JavaFX Primer - JavaFX: Developing Rich Internet Applications - page 63

not be invoked during object creation. Now when we assign a value to status ,
the state changes to initialized , so commenceTest is now invoked. Please note
that if we had assigned a default value to status , even if that value is 0, then
status immediately is set to initialized . The following example demon-
strates this.
public class Test {
public var status: Number = 0 on replace {
// will be initialized immediately.
if( isInitialized (status)) {
commenceTest(status);
}
}
The last built-in function is isSameObject() . isSameObject() indicates if the
two arguments actually are the same instance. This is opposed to the == operator.
In JavaFX, the == operator determines whether two objects are considered equal,
but that does not mean they are the same instance. The == operator is similar to
the Java function isEquals() , whereas JavaFX isSameObject is similar to the
Java == operator. A little confusing if your background is Java!
The built-in variables are __DIR__ and __FILE__ . __FILE__ holds the resource
URL string for the containing JavaFX class. __DIR__ holds the resource URL
string for directory that contains the current class. For example,
println("DIR = { __DIR__ }");
println("FILE = { __FILE__ }");
// to locate an image
var image = Image { url: "{ __DIR__ }images/foo.jpeg" };
The following examples show the output from a directory based classpath versus
using a JAR-based class path.
Using a Jar file in classpath
$javafx -cp Misc.jar misc.Test
DIR = jar:file:/export/home/jclarke/Documents/
Book/FX/code/Chapter3/Misc/dist/Misc.jar!/misc/
FILE = jar:file:/export/home/jclarke/Documents/
Book/FX/code/Chapter3/Misc/dist/Misc.jar!/misc/Test.class
continues