Hide column in jqGrid display but show it in edit/add screen? - jqgrid

Question

In my jqGrid I want to pass in 5 rows from my model and display 3 of them in the grid but have all 5 show up in the edit and add popup window that jqGrid generates. I know I can add the hidden: true attribute in the colModel settings to prevent it from showing up but this also hides it from the popup window. Is there some way of hiding columns from the grid but show it when adding or editing data?
My Grid code:
<script type="text/javascript">
$( document ).ready( function ()
{
$( '#Sections' ).jqGrid( {
url: '#Url.Action("GetData")',
datatype: 'json',
mtype: 'GET',
colNames: ['ID', 'RouteName', 'Title', 'File', 'Description'],
colModel: [
{ name: 'ID', index: 'ID', width: 10, sorttype: 'int' },
{ name: 'RouteName', index: 'RouteName', width: 50, editable: true, edittype: 'text'},
{ name: 'Title', index: 'Title' },
{ name: 'File', index: 'File', hidden: true },
{ name: 'Description', index: 'Description', hidden: true }
],
autowidth: true,
height: '100%',
pager: $( '#SectionsPager' ),
sortname: 'ID',
viewrecords: true,
loadonce: true,
ignoreCase: true,
multiSort: true,
} );
$( '#Sections' ).jqGrid( 'navGrid', '#SectionsPager',
//enabling buttons
{ add: true, del: false, edit: true, search: true },
//add options
{ width: 'auto' },
//edit options
{ width: 'auto' },
//delete options
{}
);
} );
</script>

Answer 1

Via Oleg's answer at
Sending additional parameters to editurl on JQgrid
hidden: true, editable: true, editrules: { edithidden: true}, hidedlg: true
The editrules: { edithidden: true} section will "turn on" your column when editing.

Answer 2

u can use beforeShowForm in your add/edit and make it hidden or not
beforeShowForm: function(form) {
$("#tr_columnname").hide();
$("#tr_columnname").show();
}