SOAP Request Formatter

// SOAP 1.1 over fetch. Note SOAPAction: it is a separate header and its
// value must be quoted, even when it is empty.
const envelope = [
  '<?xml version="1.0" encoding="UTF-8"?>',
  '<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"',
  '               xmlns:ns="urn:example:orders">',
  '  <soap:Body>',
  '    <ns:GetOrder><ns:id>ORD-4471</ns:id></ns:GetOrder>',
  '  </soap:Body>',
  '</soap:Envelope>',
].join('\n');

const response = await fetch('https://example.com/orders', {
  method: 'POST',
  headers: {
    'Content-Type': 'text/xml; charset=utf-8',
    SOAPAction: '"urn:example:orders/GetOrder"',
    // SOAP 1.2 instead: no SOAPAction header, and
    // 'Content-Type': 'application/soap+xml; charset=utf-8; action="urn:example:orders/GetOrder"'
  },
  body: envelope,
});

// A fault arrives with HTTP 500 in SOAP 1.1, so response.ok is false and the
// body still holds the answer. Never throw on the status alone.
const text = await response.text();
const doc = new DOMParser().parseFromString(text, 'application/xml');
const SOAP11 = 'http://schemas.xmlsoap.org/soap/envelope/';
const fault = doc.getElementsByTagNameNS(SOAP11, 'Fault')[0];
if (fault) {
  // faultcode and faultstring are unqualified, even inside a qualified Fault.
  const code = fault.getElementsByTagName('faultcode')[0]?.textContent;
  const reason = fault.getElementsByTagName('faultstring')[0]?.textContent;
  throw new Error(code + ': ' + reason);
}

import requests
from defusedxml.ElementTree import fromstring   # never the stdlib parser here

SOAP11 = 'http://schemas.xmlsoap.org/soap/envelope/'
NS = {'soap': SOAP11, 'ns': 'urn:example:orders'}

envelope = """<?xml version="1.0" encoding="UTF-8"?>
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"
               xmlns:ns="urn:example:orders">
  <soap:Body>
    <ns:GetOrder><ns:id>ORD-4471</ns:id></ns:GetOrder>
  </soap:Body>
</soap:Envelope>"""

response = requests.post(
    'https://example.com/orders',
    data=envelope.encode('utf-8'),
    headers={
        'Content-Type': 'text/xml; charset=utf-8',
        'SOAPAction': '"urn:example:orders/GetOrder"',
    },
    timeout=30,
)

# Do not call raise_for_status(): a SOAP 1.1 fault is HTTP 500 and the body
# is the part you need.
root = fromstring(response.content)
fault = root.find('.//soap:Fault', NS)
if fault is not None:
    code = fault.findtext('faultcode')      # unqualified in SOAP 1.1
    reason = fault.findtext('faultstring')
    raise RuntimeError(f'{code}: {reason}')

# For a real client, zeep reads the WSDL and builds the envelope for you.
# This shape is for debugging one call, which is when you end up here.

import jakarta.xml.soap.*;   // javax.xml.soap before Jakarta EE 9
import java.io.ByteArrayOutputStream;

// SOAPConstants.SOAP_1_2_PROTOCOL for a 1.2 endpoint. The choice sets both
// the envelope namespace and the content type, so it is the one line that
// decides which version you are speaking.
MessageFactory factory = MessageFactory.newInstance(SOAPConstants.SOAP_1_1_PROTOCOL);
SOAPMessage message = factory.createMessage();

SOAPEnvelope envelope = message.getSOAPPart().getEnvelope();
envelope.addNamespaceDeclaration("ns", "urn:example:orders");

SOAPBody body = envelope.getBody();
SOAPElement call = body.addChildElement("GetOrder", "ns");
call.addChildElement("id", "ns").addTextNode("ORD-4471");

// SOAPAction, quoted, as a MIME header. SOAP 1.2 does not use it.
message.getMimeHeaders().addHeader("SOAPAction", "\"urn:example:orders/GetOrder\"");
message.saveChanges();

// The raw bytes on the wire: this is what you paste into a formatter.
ByteArrayOutputStream sent = new ByteArrayOutputStream();
message.writeTo(sent);
System.out.println(sent.toString("UTF-8"));

