Custom function only for edit mode, not add mode, in jqGrid - jqgrid

Question

I have a jqGrid custom function as editrules: { custom: true, custom_func: checkforduplicates, required:true }
However, I want this function to be run only in add mode, not in edit mode. Is this possible ?
EDIT:- After answer below from Oleg, I changed code to below. However, the alert does not print. Not sure where I am going wrong.
colModel: [
{ key: true, name: 'id', editable: false, formatter: 'integer', viewable: false, hidden: true },
{
key: false,
name: 'name',
editable: true,
editrules: {
required: true,
custom: function (options) {
// options have the following properties
// cmName
// cm
// iCol
// iRow
// rowid
// mode - "editForm", "addForm", "edit", "add", "cell" and so on
// newValue - the value which need be validated
// oldValue - the old value
// some additional properties depends on the editing mode
alert("mode is " + options.mode);
if (options.mode === "add") { // "add" for inline editing
var grid = $("#grid");
var textsLength = grid.jqGrid("getRowData");
var textsLength2 = JSON.stringify(textsLength);
alert("i am here");
var myAttrib = $.map(textsLength,
function (item) { return item.name });
var count = 0;
for (var k in textsLength) {
if (textsLength.hasOwnProperty(k)) {
++count;
}
}
var text, i;
for (i = 0; i < count; i++) {
text = myAttrib[i];
if (value === text) {
return [false, " - Duplicate category name."];
}
}
return [true, ""];
}
return true;
}
}
},

Answer 1

Free jqGrid supports old style custom_func with the options value, name and iCol and the new style validation. To use new style validation one don't need to specify any custom_func callback, but to define custom as the calback function with one parameter:
editrules: {
required: true,
custom: function (options) {
// options have the following properties
// cmName
// cm
// iCol
// iRow
// rowid
// mode - "editForm", "addForm", "edit", "add", "cell" and so on
// newValue - the value which need be validated
// oldValue - the old value
// some additional properties depends on the editing mode
if (options.mode === "addForm") { // "add" for inline editing
// do the validation
}
return true;
}
}
In case of validation of Add form the mode property is equal to "addForm", options.iRow === -1, options.oldValue === null, options.rowid === "_empty". It's recommended to use options.mode to detect the editing (or searching mode) in free jqGrid because the values of other properties (iRow, oldValue and rowid) depends on the editing mode.

Answer 2

For version 4.7 I use this method. Form for adding data class for the table. After that, special actions verified by the user are performed.
{
name : "LOGIN",
index : "LOGIN", editrules: {
required:true,
custom:true,
custom_func: dublicateUser
}
...
{
closeAfterAdd : true,
width : 500,
recreateForm : true,
afterShowForm : function () {
jQuery("#TblGrid_list_users").addClass('addMode');
}
...
function dublicateUser() {
var a;
var login = jQuery('#LOGIN').val();
var checkMode = jQuery('#TblGrid_list_users').hasClass('addMode');
jQuery.ajax({
type: 'POST',
data: {login:login, mode:checkMode},
url: 'code/validate_user.php',
async: false,
success: function(data) {
if (data == 'err') {
a = 1;
}
else {
a=0;
}
}
});
if (a==1) {
return[false,"error"];
}
else {
return[true];
}
}