Book Image

Mastering ServiceNow Scripting

By : Andrew Kindred
Book Image

Mastering ServiceNow Scripting

By: Andrew Kindred

Overview of this book

Industry giants like RedHat and NetApp have adopted ServiceNow for their operational needs, and it is evolving as the number one platform choice for IT Service management. ServiceNow provides their clients with an add-on when it comes to baseline instances, where scripting can be used to customize and improve the performance of instances. It also provides inbuilt JavaScript API for scripting and improving your JavaScript instance. This book will initially cover the basics of ServiceNow scripting and the appropriate time to script in a ServiceNow environment. Then, we dig deeper into client-side and server-side scripting using JavaScipt API. We will also cover advance concepts like on-demand functions, script actions, and best practices. Mastering ServiceNow Scripting acts as an end-to-end guide for writing, testing, and debugging scripts of ServiceNow. We cover update sets for moving customizations between ServiceNow instances, jelly scripts for making custom pages, and best practices for all types of script in ServiceNow. By the end of this book, you will have hands-on experience in scripting ServiceNow using inbuilt JavaScript API.
Table of Contents (18 chapters)
Title Page
Packt Upsell
Contributors
Preface
Index

Client script best practices


As we have seen, client scripts run on the client side and so only have access to data that has been sent to the client from the server. The main goal we have when writing client-side scripts is to minimize the amount of script we write and the calls to the server we make.

The reason we keep client scripting to a minimum is that these scripts run in front of the user and therefore directly effect loading times. We want to keep loading times to a minimum and, therefore, client scripting to a minimum also.

When writing a new client script, it is worth considering whether the script could be run on the server side instead, and if so, then this is usually considered a best practice.

Let's have a look at one of the most common bad practices in client scripting. Take the following script, for example:

function onLoad() {
  var user = new GlideRecord('sys_user');
  user.get(g_form.getValue('caller_id'));
  g_form.showFieldMsg('caller_id', 'Active: ' + user.active);

}

This...