SOAPConnection connection = SOAPConnectionFactory.newInstance().createConnection();
SOAPMessage response = connection.call(message, "https://example.com/orders");

if (response.getSOAPBody().hasFault()) {
    SOAPFault fault = response.getSOAPBody().getFault();
    throw new RuntimeException(
        fault.getFaultCode() + ": " + fault.getFaultString());
}

using System.Net.Http;
using System.Net.Http.Headers;
using System.Text;
using System.Xml;
using System.Xml.Linq;

const string Soap11 = "http://schemas.xmlsoap.org/soap/envelope/";
XNamespace soap = Soap11;
XNamespace ns = "urn:example:orders";

var envelope = new XDocument(
    new XElement(soap + "Envelope",
        new XAttribute(XNamespace.Xmlns + "soap", Soap11),
        new XElement(soap + "Body",
            new XElement(ns + "GetOrder",
                new XElement(ns + "id", "ORD-4471")))));

using var http = new HttpClient();
var content = new StringContent(envelope.ToString(), Encoding.UTF8);
content.Headers.ContentType = new MediaTypeHeaderValue("text/xml")
{
    CharSet = "utf-8",
};
// SOAP 1.2 instead: media type application/soap+xml with an action parameter,
// and no SOAPAction header.
content.Headers.Add("SOAPAction", "\"urn:example:orders/GetOrder\"");

var response = await http.PostAsync("https://example.com/orders", content);
var body = await response.Content.ReadAsStringAsync();

// A fault is HTTP 500 with a real body, so do not call
// EnsureSuccessStatusCode() before you have looked at it.
var settings = new XmlReaderSettings
{
    DtdProcessing = DtdProcessing.Prohibit,
    XmlResolver = null,
};
using var reader = XmlReader.Create(new StringReader(body), settings);
var doc = XDocument.Load(reader);

var fault = doc.Descendants(soap + "Fault").FirstOrDefault();
if (fault is not null)
{
    // Unqualified children in SOAP 1.1: no namespace on the element name.
    var code = fault.Element("faultcode")?.Value;
    var reason = fault.Element("faultstring")?.Value;
    throw new InvalidOperationException(code + ": " + reason);
}

<?php
// trace => true is why this snippet exists: it is how you get the raw
// envelope to paste into a formatter and see what was actually sent.
$client = new SoapClient('https://example.com/orders?wsdl', [
    'trace'        => true,
    'exceptions'   => true,
    'soap_version' => SOAP_1_1,   // SOAP_1_2 changes the namespace and the
                                  // content type together
    'cache_wsdl'   => WSDL_CACHE_NONE,
    'stream_context' => stream_context_create([
        'ssl' => ['verify_peer' => true, 'verify_peer_name' => true],
    ]),
]);

try {
    $result = $client->GetOrder(['id' => 'ORD-4471']);
} catch (SoapFault $e) {
    // faultcode is the QName from the envelope, e.g. "soap:Client".
    fprintf(STDERR, "%s: %s\n", $e->faultcode, $e->getMessage());
} finally {
    // Both are null unless trace was enabled before the call.
    echo $client->__getLastRequest(), "\n";
    echo $client->__getLastResponse(), "\n";
}

# Capture a request and a response you can actually read. The SOAPAction
# value keeps its own quotes inside the header value.
curl -sS -D headers.txt \
  -H 'Content-Type: text/xml; charset=utf-8' \
  -H 'SOAPAction: "urn:example:orders/GetOrder"' \
  --data-binary @request.xml \
  https://example.com/orders \
  | tee response.xml | xmllint --format --nonet -

# SOAP 1.2: no SOAPAction header, the action rides on the content type.
curl -sS \
  -H 'Content-Type: application/soap+xml; charset=utf-8; action="urn:example:orders/GetOrder"' \
  --data-binary @request.xml \
  https://example.com/orders | xmllint --format --nonet -

# Was it a fault? Binding a namespace to xmllint --xpath is awkward, so match
# on the local name:
xmllint --nonet --xpath 'count(//*[local-name()="Fault"])' response.xml

# curl exits 0 on HTTP 500. Check the status line yourself:
head -1 headers.txt