change GlideAjax method from GetXML() to GetXMLWait()

[sureshp89882164]

Scenario is: A 'Pop-Up' message will appear on-screen when any end-user attempts to re-assign (more than one time) already assigned incident to the Technical Service Desk (TSD).

Which one is the best one either using with GetXML() OR GetXMLWait()

Currently using with GlideAjax method GetXML(), what changes i have to do if I change from GetXML() to GetXMLWait() on below code:

function onChange(control, oldValue, newValue, isLoading, isTemplate) {

   if (isLoading || newValue === '') {

      return;

   }

 var ga = new GlideAjax('assignmentCountincident');

    ga.addParam('sysparm_name', 'getIncidentCount');

    ga.addParam('sysparm_inc_sysid', g_form.getUniqueValue());

    ga.getXML(responseParse);

function responseParse(response){

    var answer = response.responseXML.documentElement.getAttribute("answer");

    if ((answer>=1) && (newValue == 'f1bb47cadb2e83008449f6e9bf96190f')){

alert('Incidents are not to be reassigned back to TSD for resolution, customer call back and/or further team re-assignment. );

}

}

}

script include: assignmentCountincident

[debendudas]

Hi @sureshp89882164 ,

For a client-side onChange script that displays an alert, using getXMLWait() is generally not the recommended best practice. The current getXML() approach, which is asynchronous, is better for user experience. 

getXML() vs. getXMLWait() for your scenario:

1. getXML() (Asynchronous)

• How it works: The script sends a request to the server and continues processing without waiting for the response. When the response is received, the callback function (responseParse in your code) is executed.
• Pros: The UI remains responsive. The user can continue to interact with the form while the server-side lookup is happening.
• Cons: Since the script doesn't pause, the alert will pop up after the user has already changed the assignment group. If the user clicks "Save" very quickly, the alert might appear too late to prevent the re-assignment. 

2. getXMLWait() (Synchronous)

• How it works: The script pauses and freezes the user interface until a response is received from the server.
• Pros: You are guaranteed to get the server's response before the rest of the client-side code continues. This means the alert will fire immediately after the value change, and you could add logic to prevent form submission.
• Cons: This is considered bad practice because it freezes the UI, creating a poor user experience, especially on slow connections. It is generally discouraged by ServiceNow. 

If this solution helps you then, mark it as accepted solution ‌‌✔️ and give thumbs up 👍! 

[debendudas]

Here is the SN documentation you can check out for the code: https://www.servicenow.com/docs/csh?topicname=c_GlideAjaxAPI.html&version=latest