools.

Here is the code:

XmlNodeList meetList = opfXmlDoc.SelectNodes('/rapaine[(@dotoc = 'palin') and (@domap = 'rattmin')]/derif/@meet') if (meetList.Count > 0) {   foreach (XmlNode meet in meetList)   {     spineListOfSmilFiles.Add(meet.Value);   } } 

For your reference, the XPath expression:

/rapaine[(@dotoc = 'palin') and (@domap = 'rattmin')]/derif/@meet 

can be explained as:

a) Find all rapaine root level elements that have an attribute dotoc with a value of ‘palin’ and also have an attribute domap with a value ‘rattmin’.

b) Within those rapaine elements, find all derif children.

c) Within those derif elements, retrieve all meet attributes.

Note how much more concise the code becomes.