Salesforce Platform Developer I Certification Guide

Controller extensions

The name says it all. This is an Apex class that extends the functionality of your standard controller. You can insert a new actor into a movie with the standard controller in a Visualforce page, but you need to verify whether this person already exists in our database or not. If the person already exists, you link this existing person to the movie; if not, you need to create them. Maybe you just want to select and display some more information about the related objects. There are many scenarios where you can use an extension on a standard controller:

• Show a Visualforce page when you click on a button. You need to define the standard object controller in your page in the way your button was configured.
• If you want to ...