A problem that was discovered with the state properties mechanism and its support for ad hoc registration of properties has been fixed.
Refactoring of the state properties mechanism a while back introduced a subtle but undesirable behavior change in the registering of ad hoc properties. This problem has been fixed and unit tests have been written to ensure that the new behavior is protected from accidental breakage going forward. According to the new behavior, when a state property is registered in an ad hoc fashion by setting a value for that property on a class, then that value becomes the initial value for that state property. On the other hand, if a state property is registered in an ad hoc fashion by setting a value for that property on an instance, then the initial value for that property is undefined, so that new instances of the class that are created do not get the instance-specific value for the instance that prompted the property registration.
EXAMPLE
var MyClass = Uize.subclass ();
/*** ad hoc registration by setting value on class ***/
MyClass.set ({foo:'bar'});
var myInstance = new MyClass;
alert (myInstance.get ('foo')); // alerts the text "bar"
/*** ad hoc registration by setting value on instance ***/
myInstance.set ({hello: 'world'});
var
myOtherInstance = new MyClass,
allPropertiesOfMyOtherInstance = myOtherInstance.get ()
;
alert ('hello' in allPropertiesOfMyOtherInstance) // alerts the text "true"
alert (allPropertiesOfMyOtherInstance.hello) // alerts the text "undefined"
In the above example, after we create the class MyClass, we register the state property foo in an ad hoc fashion by setting a value for it on the class. This has the effect of both registering the property and setting its initial value for all instances of the class that are created going forward. So, when we alert the value of the expression myInstance.get ('foo'), we see the text "bar" displayed.
However, when we then register the property hello in an ad hoc fashion by setting a value for it on the instance myInstance, and we then create a new instance myOtherInstance of MyClass, we see that the new instance does have the state property hello but that its value is undefined. The get instance method returns an object containing the values of all the state properties when it is called with no arguments, as it was in this example.