Web Services for PHP

Errors in SOAP should be returned as SOAP Faults. A SOAP Fault contains specific information detailing the reason for the Fault. PEAR::SOAP provides a SOAP_Fault class to aid in returning faults.

SOAP Fault in a SOAP Message

<SOAP-ENV:Fault>
         
<faultcode xsi:type="xsd:QName">
         SOAP-ENV:Client
</faultcode>
         
<faultstring xsi:type="xsd:string">
         You sent an empty string
</faultstring>
         
<faultactor xsi:type="xsd:anyURI">
         urn:SOAP_Example_Server
</faultactor>
         
<detail xsi:type="xsd:string"/>
         
</SOAP-ENV:Fault>

Faults can be of four basic types: VersionMismatch, MustUnderstand, Client and Server:

• VersionMismatch: invalid namespace for the SOAP Envelope

• MustUnderstand: a required header was not understood by the server

• Client: the message sent by the client was not properly formed, or did not contain the necessary information to fulfill the request.

• Server: the message could not be processed

Faults can also contain other information, such as a basic message describing the fault, the URI of the originator of the fault, and a detail field that can be used to provide additional information on the fault.