Yes I agree. I think the best we can do is to define Class.isSubclassOf
predicate, something like:
Class.isSubclassOf = function isSubclassOf(classA:Class, classB:Class):Boolean {
if (classA === Object) { return false; }
if (classA === classB) { return true; }
if ($as3) {
return
isSubclassOf(flash.utils.getDefinitionByName(flas.utils.getQualifiedSuperclassName(classA)),
classB);
} else {
return classA.prototype is classB;
}
}
I'm testing this now...
On 2010-01-18, at 08:55, Raju Bitter wrote:
> This might help to retrieve qualified class and superclass name:
> var sprite:Sprite = new Sprite();
> trace(getQualifiedClassName(sprite)); // "flash.display::Sprite"
> //or to retrieve the name of the super class, use:
> trace(getQualifiedSuperclassName(sprite)); //
> "flash.display::DisplayObjectContainer"
>
>
> On Jan 18, 2010, at 2:50 PM, P T Withington wrote:
>
>>
>> On 2010-01-18, at 04:34, Rami Ojares / AMG wrote:
>>
>>> Below is the debug output.
>>> At the bottom is the result of clicking one of the "<Pane>" objects in the
>>> debugger.
>>> So from that I draw the following conclusions.
>>>
>>> The argument c (the child) is an object with attributes
>>> - attrs, children (might be missing), class
>>>
>>> attrs seems to be an object (curly braces)
>>> children seems to be an array (brackets)
>>> class seems to be something special ( less-than, greater-than) I would
>>> assume this is class (sorry but I don't know exactly what is the
>>> distinction between class and object in javascript).
>>
>> I need to write up more about how the debugger represents objects.
>> Basically, it tries to print a literal representation that is isomorphic to
>> the actual object. Javascript is a prototype-based language, and we build
>> classes and instances on top of the prototyping mechanism. There is no
>> literal representation of an object that has a prototype different from
>> Object.prototype, so the debugger represents such objects in the format
>> <<"type"#"unique id"| "mnemonic name">>. It will also use this format if an
>> object that does have a literal representation is abbreviated due to being
>> longer than Debug.printLength, or deeper than Debug.printDepth, or contains
>> circular references. Finally, if you use the format "%#w", the debugger
>> will only use the literal representation if the literal representation will
>> be `==` to the actual object -- any other object will be represented using
>> the detailed <<>> format.
>>
>>> So far so good.
>>> The childClass seems to be always something of the form <...> (ie. class)
>>> Like it was supposed to.
>>>
>>> Then I execute the crucial line
>>> childClass.prototype is lz.Pane
>>>
>>> But it always returns false...damn.
>>
>> I think I see the problem. You must be using swf9/10? And in that runtime,
>> the test I described will not work. Hm. In fact, I'm not sure how you can
>> ask if one Class is a subclass of another Class in AS3. I'll have to
>> research that!
>
