What is the best way to create XML from a custom object and use that xml to create records of another custom object?

Question

I have two custom objects . How to transfer the records from one custom object to another using xml ?

Answer 1

If the names of the fields you are using are the same on both objects and you don't necessarily need to use XML, you could use JSON serialize and deserialize to change the object from one type to another in your Apex code:

Account a = new Account(name='The Object\'s Name');
system.debug(a);

String aString = JSON.serialize(a);
system.debug(aString);

Opportunity o = (Opportunity) JSON.deserialize(aString,Opportunity.class);
system.debug(o);

String oString = JSON.serialize(o);
system.debug(oString);

Answer 2

If you are planning to use XML, and parse it in Apex using DOM, then you could use following

public void parseData(String xmlString){ //Pass XML String

   /* e.g., xmlString = '<ObjectName>
                          <Attribute1>Value1</Attribute1>
                          <Attribute2>Value2</Attribute2>
                        </ObjectName>'; */
   Dom.Document doc = new Dom.Document();
   doc.load(xmlString);

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

    String attr1 = details.getChildElement('Attribute1', null).getText();
    String attr2 = details.getChildElement('Attribute2', null).getText();

    // print out specific elements
    System.debug('Attribute1: ' + Attribute1);
    System.debug('Attribute2: ' + Attribute2);

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

Referrences: here and here