The problem that I'm working with is that there is an exam that has sessions and each session has its applicants , I'm using JQgrid to select each session applicants
when I press select all check box then all rows in the page is selected whether the row is hidden or not .. the hidden rows are for different sessions and I'm hiding them to display them as selected if the user entered to the corresponding session
my question is .. how can I select all non hidden rows in a page .
I'd suggest you to disable hidden rows. Only non-disabled rows will be selected, even if you use select all rows.
Thus, I suggest you to add "disabled" or "ui-state-disabled" class to rows (<tr> elements) dependent on which CSS framework you use (Bootstrap or jQuery UI). By the way you can use rowattr callback to disable/hide rows.
P.S. If you use some very old version of jqGrid then you could require to use beforeSelectRow and onSelectAll callbacks instead of usage described above suggestion. See the old answer for more details.
