Bạn có thể tìm thấy commonness trong hầu như bất cứ điều gì. Ví dụ, "Tại sao là một bóng đèn như Doonesbury?" Không ai có thể huýt sáo. Chúng ta sẽ nhìn vào giao diện cho một máy in để chứng minh một loạt các sự cố kết. Tùy thuộc vào quan điểm của bạn, bạn có thể xem xét rằng tất cả các hoạt động máy in thuộc trong một giao diện, vì chúng đều liên quan đến in ấn. Hoặc bạn có thể | More on Document Style 98 The contents of ReserveOneWayAirfare could be shorter if the server were stateful. The server would need to remember what Selections had been transmitted. Then ReserveOneWayAirfare could contain just an index into the Selections of the QuotationForOneWayAirfare document. Once the travel site has confirmed your reservation the site returns a confirmation document Document Reservationconfirmation Reservation Identification Passenger FareAllInclusive Legs Flight Number Origin Destination DateTime Departure DateTime Arrival In the next step you pay for the reservation with the following document Document Payment Reservation Identification credit card Number credit card Information Amount And the system returns this Document PaymentReceived Reservation Identification The preceding documents communicate information between your web browser and the web server. on the web server side processing these documents may generate other documents such as requests for quotations to the individual reservation systems for each airline and charge documents to a credit card processor. Many other conditions may exist for this document sequence. For example you may have temporal constraints. If the Payment document is not received within a given period of time after ReservationConfirmation is sent the reservation may be canceled. A document flow can be expressed in procedural code. Assume each of the documents has been transformed into a corresponding DTo. You could code the sequence shown in Figure on the next page as follows RequestForQuotationForOneWayAirfare rfq Fill in rfq with desired values then QuotationForOneWayAirfare quotation send_message rfq Figure Document flow Put up GUI with selection ReserveOneWayAirfare reserve When user has selected an item fill in reserve and send it ReservationConfirmation confirmation send_message reserve Payment payment Fill in payment with amount and other information PaymentReceived payment_received send_message
