SOAP

1
SOAP

• Same basic functionality as XMLRPC but extensible
• complex data structures
• intermediate processing possible
• more support for classic RPC constructs
• http (not necessarily) provides connection
  management, framing, session

2
SOAP REQUEST

• (Examples from IBM Developerworks SOAP tutorial.
  See course resources page)
• http request must be POST
• http headers contain most of the control
• POST /calendar-request HTTP/1.1 Host
  uche.ogbuji.net Content-Type text/xml
  charset"utf-8" Content-Length 507
• SOAPAction "http//uche.ogbuji.net/soap-example"
  
• SOAPAction is a URN advising server, especially
  for routing, SOAP-aware firewalls, and other
  facilities. In Wrox example it is ""

3
HTTP Request Body

• SOAP Envelope containing SOAP body
• ltSOAP-ENVEnvelope xmlnsSOAP-ENV "http//schema
  s.xmlsoap.org/soap/envelope/" SOAP-ENVencodingSt
  yle http//schemas.xmlsoap.org/soap/encoding/"
  gt
• lt!-- SOAP body goes here --gt
• lt/SOAP-ENVEnvelopegt
• encodingStyle is the serialization schema it
  describes data types and other things telling how
  to interpret the body.

4
SOAP serialization

• encodingStyle often defaults as above but
  sometimes is rdf, XMLRPC, custom XML, or other
  things that validating parsers can deal with.
• "SOAP is like a set of Russian dolls in its
  layers of encapsulation. There are the HTTP
  headers, then the SOAP envelope, and then the
  SOAP body. Each layer provides metadata for the
  immediately enclosed layer.
• Metadata is information that helps an
  application make sense of the important data
  being transported. For instance, the HTTP header
  specifies the character encoding as metadata for
  the HTTP body. This makes sure that the
  application properly translates the stream of
  bits into a series of characters.
• The outermost portion of the HTTP body is the
  SOAP envelope. This contains the
  SOAP-ENVencodingStyle attribute which specifies
  the structure of the actual request. This
  metadata tells the application how to make sense
  of the XML elements and attributes within the
  body, which make up the actual request."
• IBM Developerworks SOAP Tutorial

5
SOAP Body

• IDL for a Calendar application
• module Calendar struct Date unsigned short
  day unsigned short month unsigned short
  year
• exception InvalidDate string field
• interface CalendarWidget void addListing(in
  Date when, in string what) raises
  (InvalidDate)
• string getListings(in Date monthOf) raises
  (InvalidDate)

6
SOAP Body

• Call the addListing service
• ltcAddListing xmlnsc"http//uche.ogbuji.net/so
  ap-example/calendar"gt
• lt!-- Request arguments go here -gt
• lt/cAddListinggt

7
SOAP request

• POST /calendar-request HTTP/1.1
• Host uche.ogbuji.net
• Content-Type text/plain charset"utf-8"
• Content-Length 507
• ltSOAP-ENVEnvelope xmlnsSOAP-NV"http//schemas.
  xmlsoap.org/soap/envelope/" SOAP-ENVencodingStyl
  e"http//schemas.xmlsoap.org/soap/encoding/" gt
• ltSOAP-ENVBodygt
• ltcAddListing xmlnsc"http//uche.ogbuji.net/so
  ap-example/calendar"gt
• ltcwhengt
• ltcDategt ltdaygt21lt/daygt
  ltmonthgt6lt/monthgt ltyeargt2001lt/yeargt
  lt/cDategt lt/cwhengt ltcwhatgtA total eclipse
  visible across Central Africa.lt/cwhatgtlt/cAddLis
  tinggt
• lt/SOAP-ENVBodygt lt/SOAP-ENVEnvelopegt

8
SOAP Response

• HTTP/1.1 200 OK Server PythonSimpleHTTP/2.0
  Date Tue, 28 Nov 2000 042303 GMT
  Content-type text/xml charset"utf-8"
  Content-length 296 ltSOAP-ENVEnvelope
  xmlnsSOAP-ENV"http//schemas.xmlsoap.org/soap/en
  velope/" SOAP-ENVencodingStyle
  "http//schemas.xmlsoap.org/soap/encoding/" gt
  ltSOAP-ENVBodygt ltcAddListingResponse
  xmlnsc"http//uche.ogbuji.net/soap-example/calen
  dar"/gt lt/SOAP-ENVBodygt lt/SOAP-ENVEnvelopegt