ServiceNow Scripting Best Practices | Things to Remember

ServiceNow scripting is a powerful tool that can help you automate processes and improve the functionality of your instance. Here are some best practices for scripting in ServiceNow.

ServiceNow Scripting Best Practices:

1.  Use comments to document your code: Comments are essential for documenting your code and making it easier to understand for other developers. Use comments to explain what each block of code does and why it's necessary.

For e.g.

/*

     * addGlideListElement - add a sys_id to a specified glide list field

     *

     * @param grField - field element to add a value (e.g. current.assigned_tot)

     * @param id - sys_id to add (if it doesn't already exist)

     * @return - new list values

     *

*/

2.  Use meaningful variable and functions names: Use descriptive variable and functions names that make it easy to understand what the variable is used for. Avoid using generic names like "x" or "y" that don't convey any meaning.

For e.g.

function deleteExistEntry(glideRec, defaultAnswer, stateValue) {

var student= 0;

    if (stateValue == 13)

        glideRec.deleteRecord();

    else

        student= = defaultAnswer;

    return student;

}

3. Write Simple Statements so that it will be understandable for less experience developers too. 

For e.g. 

var incidentRecord = (x == y) ? a : b;  // let says experience developer writes this syntax

But easiest understandable syntax for beginner is:

var incidentRecord;

if(x==y){

incidentRecord = a; 

}

else{

incidentRecord = b;

}

4.  Use error handling to improve reliability: Add error handling to your code to ensure that unexpected errors don't cause your script to fail. Use try/catch blocks to handle exceptions and log error messages to help diagnose and resolve issues.

5.  Use functions to break up complex code: Break up complex code into smaller, reusable functions that are easier to test and maintain. Use meaningful function names that describe what the function does.

6.  Use the GlideRecord API for database operations: Use the GlideRecord API to interact with the ServiceNow database. This API provides a safe and efficient way to query, insert, update, and delete records.

7.  Use the gs.log() method for logging: Use the gs.log() method to log messages to the ServiceNow system log. This helps you diagnose and troubleshoot issues, and it's also useful for auditing purposes.

8.  Use variable to store function result.

For e.g.

var loggedInUser = gs.getUserID();

var isOwner = (loggedInUser == current.assigned_to);  // return true or false

9.  Below thing should be taken care while interacting with the database:

        a)  Avoid Complex GlideRecord Queries

        b)  Use GlideAggregate for Simple Record Counting: For e.g. Total number of incident per category or groupby category.

function countIncidentPerCategory() {

     var inc = new GlideAggregate('incident');

     inc.addAggregate('COUNT','category')

     inc.query();

     while (inc.next()){

gs.info(inc.getValue('category')+ ' --- '+inc.getAggregate('COUNT','category'));

      }

}

        c)  Avoid Complex Queries on Large Data Sets

        d)  Let the Database Do the Work

10. Use self execution function. For e.g.

(function givefunctionName() {

  //Write the script you want to run

})(); //Note the parenthesis indicating this function should run.

11.  Test your code thoroughly: Always test your code thoroughly before deploying it to a production environment. Use automated testing tools (ATF's, Selenium etc.) to ensure that your code is reliable and performs as expected.

By following these best practices, you can write efficient, reliable, and maintainable scripts that help you automate processes and improve the functionality of your ServiceNow instance. Please let us know your feedback, questions and suggestions related to ServiceNow scripting best practices below in comment section.