How to restrict the selection of number of choices for a List Collector Variable

[Aditya02]

I have a List Collector Variable, In this I want to restrict the selection of number of choices to two only. So, that user can able to select two options only. How to Perform this.

[piyushsain · Accepted solution]

I can see OnChange

[Aditya02]

thats great its working! but there is problem. After selection of third option i am getting alert box and at the same time the 3rd option was also selecting so, i want to remove that selections after the alert.

[piyushsain]

use g_form.removeOption(<fieldName>, <choiceValue>); get the choice value from the new value variable OR

use the code in this answer https://www.servicenow.com/community/itsm-forum/remove-just-single-value-from-selected-values-in-a-l...

[Aditya02]

The values are Not Clearing @piyushsain.

I am getting that alert that's all.

[Amit Verma]

Hi @Aditya02 

Try below On-Change Client Script :

function onChange(control, oldValue, newValue, isLoading) {
    if (isLoading || newValue == '') {
        return;
    }

    var values = g_form.getValue('requested_for').toString().split(',');
    var listCollector = g_list.get('requested_for');
    var selectedOptions = g_form.getValue('requested_for').split(',');

    if (values.length > 2) {

        alert('Please select only 2 values');

        var index = 0;
        for (var i = 1, leng = values.length + 1; i < leng; i++) {
            listCollector.removeItem(selectedOptions[selectedOptions.length - i]);
            index++;
        }
    }

}

Thanks & Regards

Amit Verma