431674 - Java field private access doesn't work well with Java Bean access

Status: RESOLVED FIXED

(Rhino Graveyard :: Core, defect)

Description

[Norris Boyd]

Automagic property access -- and when it's a bit too magical

Let's say you have a Java class with a standard getFoo/setFoo pair of methods. Rhino lets automatically unmangles the names and let you write code like this:

var aFooHolder = new JavAFooHolder();
aFooHolder.foo = 'kung';
print(aFooHolder.foo); // prints 'kung'

Magical! But wait, theres (unfortunately) more. Under some circumstances (what are these?) Rhino will also see private class variables. Even more unfortuantely, it seems to prefer the private member variables to the demangled property-access methods. This can bite you like a black mamba on a sunless Serengetti night. Let's say that the FooHolder?'s setFoo method has Important Side Effects:

var aFooHolder = new JavAFooHolder();
aFooHolder.foo = 'kung'; // should also close the Exhaust Port leading to the reactor core 
print(aFooHolder.foo); // prints 'kung', because the private member variable is set correctly


assertFalse(ExhaustPort.isOpen); // Augh! We're wide open to Rebel attack!

This can be maddening, because the member variable appears to have been 'set' but it was really inserted with a needle. Beware!

Comment 1

[Norris Boyd]

Fixed: 

Checking in src/org/mozilla/javascript/JavaMembers.java;
/cvsroot/mozilla/js/rhino/src/org/mozilla/javascript/JavaMembers.java,v  <--  JavaMembers.java
new revision: 1.77; previous revision: 1.76
done
Checking in testsrc/org/mozilla/javascript/tests/JavaAcessibilityTest.java;
/cvsroot/mozilla/js/rhino/testsrc/org/mozilla/javascript/tests/JavaAcessibilityTest.java,v  <--  JavaAcessibilityTest.java
new revision: 1.4; previous revision: 1.3
done
Checking in testsrc/org/mozilla/javascript/tests/PrivateAccessClass.java;
/cvsroot/mozilla/js/rhino/testsrc/org/mozilla/javascript/tests/PrivateAccessClass.java,v  <--  PrivateAccessClass.java
new revision: 1.4; previous revision: 1.3
done