NWBC Application Context
When NWBC starts an application, it provides a startup parameter sap-nwbc-context ( CL_NWBC=>CONTEXT_HTTP_FORM_FIELD) on the URL. This parameter provides the application with information about the context in which the application was started. NWBC itself does not require the information, it is important only if this information is relevant to the started application.
All applications (or application frameworks) can retrieve this context and supply the startup context to NWBC within the started session with method CL_NWBC=>CONTEXT_SET_FROM_HTTP_REQUEST. The context string is stored statically within the session and can be retrieved at any time.
If the application is running stateless, the application should preserve the context string over roundtrips and re-initialize the string to NWBC at each time (if this context information is required). For Web Dynpro ABAP, these steps are already completed automatically by the Web Dynpro ABAP runtime, making the startup context available within the session for the application to reference.
The NWBC context can be retrieved at any time with the CL_NWBC=>CONTEXT_GET call. This method returns a structure with all relevant context information. (Note that in future the structure can be extended to contain more information.) Most importantly, directly after the context has been retrieved, the application should validate that a valid context does exist.
Example:
DATA: nwbc_context TYPE CL_NWBC=>T_CONTEXT.
nwbc_context = CL_NWBC=>CONTEXT_GET( ).
IF nwbc_context-valid = abap_true.
... here the rest of context can be referenced ...
ENDIF.
The following information is returned in the context:
|
Name |
Type |
Description |
|---|---|---|
|
valid |
abap_bool |
Set to abap_true if the NWBC context has been initialized for this ABAP session |
|
runtime_version |
string |
The value of the current ABAP runtime ( if_nwbc_runtime=>version) |
|
role_name |
string |
The name of the role that contains the application |
|
role_id |
string |
The ID of the entry within the role |
|
nwbc_shell |
string |
The current variant of active NWBC: either NWBC for Desktop ( CL_NWBC=>FOR_DESKTOP) or NWBC for HTML ( CL_NWBC=>FOR_HTML) |
|
canvas_window |
string |
Indicates the type of window in which the application has been started: main shell window ( CL_NWBC=>CANVAS__WINDOW__MAIN), an application window ( CL_NWBC=>CANVAS__WINDOW__APP) or an embedded window in an external portal ( CL_NWBC=>CANVAS__WINDOW__EMBEDDED) |
Web Dynpro ABAP