How to check is an attachment has been added to a request

[Nikkikobako]

Hi I have used a number of suggestions I found online to check if an attachment is attached but most just error. The closest i get is below I check first if a selection is yes then if it is I run the code below: 

This gives me alert 2 msg then alert 3 msg with a value of 0 if attached or not, 

Any help would be very much appreciated, thank you 🙂 

function onSubmit() {
var myFieldValue = g_form.getValue('polygon_details_attached');

//Check if meant to have an attachment
if (myFieldValue == "Yes") {
  var cat_id = 'sysparm_item_guid'.value;
  var gr = new GlideRecord("sys_attachment");
  alert ("its yes 2");
  gr.addQuery("table_name", "sc_cart_item");
  gr.addQuery("table_sys_id", cat_id);
  gr.query();
  alert("its yes3 = " + gr.getRowCount());

  if (!gr.next()) {
     alert("You must attach a file to submit.");
    return false;
  }
}
}

[Nikkikobako]

Hi the attachment is only under 1 circumstance, so this option will not work for me, I did try it but it asked for it for every request, and I only want if they select a specific option

[AbhishekGardade · Accepted solution]

This may help:

Possible Ways for Making an Attachment Mandatory : Service Portal/Native UI

Please mark as Correct Answer and Helpful.
Thank You!
Abhishek Gardade

[Nikkikobako]

this worked

function onSubmit() {
var myFieldValue = g_form.getValue('polygon_details_attached');
//Check if meant to have an attachment
if (myFieldValue == "Yes") {
if(this.document.getElementsByClassName('get-attachment').length == 0) {
alert('You must add an attachment before submitting this request.');
return false;
}
}
}

with the isolate script not ticked thank you