[SalesForce] XML parsing in Apex

As per the Apex documentation here, you use the getAttributeLocalName method to determine this, but only on start element or attribute element events. Adapting the sample given in the documentation you can see this method in action below.

while(reader.hasNext()) {
    if (reader.getEventType() == XmlTag.START_ELEMENT) {
        if ('UDF' == reader.getLocalName()) {
            System.debug(reader.getAttributeValue(null, 'name'));
        }
    }
    reader.next();
} 

Text Handling. If you want to retrieve the test content of an element, you need to call getText() but only hasTest() returns true, e.g. when getEventType() == XmlTag.Characters. The documentation states that hasText() returns true and thus getText() works only when...

Returns true if the current event has text, false otherwise The following XML events have text: characters, entity reference, comment and space.

This post from salesforce.com explains in detail with an example on how to work with XML data in apex.

Edit

I have just used the same code as provided in the link and it should work.

public class DomDocument {

    // Pass in the URL for the request
    // For the purposes of this sample,assume that the URL
    // returns the XML shown above in the response body
    public void parseResponseDom(String url){

       string xml = '<OrderDetails>
                            <OrderDetailID>2584</OrderDetailID>
                            <GiftWrapCost>0.0000</GiftWrapCost>
                            <GiftWrapNote/>
                            <ProductCode>800006</ProductCode> 
                           </OrderDetails>';
       Dom.Document doc = new Dom.Document();
       doc.load(xml);

        //Retrieve the root element for this document.
        Dom.XMLNode ordDtls = doc.getRootElement();

        String OrderDetailId= ordDtls.getChildElement('OrderDetailId', null).getText();
        String prdCode = ordDtls.getChildElement('ProductCode', null).getText();
        // print out specific elements
        System.debug('OrderDtlID: ' + OrderDetailId);
        System.debug('Prod Code: ' + prdCode );

        // Alternatively, loop through the child elements.
        // This prints out all the elements of the address
        for(Dom.XMLNode child : ordDtls.getChildElements()) {
           System.debug(child.getText());
        }
    }
}