WS-CAF Demo

A Demonstration of WS-CTX

WS-CAF In A Nutshell Collection of 3 specifications

WS-Context, WS-Coordination Framework and WS-Transaction Management

Designed to be used independently or together An open framework providing infrastructure support

for applications that contain multiple services used in combination (composite applications)

Enables composite applications to share common information

Provides a normal session for the web services environment

WS-CAF In The Web Services Protocol Stack

WS-Context In A Nutshell Allows composite applications to share common

information. Defines Notion of An Activity

Unit of work Session construct Shared scope of persistent data Basic context associated with activity

Defines web services for maintaining contexts 1 Activity per context Operations for creating, completing and getting

status of a context. Ability to pass contexts by reference or by value.

WS-Context In A Nutshell (cont’d) Practical uses include:

Distributed web sessions (less restricted form of standard web cookie)

Single sign-on Transaction propagation Processing of purchase order or travel

itineraries

The Context Structure An XML document containing a unique

identifier and optional data specific to a related activity.

Typically included in the SOAP header of messages to and from web services participating in an activity.

Can be passed as a referenceable URI (by reference) or in its longer form (by value)

Overview

Demo loosely based on WS-I Sample Apps Consists of implementations of WS-CTX

services and modified version of WS-I Sample App Retailer Service.

Demonstrates interoperability between context implementations

Each implementation has a web based UI that will be used as a driver for the demos.

WS-CTX Services Implemented ContextService

begin(beginMsg) complete(completeMsg) // context

passed in SOAP header UserContextService

begun(begunMsg) //context passed in SOAP header

completed(completedMsg) //context passed in SOAP header

Demo Flow

1) User selects a catalogue of items from any store implementation.

2) User selects items from catalogue and adds them to his cart.3) Store implementation begins new activity if there is no

current shopping cart held by the user (no context in header).

4) User can choose to add more items from the same or a different catalogue. Store implementations will add these items to the existing cart.

5) User decides to finalize sale, by selecting a store (not necessarily one he has added items from), and submitting his order.

6) Store implementation completes activity by calling complete on the ContextService referenced by the Context (using the context-service element).

Flow Example

User

Store 1

Store 2 CTX SVC. 2

CTX SVC. 11: getCatalog

2: addItemToCart

3: begin

4: submitOrder

5: complete