3.3.1. SOAP building module ¶

An SOAP message is a normal XML document that contains the following elements:

• Required Envelope element to identify this XML document as an SOAP message

• Optional Header element containing header information

• Required Body elements that contain all call and response information

• An optional Fault element that provides information about the error that occurred while processing this message

All of the above elements are declared in the default namespace for SOAP encapsulation:

http://www.w3.org/2001/12/soap-envelope

And the default namespace for SOAP encoding and data types:

http://www.w3.org/2001/12/soap-encoding

3.3.2. rule of grammar ¶

Here are some important grammar rules:

• SOAP messages must be encoded in XML

• SOAP messages must use the SOAP Envelope namespace

• SOAP messages must use the SOAP Encoding namespace

• SOAP messages cannot contain DTD references

• SOAP messages cannot contain XML processing instructions

3.3.3. The basic structure of SOAP messages ¶

<?xml version="1.0"?>
<soap:Envelope
xmlns:soap="http://www.w3.org/2001/12/soap-envelope"
soap:encodingStyle="http://www.w3.org/2001/12/soap-encoding">
<soap:Header>
...
</soap:Header>
<soap:Body>
...
  <soap:Fault>
  ...
  </soap:Fault>
</soap:Body>
</soap:Envelope>