XML Basics in Apex

Most modern APIs use JSON, but XML remains common in specific contexts: SOAP web services (next lesson), older enterprise systems, and some legacy government or financial integrations. Recognizing XML and knowing how to parse it is still a genuinely useful skill, even though JSON dominates newer integrations.

String xmlBody = '<response><status>success</status><rate>45.50</rate></response>';

DOM.Document doc = new DOM.Document();
doc.load(xmlBody);

DOM.XMLNode root = doc.getRootElement();
String status = root.getChildElement('status', null).getText();
Decimal rate = Decimal.valueOf(root.getChildElement('rate', null).getText());

1. String xmlBody = '<response><status>success</status><rate>45.50</rate></response>'; — raw XML text.
2. (blank line)
3. DOM.Document doc = new DOM.Document(); — a new, empty document.
4. doc.load(xmlBody); — parses the raw text into it.
5. (blank line)
6. DOM.XMLNode root = doc.getRootElement(); — the top-level <response> node.
7. String status = root.getChildElement('status', null).getText(); — navigates to <status> and reads its text.
8. Decimal rate = Decimal.valueOf(root.getChildElement('rate', null).getText()); — same for <rate>, converted from text to Decimal.

doc.load(xmlBody) parses the raw XML text; getRootElement() gives access to the top-level <response> node, and getChildElement(name, namespace) navigates down to a specific child — here, null for the namespace since this XML doesn't use one.

String xmlBody = '<order><items><item><name>Widget</name><qty>3</qty></item></items></order>';

DOM.Document doc = new DOM.Document();
doc.load(xmlBody);

DOM.XMLNode itemNode = doc.getRootElement().getChildElement('items', null).getChildElement('item', null);
String itemName = itemNode.getChildElement('name', null).getText();
Integer qty = Integer.valueOf(itemNode.getChildElement('qty', null).getText());

1. String xmlBody = '<order><items><item><name>Widget</name><qty>3</qty></item></items></order>'; — a more deeply nested XML document.
2. (blank line)
3. DOM.Document doc = new DOM.Document(); — a new document.
4. doc.load(xmlBody); — parses it.
5. (blank line)
6. DOM.XMLNode itemNode = doc.getRootElement().getChildElement('items', null).getChildElement('item', null); — chains three calls to reach the <item> node three levels down.
7. String itemName = itemNode.getChildElement('name', null).getText(); — one level further to <name>.
8. Integer qty = Integer.valueOf(itemNode.getChildElement('qty', null).getText()); — same for <qty>, converted to Integer.

Each getChildElement call navigates one level deeper — reading nested XML is a matter of chaining these calls to walk down the structure exactly the way the XML itself is nested.