Ok. I'll use that pattern.
I guess we should think about adding getters and setters to our JS.
All the runtimes actually support them, we just have to make the
appropriate translation. Then you would be able to say:
function get instance () { return singleton; }
But, if you can initialize a static var to an instance of the class,
can you just say:
public static const instance = new SingletonClass;
? Then you would not need a getter or an accessor to protect the
instance...
I think our JS1 translator will choke because it will try to evaluate
the constructor before it is defined. (The translator would have to
be amended to move static initializers to the class body.)
On 2008-03-22, at 18:09 EDT, Donald Anderson wrote:
Not approved.
1) Tried this in SWF9 doing some hand coding, and can't get around
this compile error:
/private/tmp/lzswf9/lzgen64824/SingletonClass.as(6): col: 37 Error:
Return value must be undefined.
return SingletonClass.singleton;
^
So it does appear that 'new' is behaving like C++ or Java - the
object is
created, and the value of the reference is determined before the
constructor is called.
Maybe use a pattern like this:
class SingletonClass {
private static var singleton:SingletonClass = new SingletonClass();
public static function instance():SingletonClass { return
singleton; }
function SingletonClass() { if (singleton != null) throw "Use
SingletonClass.instance() instead of new"}
}
usage: var s = SingletonClass.instance();
I added the throw because constructors cannot be marked private (at
least flex gives an error).
