Sharing information between tiled view and view bean

Question

I have come across one more problem. I have a search result
page. This search result page has a static text field and a repeated group
(I simplified the page description, for explanation purpose). In the NetD
implementation they are maintaining a page level attribute (say boolean
haveSenisitiveCustomers) and setting this attribute in the
afterDataObjectExecute event. (This data object is associated with the
repeated). In end display event of static text field, they are displaying
message say " due to Registration type, not all customers meeting the
criteria are listed") if the haveSensitiveCustomers flag is set.
After Migration, the boolean flag and static Text Field movedto
SearchResultViewBean and afterDataObjectExecuteEvent has moved to
TiledViewBean. Actual processing done is more complicated than this
explanation. However, it boils down to sharing information between
tiledViewBean and its parent bean. How do we achieve this in the Migrated
Application?
One way is to add getter methods in the child tiled view bean( to
access in parent view bean, call getRepeated1 and cast to the actual type
and invoke the get methods)Probably the typical solution (I say typical because I don't yet know) will
be to do what you suggest: provide methods between views that can be used to
determine the state needed for processing like this.
However, let me alert you to something that's different than ND, and which
may cause you some trouble. In ND, all retrieving DataObjects associated
with a page executed at one time, and the afterDataObjectExcecuteEvent fired
before any display processing began. However, in JATO, tiled views are
independent objects, and any models associated with them only execute when
the tiled view is first displayed.
Therefore, if the static test field you refer to appears in the page before
the tiled view, then the tiled view will not have executed its associated
model before the static text field is rendered. You will never see the
static text field display the text you want because you won't have the
information at display time. (If the text field appears after the repeated,
then it's not problem, as the display of the tiled view will have executed
the associate model before the field displays.)
The solution is to manually reference the tiled view and its associate model
before they would normally execute. You would execute the model and set the
tiled view's setAutoRetrieveEnabled() to false to prevent it from executing
the model a second time. Perhaps the easiest thing to do would be this:
beforeStaticTextDisplay(...)
// Force the tiled view to execute the associated model
Repeated1TiledView tiledView=
(Repeated1TiledView)getChild("Repeated1");
tiledView.beginDisplay();
tiledView.setAutoRetrieveEnabled(false);
Although the beginDisplay() method will be executed twice in this case (once
deliberately, above, and later during actual display), there should be no
overhead. The beginDisplay() method doesn't do anything anyway except
execute associated auto-retrieving models and fire the
afterAllModelsExecute() event.
Mike, do you concur or have any comments?
This explanation rests on the understanding of a number of other subjects,
some of which you may not be fully familiar with. Feel free to ask further
questions about this explanation.
Todd
Todd Fast
Senior Engineer
Sun/Netscape Alliance
todd.fast@e...

Answer 1

I have come across one more problem. I have a search result
page. This search result page has a static text field and a repeated group
(I simplified the page description, for explanation purpose). In the NetD
implementation they are maintaining a page level attribute (say boolean
haveSenisitiveCustomers) and setting this attribute in the
afterDataObjectExecute event. (This data object is associated with the
repeated). In end display event of static text field, they are displaying
message say " due to Registration type, not all customers meeting the
criteria are listed") if the haveSensitiveCustomers flag is set.
After Migration, the boolean flag and static Text Field movedto
SearchResultViewBean and afterDataObjectExecuteEvent has moved to
TiledViewBean. Actual processing done is more complicated than this
explanation. However, it boils down to sharing information between
tiledViewBean and its parent bean. How do we achieve this in the Migrated
Application?
One way is to add getter methods in the child tiled view bean( to
access in parent view bean, call getRepeated1 and cast to the actual type
and invoke the get methods)Probably the typical solution (I say typical because I don't yet know) will
be to do what you suggest: provide methods between views that can be used to
determine the state needed for processing like this.
However, let me alert you to something that's different than ND, and which
may cause you some trouble. In ND, all retrieving DataObjects associated
with a page executed at one time, and the afterDataObjectExcecuteEvent fired
before any display processing began. However, in JATO, tiled views are
independent objects, and any models associated with them only execute when
the tiled view is first displayed.
Therefore, if the static test field you refer to appears in the page before
the tiled view, then the tiled view will not have executed its associated
model before the static text field is rendered. You will never see the
static text field display the text you want because you won't have the
information at display time. (If the text field appears after the repeated,
then it's not problem, as the display of the tiled view will have executed
the associate model before the field displays.)
The solution is to manually reference the tiled view and its associate model
before they would normally execute. You would execute the model and set the
tiled view's setAutoRetrieveEnabled() to false to prevent it from executing
the model a second time. Perhaps the easiest thing to do would be this:
beforeStaticTextDisplay(...)
// Force the tiled view to execute the associated model
Repeated1TiledView tiledView=
(Repeated1TiledView)getChild("Repeated1");
tiledView.beginDisplay();
tiledView.setAutoRetrieveEnabled(false);
Although the beginDisplay() method will be executed twice in this case (once
deliberately, above, and later during actual display), there should be no
overhead. The beginDisplay() method doesn't do anything anyway except
execute associated auto-retrieving models and fire the
afterAllModelsExecute() event.
Mike, do you concur or have any comments?
This explanation rests on the understanding of a number of other subjects,
some of which you may not be fully familiar with. Feel free to ask further
questions about this explanation.
Todd
Todd Fast
Senior Engineer
Sun/Netscape Alliance
todd.fast@e...