XML Parsing Using DOM Parser in Apex.

Use the XmlNode class to work with a node in an XML document. The DOM represents an XML document as a hierarchy of nodes. Some nodes may be branch nodes and have child nodes, while others are leaf nodes with no children.

Node Types

There are different types of DOM nodes available in Apex. XmlNodeType is an enum of these different types. The values are:

COMMENT

ELEMENT

TEXT

It is important to distinguish between elements and nodes in an XML document. The following is a simple XML example:

<name>

    <firstName>Murali</firstName>

    <lastName>Mohan</lastName>

</name>

This example contains three XML elements: name, firstName, and lastName. It contains five nodes: the three name, firstName, and lastName element nodes, as well as two text nodes—Murali and Mohan. Note that the text within an element node is considered to be a separate text node.

Example to Parse the xml data or file Dynamically

VF Page :

<apex:page controller="Xmlparsercls" sidebar="false">

    <apex:form >

        <apex:pageBlock >

            <apex:pageBlockButtons location="bottom">

                <apex:commandButton value="Parse Xml" action="{!Parsexml}"/>    

                <apex:commandButton value="ParseXML File" action="{!Parsexmlfile}"/>

            </apex:pageBlockButtons>

            <apex:inputTextArea value="{!xmlstring}" style="width:336px;height:260px;"/> &nbsp;&nbsp;

            <apex:inputTextArea value="{!outxmlstring}" style="width:336px;height:260px;" id="response"/><br/>

            <apex:outputLabel value="Select Xml File" for="file"/>

            <apex:inputFile fileName="{!fileName}" value="{!body}"/>

        </apex:pageBlock>

    </apex:form>

</apex:page>

Controller :

public  class Xmlparsercls {

    public String xmlstring{get;set;}

    public String outxmlstring{get;set;}

    public String filename{get;set;}

    public blob body{get;set;}

    public Xmlparsercls(){

    }

//Parsing xml what you entered in the left text area

    public pagereference Parsexml(){

       outxmlstring ='';

       DOM.Document xmlDOC = new DOM.Document(); 

       xmlDOC.load(xmlstring); 

       DOM.XMLNode rootElement = xmlDOC.getRootElement();

       String result= walkThrough(rootElement);

       return null;

    }

  

  //This is for parsing xml file what you selected

  public pagereference Parsexmlfile(){

       outxmlstring ='';

       DOM.Document xmlDOC = new DOM.Document(); 

       xmlstring=body.tostring();

       system.debug('****xmlstring'+xmlstring);

       xmlDOC.load(xmlstring); 

       DOM.XMLNode rootElement = xmlDOC.getRootElement();

       String result= walkThrough(rootElement);

       return null;

    }

    

   Public String walkThrough(DOM.XMLNode node) {

        String result = '\n';

        if (node.getNodeType() == DOM.XMLNodeType.COMMENT) {

            return 'Comment (' +  node.getText() + ')';

        }

        if (node.getNodeType() == DOM.XMLNodeType.TEXT) {

            return 'Text (' + node.getText() + ')';

        }

        if (node.getNodeType() == DOM.XMLNodeType.ELEMENT) {

            

            if (node.getText().trim() != '') {

                outxmlstring += node.getName()+'=' +node.getText().trim()+'\n';

                String nName = node.getName();

            /*    if(nName == 'XXX')

                  {

                             String xxx = node.getText().trim();

                   }    */

            }

            if (node.getAttributeCount() > 0) { 

                for (Integer i = 0; i< node.getAttributeCount(); i++ ) {

                    result += ', attribute #' + i + ':' + node.getAttributeKeyAt(i) + '=' + node.getAttributeValue(node.getAttributeKeyAt(i), node.getAttributeKeyNsAt(i));

                }  

            }

            for (Dom.XMLNode child: node.getChildElements()) {

                result += walkThrough(child);

            }

            return result;

        }

        return '';

    }

}

OUTPUT :

When you are selecting file then click on ParseXML file button.

When you type as shown above in the textarea then click on "Parse Xml" button then you can parse the xml.