Writing reusable JavaScript functions

Fool me once, shame on you; fool me twice, shame on me!

Whenever you see yourself copying and pasting code more than once, consider refactoring your code into reusable functions. In the first two recipes of this chapter, we built single-purpose functions with hardcoded values. We can refactor our code into a collection of reusable functions.

In this recipe, we will refactor our two functions into generic ones by parameterizing them.

Getting ready

As per the previous recipe, you will need an IDE and access to a Dynamics 365 instance with the System Customizer or higher security role.

How to do it...

1. Navigate to Settings | Solutions | Packt.
2. Click on Web Resources and double-click on packt_common.js.
3. Click on Text Edit and change the populateWithTodaysDate code to the following:

packtNs.common.populateWithTodaysDate =  function(attributeToMonitor, dateAttributeToChange) 
{ 
  if (Xrm.Page.getAttribute(attributeToMonitor).getValue() !== null && 
     Xrm...