Application Package (Public vs Protected vs Private) Methods Part 1

Today, we will check the difference between public, protected and private for Application Packages.

First, let's check this sample Application Package.

class Person
   method Person();
   method SayBarbecue();
   property string Property1;
protected
   method SayHello();
   property string Property2;
private
   method SayGoodbye();
   instance string &Property3;
end-class;

method Person
end-method;

method SayBarbecue
   MessageBox(0, "", 0, 0, "Barbecue!");
end-method;

method SayHello
   MessageBox(0, "", 0, 0, "Hello!");
end-method;

method SayGoodbye
   MessageBox(0, "", 0, 0, "Goodbye!");
end-method;

We have 3 methods.

• public method: SayBarbecue()
• protected method: SayHello()
• private method: SayGoodbye()

What will happen if we use these methods outside the application class?
The following code has been placed on a FieldChange event.

import TEST_APP_PKG:*;

Local TEST_APP_PKG:Person &Lon = create TEST_APP_PKG:Person();

&Lon.SayBarbecue();

/* Cannot be called because these methods are protected or private */
rem &Lon.SayHello();
rem &Lon.SayGoodbye();

SayBarbecue() method can be freely used.
But SayHello() and SayGoodbye() methods will error at compile time.
This is because protected and private methods can only be used within the application class.