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

System performance best practices

There are a number of attributes that make up the perceived performance of an instance. These can be greatly effected by badly coded scripts or a large number of them that are not required.

One of the most common ways scripting can cause perceived performance delays is when an excess of client scripts are used when a form opens. This causes a big delay in browser rendering and parsing, which is very apparent to the user. As we have mentioned before, a best practice in this scenario is to limit the amount of client scripts created only to those essential, and to ensure that server calls are kept to a minimum.

If information is needed for an onLoad client script, then consider a display business rule instead of calling the server from a client script. 

Using this method, we can obtain the information we need from the server from the display business rule before displaying a form. Then, we run client-side code in a client script that will be able to use the information...