Custom / manual pagination - batched collection report

Question

<p>I am trying to create a report with custom/manual pagination because I wish to implement a data access package where all request for data are via PL/SQL packaged functions returning Collections that represent the application data (i.e. no direct access to tables).</p>
<p>I pass in the 'Slice number' to the data access function - first fetch is Slice number = 1, second fetch is Slice number = 2 and so on. I can implement an On Submit Branch to increment a session state Slice number, but dont seem to be able to tie this to the Next Button, and therefore cannot decrease the Slice number when pressing the Previous button!!</p>
<p>I paste below sample SQL and PL/SQL code I am using.
Can you give me any tips / advices? Many thanks.</p>
<pre>create or replace type User_Objects_Obj as Object (
Owner varchar2(30),
Object_Name varchar2(128),
Object_Type varchar2(19),
Last_DDL_Time date
show errors;</pre>
<pre>create or replace type User_Objects_Vat as Varray(15) of User_Objects_Obj;
show errors;</pre>
<pre>create or replace package Data_Access_Pkg
as
function Get_User_Objects (Slice_No in integer)
return User_Objects_Vat;
end Data_Access_Pkg;
show errors;</pre>
<pre>create or replace package body Data_Access_Pkg
as
function Get_User_Objects (Slice_No in integer)
return User_Objects_Vat
as
User_Objects_Var User_Objects_Vat;
Slice_Size integer := 15;
lb integer := Slice_Size*(Slice_No - 1) + 1;
ub integer := lb + Slice_Size - 1;
begin
with Bounded as (
select 'X_User' as Owner, t.Object_Name, t.Object_Type, t.Last_DDL_Time
     ,Rownum r
     from User_Objects t
order by t.Object_Type, t.Object_Name
select User_Objects_Obj(
Bounded.Owner, Bounded.Object_Name
     ,Bounded.Object_Type, Bounded.Last_DDL_Time)
bulk collect into Get_User_Objects.User_Objects_Var
from Bounded
where Bounded.r between Get_User_Objects.lb and Get_User_Objects.ub;
return Get_User_Objects.User_Objects_Var;
end Get_User_Objects;
end Data_Access_Pkg;
show errors;</pre>
<p>I create a SQL Report Region and use this query (in the region source) to retrieve the collection of data;</p>
<pre>select Owner, Object_Name, Object_Type, Last_DDL_Time
from TABLE(
CAST(Data_Access_Pkg.Get_User_Objects(:P1001_SLICE_NO)
     AS User_Objects_Vat)
)</pre>

Answer 1

Hi Craig,
Sorry - yes, the setting of the next/previous vaules should be a process, well spotted!
In your report, if you click on the Region Footer heading to popup its help, you'll see that you have various values available to you:
#TIMING#
#ROWS_FETCHED# (items shown on the page)
#FIRST_ROW_FETCHED# (X in X-Y of Z in pagination)
#LAST_ROW_FETCHED# (Y in X-Y of Z in pagination)
#TOTAL_ROWS# (total rows in report - Z in X-Y of Z in pagination)
As these are only available AFTER the report has been generated, you can not easily use them to conditionally hide/show your next/previous buttons. However, you can use them within javascript to do this instead. For example (put this in the region footer for the report and change the button names to match yours):
&lt;script type="text/javascript"&gt;
var n = $('P1_NEXT_BUTTON');
var p = $('P1_PREVIOUS_BUTTON');
p.style.visibility = (#FIRST_ROW_FETCHED# == 1) ? 'hidden' : 'visible';
n.style.visibility = (#LAST_ROW_FETCHED# == #TOTAL_ROWS#) ? 'hidden' : 'visible';
&lt;/script&gt;So, if we're on the first page, the first row fetched will be row number 1, so we hide the Previous button, otherwise it is displayed. If we're on the last page, the last row fetched will match the total number of rows in the report, so we hide the Next button, otherwise it is displayed.
Andy