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Designing XML Based Applications

 Account Processing

 Workflow 

 XML 

Credit Card 

Dispatching 

Document 

Processing

Logic

 Airline Reservation 

Processing

Figure 4.9

Fragmenting an Incoming XML Document for a Travel Service

E

Rather than pass the entire document to different components handling various 

stages of the business process, it's best if the processing logic breaks the doc 

ument into fragments and passes only the required fragments to other compo 

nents or services that implement portions of the business process logic. 

Figure 4.9 shows how the processing layer might process an XML document

representing an incoming purchase order for a travel agency Web service. The

document contains details such as account information, credit card data, travel

destinations, dates, and so forth. The business logic involves verifying the

account, authorizing the credit card, and filling the airline and hotel portions of the

purchase order. It is not necessary to pass all the document details to a business

process stage that is only performing one piece of the business process, such as

account verification. Passing the entire XML document to all stages of the busi 

ness process results in unnecessary information flows and extra processing. It is

more efficient to extract the logical fragments account fragment, credit card