From the Library of sam kaplan in Java Implementation Code 128 Code Set A in Java From the Library of sam kaplan

From the Library of sam kaplan using barcode implement for awt control to generate, create code 128 image in awt applications. Windows Forms 9.5 DESKTOP FEATURES IN A STATELESS WEB 9.5 Desktop Features in a Stateless Web Workspaces and jar barcode standards 128 conversations are key concepts in Seam, setting Seam apart from previous generations of stateless web frameworks. It s easy to develop multiworkspace web applications using the rich set of Seam annotations and UI tags. However, web pages in a Seam conversation are typically not bookmarkable because they are tied together by HTTP POST requests with a lot of hidden eld data.

In the next chapter, we will discuss how to build bookmarkable RESTful URLs into your Seam application.. From the Library of sam kaplan This page intentionally left blank From the Library of sam kaplan Nested Conversations In previous chapters we have discussed a number of the features provided by the Seam conversation mo Code 128 for Java del. Long-running conversations provide a great mechanism for maintaining consistency of state in an application. Unfortunately, simply beginning and ending a long-running conversation is not always enough.

In certain situations, multiwindow operation and using the Back button can still result in inconsistencies between what the user sees and what the reality of the application s state is. Although we ve managed to segregate state within the HTTP session, there may be scenarios where the simple conversation model results in the same issues we faced with the HTTP session. This chapter will discuss the need for nested conversations through another variation of the Seam Hotel Booking example, the Nested Hotel Booking example.

The nestedbooking project can be found in the book s source code bundle. The Nested Hotel Booking example has the same directory setup as the Hello World and Natural Hotel Booking examples in the previous chapters (see Appendix B for the application template)..

10.1 Why Are Nested Conversations Needed In the booking Java Code 128C example we discussed in s 8 and 9, we might add a new requirement. Suppose a user can not only book hotels but, when booking a hotel, certain rooms may be available depending on the booking dates selected. In addition, the hotels would like us to provide in-depth descriptions of the rooms to entice users to upgrade their.

From the Library of sam kaplan CHAPTER 10 NESTED CONVERSATIONS Refactored booking screen that only requires entering check-in and check-out dates room preference jvm Code 128 Code Set B s. This would require inserting additional screens in our booking wizard. Selecting a hotel for booking is shown in Figure 10.

1. The Select Room button then sends the user to a list of available rooms, as shown in Figure 10.2.

The user can select any available room which will now appear as part of the booking package. Suppose the user opens another window with the room selection screen. In that screen, the user selects the Wonderful Room and proceeds to the con rmation screen.

In the other window, the user decides to see what it would be like to live the high life, selects the Fantastic Suite for booking, and again proceeds to con rmation. After reviewing the total cost, the user remembers that his or her credit card is near its limit! The user then returns to the window showing Wonderful Room and selects Con rm. Sounds familiar Being within a long-running conversation does not protect us from multiwindow operation within that conversation.

Just as with the HTTP session, if a conversation variable changes, that change affects all windows operating within the same conversation context. As a result, the user may be charged for a room upgrade that was not intended, leading to some serious credit card fees due to exceeding the credit limit and a nasty phone call to customer service..

From the Library of sam kaplan 10.2 CONTINUING THE CONVERSATION Additional room selection screen allowing the user to select a room for booking 10.2 Continuing the Conversation Seam s conversa tion model provides a simpli ed approach to continuations. If you are familiar with the concept of a continuation server, you are aware of the capabilities they provide, including seamless Back button operation and automatic state management. A user session has many continuations, which are simply snapshots of state during execution and can be reverted to at any time.

If you are not familiar with this concept, do not worry Seam makes it easy. The simple conversation model we discussed before is only part of the equation. In Seam, you also have the ability to nest conversations.

A conversation is simply a state container, as we saw in 8. Each booking occurs in its own conversation. As we saw before, based on the conversation ID, or cid for short, the appropriate hotel and booking will be injected each time the HotelBookingAction is accessed.

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