Catalog CS Not Updating Field onChange

[appstorm]

I am attempting to use an onChange Client Script to populate the C# (employee_number) field on a form when the student_name field changes.  Both student_name and employee_number are reference fields that point to the sys_user table from the form, while employee_number on the sys_user table is a string.  I keep getting a no student found with sys_id error when the student_name field changes on the form.  However, I can verify the sys_id returns the correct user when I query the sys_user table.  I have also confirmed the employee_number for said student is not empty.  So, I am not sure why it's showing as invalid on the form.

function onChange(control, oldValue, newValue, isLoading) {
    // Skip if the form is still loading or if no student is selected
    if (isLoading || newValue == '') {
        return;
    }

    // Ensure the value is a valid Sys ID
    if (!newValue || typeof newValue !== 'string') {
        g_form.addErrorMessage('No student selected or invalid value.');
        return;
    }

    // Log the value passed to check if it's a valid Sys ID
    console.log('newValue from student_name field (Sys ID): ' + newValue);

    // Create a GlideRecord object to query the sys_user table for the selected student
    var userGR = new GlideRecord('sys_user');

    // Query sys_user table by the Sys ID of the student (newValue is the Sys ID from student_name)
    if (userGR.get(newValue)) {  // Use the Sys ID directly
        var employeeSysId = userGR.sys_id;  // Sys ID of the user from sys_user table

        // Check if employeeSysId exists (this will always be true if the Sys ID is valid)
        if (employeeSysId) {
            // Set the employee_number field with the Sys ID from sys_user
            g_form.setValue('employee_number', employeeSysId);
            console.log('Employee Sys ID found: ' + employeeSysId);
        } else {
            // Clear the field if no employee found (this is mostly redundant, as employeeSysId should always exist)
            g_form.setValue('employee_number', '');
            console.log('No employee found for this student.');
        }
    } else {
        // Log the failure to get the record from sys_user
        console.log('Error: No student found for Sys ID: ' + newValue);
        g_form.addErrorMessage('No student found for the selected Sys ID: ' + newValue);
    }
}

[Vaibhav_Nikam]

Hello @appstorm ,
Hope you are doing well!
To achieve the above requirement you need to do it by using client script + script Include using glideAjax API.

Refer it: Script Include and Client Script using glideajax 

[appstorm]

Thanks for the reply!  I added a SI to the revised Client Script, but am still getting an error  "Unhandled exception in GlideAjax. Cannot read properties of null (reading 'responseXML')" even when hardcoding a sys_id in the script include.

CS:

function onChange(control, oldValue, newValue, isLoading) {
    // Skip if the form is still loading or if no student is selected
    if (isLoading || newValue == '') {
        return;
    }

    // Log the selected Sys ID for debugging
    console.log('Selected Sys ID from student_name field: ' + newValue);

    // Initialize GlideAjax request to call the Script Include
    var ga = new GlideAjax('GetStudentEmployeeNumber');
    ga.addParam('sys_id', newValue);  // Pass the Sys ID of the student

    // Make the GlideAjax request and handle the response
    ga.getXMLAnswer(function(response) {
        try {
            // Parse the response as JSON
            var jsonResponse = JSON.parse(response);
            
            // Check for error in response
            if (jsonResponse.error) {
                console.log('Error from server: ' + jsonResponse.error);
                g_form.addErrorMessage('Error: ' + jsonResponse.error); // Display error message to user
            } else {
                // Extract employee_number from the JSON response
                var employeeNumber = jsonResponse.employee_number;
                console.log('Employee Number from JSON: ' + employeeNumber);
                g_form.setValue('employee_number', employeeNumber); // Update the field with the employee number
            }
        } catch (e) {
            console.log('Error processing response: ', e); // Log any parsing errors
            g_form.addErrorMessage('Error processing response.');
        }
    });
}

SI

var GetStudentEmployeeNumber = Class.create();
GetStudentEmployeeNumber.prototype = Object.extendsObject(AbstractAjaxProcessor, {
    
    // This function is the client callable method
    getEmployeeNumber: function() {
        var sysId = this.getParameter('sys_id'); // Get sys_id from GlideAjax request
        var userRecord = new GlideRecord('sys_user'); // Query the sys_user table
        
        if (userRecord.get(sysId)) {
            // Return employee number as a JSON response
            var employeeNumber = userRecord.getValue('employee_number');
            return new JSON().encode({
                employee_number: employeeNumber
            });
        } else {
            // If the user record isn't found, return an error in JSON format
            return new JSON().encode({
                error: 'User not found'
            });
        }
    }
});

[dgarad]

@appstorm 

Change to code as below.

CS:
ga.addParam('sysparm_sys_id', newValue);


SI:

var sysId = this.getParameter('sysparm_sys_id');