Chapter 3. Server-Side Control

In the first few chapters, we've see how ServiceNow can hold your data. We've made a few tables, started to link it together, and collected it together in a new application. But simply storing data isn't going to make an award winning application.

So it's wonderful that ServiceNow also gives you great control over your data: you can check it, change it, or censor it using a variety of mechanisms. As we progress through this chapter, we'll see how information can be validated by a data policy, emailed out with notifications, or secured by an access control rule.

All of these are good options on their own, but ServiceNow also gives you complete control through code. You can write scripts to control almost any action you can think of. So the main focus of this chapter is to give you a good understanding of how server-side scripting in ServiceNow works. Here's how this chapter is structured:

• We will start by diving into server-side JavaScript, including how to access the database. Scripts using GlideRecord are probably the most common in ServiceNow.
• Business Rules are the starting point for logic in ServiceNow. We explore the different flavors by running through a variety of scenarios.
• Script Includes provide a place for your code libraries. We will look at how you can define classes, extend them, and run them.
• To really understand JavaScript in ServiceNow, we will explore the engine that powers the platform.
• Finally, data policies and advanced reference qualifiers show other ways of controlling data access and logic.