Inside Web Dynpro for Java

Preface ... 15

1. Introduction ... 19
... 1.1 What is Web Dynpro? ... 19
... 1.2 What is the design philosophy behind Web Dynpro? ... 19
... 1.3 Improving the user's experience ... 19
... 1.4 Building a high-fidelity Web user interface ... 20
... 1.5 How is Web Dynpro different from other Web development tools? ... 20
... 1.6 What is the underlying design concept? ... 21

2. Designing a Web Dynpro application ... 27
... 2.1 Analysis phase ... 27
... 2.2 Design phase ... 27
... 2.3 Implementation phase ... 31

3. General architecture ... 33
... 3.1 Web Dynpro Framework ... 33
... 3.2 Application ... 33
... 3.3 Component ... 36
... 3.4 Controller ... 38
... 3.5 View ... 43
... 3.6 Model ... 46
... 3.7 Event handling ... 46

4. Web Dynpro naming placeholders ... 49
... 4.1 Development entities ... 49
... 4.2 Context entities ... 50
... 4.3 Generic and composite abbreviations ... 50
... 4.4 Subscripts for composite placeholders using the SAP recommended suffixes ... 51
... 4.5 J2EE Engine placeholders ... 51

5. Naming conventions ... 53
... 5.1 General rules for naming ... 53
... 5.2 Naming conventions for coding entities ... 56

6. The context ... 61
... 6.1 Context structure at design time ... 61
... 6.2 Context structure at runtime ... 66
... 6.3 Should node names be singular or plural? ... 72
... 6.4 General naming standards ... 73
... 6.5 Classes generated as a result of design time declarations ... 76
... 6.6 What's the difference between the various types of context nodes? ... 77
... 6.7 Fundamental principles of the context ... 82
... 6.8 Context mapping ... 84
... 6.9 Accessing the context through the typed API ... 91
... 6.10 Dynamic context manipulation ... 103

7. Coding principles in Web Dynpro ... 125
... 7.1 User-defined code ... 125
... 7.2 Problems with binding UI elements to context nodes ... 125
... 7.3 Building a context node hierarchy suitable for a tree UI element ... 127
... 7.4 Parameter mapping ... 131
... 7.5 Efficient use of actions to enable and disable UI elements ... 138
... 7.6 Layout managers ... 139
... 7.7 Principles for the efficient use of layout managers ... 146
... 7.8 Locale-specific text ... 147
... 7.9 Accessing any parameter in the query string ... 158

8. Dynamic UI generation ... 161
... 8.1 General points about Web Dynpro user interfaces ... 161
... 8.2 Background information about the design of UI elements ... 162
... 8.3 Accessing existing UI elements in a view layout ... 163
... 8.4 The principles of dynamic view construction ... 173
... 8.5 Dynamic Construction of a UI element hierarchy ... 176

9. The Common Model Interface ... 189
... 9.1 CMI terms and definitions ... 189
... 9.2 Access from a CMI object to the underlying business logic ... 191

10. The Adaptive RFC layer ... 193
... 10.1 General introduction to BAPIs ... 193
... 10.2 Custom written RFC modules ... 196
... 10.3 Background to the adaptive RFC layer ... 198
... 10.4 Introduction ... 201
... 10.5 Explanation of Generated Model Classes ... 204
... 10.6 Using model objects in a Web Dynpro controller ... 207
... 10.7 A simple example using context model nodes at runtime ... 211
... 10.8 Adapting to changes in an RFC interface ... 230
... 10.9 Connection management ... 238
... 10.10 Relationship between JCO destinations and ABAP sessions ... 247
... 10.11 Avoiding the Read-Write-Read problem ... 252
... 10.12 Why can't I use two different JCo connections? ... 255

11. Web Dynpro phase model ... 257
... 11.1 Transport data to DataContainer ... 258
... 11.2 Transport modified data into context ... 258
... 11.3 Validate modified data ... 258
... 11.4 Call system event handler ... 259
... 11.5 Call service event handler ... 259
... 11.6 Application event handler ... 260
... 11.7 doBeforeNavigation ... 260
... 11.8 Navigation and view initialization ... 260
... 11.9 Dynamic UI manipulation ... 261
... 11.10 doPostProcessing ... 261
... 11.11 Response rendering ... 262

12. Class and Interface Reference ... 263
... 12.1 Controllers, their methods, and self reference ... 263
... 12.2 Controller classes ... 266
... 12.3 Controller interfaces ... 271
... 12.4 Application interfaces ... 279
... 12.5 Context interfaces ... 279
... 12.6 View layout interfaces ... 299

A ABAP coding ... 343
B Dictionary structures ... 347
C The Author ... 349
Index ... 351