A Client Script is a JavaScript code that runs on the client-side, typically in a user's web browser. It is triggered by specific client-side events, such as when a form is loaded, when a form is submitted, or when a field value is changed. Client Scripts allow you to enhance user interactions by executing custom logic in response to these events.

There are four main types of Client Scripts:

1. OnLoad: Executes when the form is loaded in the browser. It is commonly used to set default values, modify the form layout, or hide/show fields.

2. OnSubmit: Runs when the form is submitted. It is used to validate form data or perform additional actions before the form is saved.

3. OnCellEdit: Triggers when a cell in a record is edited (typically in list-type forms). It allows you to perform actions based on the changes made to the data in the cell.

4. OnChange: Activates when the value of a field changes. This script is useful for dynamically updating other fields, performing validation, or applying conditional logic based on the new value.

Yes, an OnChange Client Script is always triggered during form load. However, the script often includes a condition that prevents further execution of script if the form is in "loading" state. This is typically controlled by a variable like isLoading, which indicates whether the form is in the process of loading.

To execute the OnChange script during form load, you can modify the script to remove or adjust this check. Here's how you can achieve this:
1. Locate the condition that checks if the form is loading that is condition with isLoading variable.
2. Remove or modify this condition so that the OnChange logic is triggered regardless of the form's loading state.

Sample client script for reference:

There are few fields which are not part of current table, they are brought from another reference field table.

e.g. In below example, highlighted field is Caller Email which is brought from Caller reference that is from USER table.

So, to access value from such field, we can use below syntax in client script:
g_form.getValue("caller_id.email");

UI Policies are ideal for scenarios where you need to make fields mandatory, read-only, or conditionally hide/show fields based on certain conditions. They offer an easy way to enforce field behaviors without writing complex scripts.

Client Scripts, on the other hand, are more versatile and allow you to write advanced scripting logic. They are suitable for tasks like dynamically setting form field values based on complex conditions, retrieving server-side data on the client-side, or performing other custom client-side processing.

We can prevent form submission by using the "return false" statement in an "onSubmit" client script. This method is typically used to validate the form before allowing submission.

              
function onSubmit() {
    // Custom validation logic
    if (g_form.getValue('some_field') == '') {
        alert('Some field must be filled!');
        return false; // Prevent form submission
    }
    // If validation passes, the form will submit normally
    return true;
}

              
            

In client scripts, we can access the following key objects to interact with the form and user data:

1. g_form: This object is used to interact with form fields, retrieve or set field values, manipulate field visibility, read-only status, and other form-related properties.
e.g. g_form.setValue('field_name', 'new_value');

2. g_scratchpad: This object is used to store temporary data on the client side that can be passed from server-side scripts (like Business Rules or Script Includes) to the client-side. It is useful for sharing data between server and client without modifying the form fields.
e.g. g_scratchpad.someData = 'value from server-side script';

3. g_user: This object provides information about the currently logged-in user, such as their username, roles, and other user-related data. It's helpful for conditionally controlling the behavior of client scripts based on the user's identity or role.
e.g. var currentUser= g_user.getUsername();

1. Explain any complex client script that you have created for given requirement?

2. Did you learn anything interesting while working on client script which is not common or documented?

3. Did you ever face any issue/challenges while using GlideAjax call in client script?

4. If you used GlideAjax method to get server side data then why used GlideAjax, why not getReference or Display BR?

1. How to send more than one variable from server side script to client side while using GlideAjax?

2. Why we won't be able to stop form submission while validating form data via GlideAjax call?

3. Explain each step that needs to be done on script include side to use it for GlideAjax?