Interactive Report count selected rows

Question

I have a I/R report with a checkbox is column 1 of each row using:
HTMLDB_ITEM.CHECKBOX
(1,R.RESEARCH_ID,
decode(:Pxx_SELECT_ALL_ROWS,'Y','CHECKED',
decode(instr(nvl(:Pxx_SELECTED_IDS,0),R.RESEARCH_ID),0,NULL,'CHECKED'))
AS select_flag
I want to use Javscript or a Dynamic Action to "count" how many selected rows there are, when a UPDATE button is pressed.
Right now, the UPDATE button "submits" the page, then a page item computation runs the following code to get a count:
DECLARE
v_cnt number(9);
BEGIN
v_cnt := 0;
FOR i in 1..htmldb_application.g_f01.count
LOOP
v_cnt := v_cnt + 1;
END LOOP;
return v_cnt;
This works... but I dont want to submit (and rerun the report) just to get this count.
I have copied this loop into a Dynamic Action using the Click action of the UPDATE button, but it doesnt seem to recognize htmldb_application.g_f01.count .. so my value returns as 0.
Any ideas - thanks!

Answer 1

I am not that strong in javascript, so I put a few alerts in the function you provided, to try to understand it better.
My example query returns 2 rows.
document.wwv_flow.f01.length returns a value = 2.
I checked both rows, then called the function.
I put an Alert inside the FOR loop in your example, it never executed.
The FOR loop in your example used a “>” sign, which never would evaluate as true, since i=0 > 2 is immediately false.
I changed the operator in the FOR loop to “<”.
The loop executed 2 times,
I displayed the with variable i : values = 0, 1
I displayed the value of document.wwv_flow.f01.id, it was NULL both iterations.
The $x(curr_id).checked is never true, so count remains = 0
function f_count_checked ()
var counter = 0;
for (var i = 0; i > document.wwv_flow.f01.length; i++) ---- I changed this to “<”
{var curr_id = document.wwv_flow.f01[i].id;
if ($x(curr_id).checked==true)
{counter = counter + 1;}}
alert ('You have checked: '+counter+' rows.');