XML¹ is another popular format for serializing or exchanging structured data.

XML Decoding

You can decode an XML string into an XML object with the xml_decode() function.

Use the xml_xpath() function to extract values with XPath² queries.

{% set string_of_xml = 
"<response>
  <client_id>1</client_id>
  <invoice_id>123</invoice_id>
</response>"
-%}
{% set xml = xml_decode(string_of_xml) %}
{% set client_id = xml_xpath(xml, '//client_id')|first %}
{% set invoice_id = xml_xpath(xml, '//invoice_id')|first %}
Client ID: {{client_id}}
Invoice ID: {{invoice_id}}

Client ID: 1
Invoice ID: 123

XML Namespaces

You can define an XML namespace with the xml_xpath_ns() function:

{% set string_of_xml = 
"<response xmlns=\"http://www.example.com/api/\">
  <client_id>1</client_id>
  <invoice_id>123</invoice_id>
</response>"
-%}
{% set xml = xml_decode(string_of_xml) %}
{% set xml = xml_xpath_ns(xml, 'ns', 'http://www.example.com/api/') %}
{% set client_id = xml_xpath(xml, '//ns:client_id')|first %}
{% set invoice_id = xml_xpath(xml, '//ns:invoice_id')|first %}
Client ID: {{client_id}}
Invoice ID: {{invoice_id}}

Client ID: 1
Invoice ID: 123

XML Encoding

You can encode an object as XML with the xml_encode() function:

{% set string_of_xml = 
"<response xmlns=\"http://www.example.com/api/\">
  <client_id>1</client_id>
  <invoice_id>123</invoice_id>
</response>"
-%}
{% set xml = xml_decode(string_of_xml) %}
{{xml_encode(xml.client_id)}}	

<client_id>1</client_id>

References