Apple WebObjects 3.5 - Manual (Page 46)

Chapter 2 Enhancing Your Application
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The table should now look like this:
3. Save the Main component.
Creating the Guest Object
Earlier in this chapter, you created a Java class of type Guest and wrote a
constructor for it. You also added a variable of that class,
currentGuest , to the Main
component. However, adding a variable in this way doesn’t actually create a new
Guest object; you need to create one explicitly at some point in your code.
You’ll create the Guest object in the constructor method for your component.
This method is called when the component is first created; that is, the first time
the user accesses the component.
Note: In WebScript or Objective-C, you use a method called init for this purpose.
1. Choose View Source File from the pull-down menu at the bottom of the
window.
Project Builder becomes active and displays the code for Main.java . Notice
the following declaration that was added to your code when you added the
currentGuest variable:
protected Guest currentGuest;
2. Delete the declarations of guestName , email and comments , since you aren’t using
them anymore.
3. Add the constructor method inside the Main class definition:
Main() {
super();
currentGuest = new Guest();
}
The first statement calls the constructor of Main’s superclass (which is
next.wo.Component). The second statement allocates a new empty Guest
object and calls Guest’s constructor to initialize its instance variables.