Another riddle for Tucker:
I can call:
_root.Debug.write("%s: %d - %d", arguments.callee, n1, n2);
But I cannot call:
_root.Debug.write("%s: %d - %d (%s)", arguments.callee, n1, n2,
Debug);//or i.e. global, canvas etc. breaks, too
So, in which context does get Array#sort(..) called?
It _is_ getting called. For some reason, your Debug.write is failing
to send any output:
lzx> Debug.trace(canvas, 'laszloMethod')
lzx> [1,2,3].sort(canvas.laszloMethod)
TRACE: [394491.00] laszloMethod.apply(?undefined?, [1, 2])
laszloMethod( 1 , 2 )
TRACE: [394501.00] laszloMethod -> 0
TRACE: [394505.00] laszloMethod.apply(?undefined?, [1, 3])
laszloMethod( 1 , 3 )
TRACE: [394512.00] laszloMethod -> 0
TRACE: [394516.00] laszloMethod.apply(?undefined?, [1, 2])
laszloMethod( 1 , 2 )
TRACE: [394523.00] laszloMethod -> 0
TRACE: [394527.00] laszloMethod.apply(?undefined?, [2, 3])
laszloMethod( 2 , 3 )
TRACE: [394536.00] laszloMethod -> 0
?Array(3)#15| [1, 2, 3]?
lzx>
Oh, hah-hah. I see why. Because laslzoMethod is a method, it expects
a 'this' argument, and our compiler inserts an implicit `with (this)`
around your method body, but you are calling it as a function, and
`this` is undefined in that case (see the trace output above). So
your code is turning into `with (undefined)` and I bet that causes the
global reference to Debug to fail. Amusingly, tracing the method
makes the debug output work. I can't really explain that.
If you were to make a closure to call your method, it should work:
lzx> Debug.untrace(canvas, 'laszloMethod')
lzx> [1,2,3].sort(function (a, b) { return canvas.laszloMethod(a, b) })
laszloMethod( 1 , 2 )
laszloMethod( 1 , 3 )
laszloMethod( 1 , 2 )
laszloMethod( 2 , 3 )
?Array(3)#57| [1, 2, 3]?
lzx>
On 2008-01-09, at 14:28 EST, Pablo Kang wrote:
Btw, I know that I can call a laszloMethod from a Javascript
function like:
<method name="javascriptFunction" args="n1,n2">
return canvas.laszloMethod(n1,n2);
</method>
What I want to know is why it is I can't pass in the the
laszloMethod directly.
Thanks,
pablo
On Wed, 9 Jan 2008, Pablo Kang wrote:
Anyone know why passing in a function defined with an LZX method
tag into Array.sort doesn't work? Here's a test case:
<canvas debug="true">
<method name="laszloMethod" args="n1,n2">
Debug.write('laszloMethod(', n1, ',', n2, ')');
return 0;
</method>
<script>
function javascriptFunction(n1,n2) {
Debug.write('javascriptFunction(', n1, ',', n2 ,')');
return 0;
}
</script>
<handler name="oninit">
var arr = [ 1,2,3 ];
Debug.write('-- Javascript Function --');
arr.sort( javascriptFunction );
Debug.write('-- Laszlo Method --------');
arr.sort( canvas.laszloMethod );
</handler>
</canvas>
pablo
