|  | Functions: call / apply / f() | | |
| | | Philippe Poulard |  |
|  Posted: Fri Sep 05, 2008 6:21 am Post subject: Functions: call / apply / f() |  |
| |  | |
Hi folks !
I have some code like this that passes an anonymous function:
foo.bar(p1, function(p2) {
alert(p2);
});
in foo.bar, i create a button with a listener; when it is executed, the
following code fails to run:
bar : function(somePara, someFunction) {
...
someButton.addListener("execute", function(e) {
someFunction(someData);
});
...
}
I google for some documentation and this version works well:
bar : function(somePara, someFunction) {
...
someButton.addListener("execute", function(e) {
someFunction.call(null, someData);
});
...
}
I don't understand the difference between f.apply(), f.call() and f()
and why the latter doesn't work
In fact, when using f("foo") the function is executed (I'm sure of that
when I insert alert("Hello")), but without its argument if in the body
of the anonymous function i use alert(p2) it fails
Please can you explain this behaviour ?
--
Cordialement,
///
(. .)
--------ooO--(_)--Ooo--------
| Philippe Poulard |
-----------------------------
LINK
Have the RefleX ! |
| |
| | | Martin Honnen | |
| | Posted: Fri Sep 05, 2008 8:40 am Post subject: Re: Functions: call / apply / f() | |
| | | |
Philippe Poulard wrote:
| Quote: | I have some code like this that passes an anonymous function:
foo.bar(p1, function(p2) {
alert(p2);
});
in foo.bar, i create a button with a listener; when it is executed, the
following code fails to run:
bar : function(somePara, someFunction) {
...
someButton.addListener("execute", function(e) {
someFunction(someData);
});
...
}
|
Do you get an error? Which one exactly?
| Quote: | I google for some documentation and this version works well:
bar : function(somePara, someFunction) {
...
someButton.addListener("execute", function(e) {
someFunction.call(null, someData);
});
...
}
I don't understand the difference between f.apply(), f.call() and f()
and why the latter doesn't work
In fact, when using f("foo") the function is executed (I'm sure of that
when I insert alert("Hello")), but without its argument if in the body
of the anonymous function i use alert(p2) it fails
Please can you explain this behaviour ?
|
So the alert dialog does not appear? Have you checked the error console
of the browser?
I don't see a reason why f() should fail but f.call() should execute.
--
Martin Honnen
http://JavaScript.FAQTs.com/ |
| |
| | | Philippe Poulard | |
| | Posted: Fri Sep 05, 2008 10:28 am Post subject: Re: Functions: call / apply / f() | |
| | | |
Martin Honnen a écrit :
| Quote: | Philippe Poulard wrote:
I have some code like this that passes an anonymous function:
foo.bar(p1, function(p2) {
alert(p2);
});
in foo.bar, i create a button with a listener; when it is executed, the
following code fails to run:
bar : function(somePara, someFunction) {
...
someButton.addListener("execute", function(e) {
someFunction(someData);
});
...
}
Do you get an error? Which one exactly?
|
No because it is trapped by the framework within which it is executed
(that doesn't log it correctly); but it fails because i don't get the
alert box (I'm sure the block is executed because if I insert
alert("Hello"); before alert(p2); I see the former but not the latter)
Therefore, it seems that a reference to p2 make all the stuff crashing
| Quote: |
I google for some documentation and this version works well:
bar : function(somePara, someFunction) {
...
someButton.addListener("execute", function(e) {
someFunction.call(null, someData);
});
...
}
I don't understand the difference between f.apply(), f.call() and f()
and why the latter doesn't work
In fact, when using f("foo") the function is executed (I'm sure of
that when I insert alert("Hello")), but without its argument if in the
body of the anonymous function i use alert(p2) it fails
Please can you explain this behaviour ?
So the alert dialog does not appear? Have you checked the error console
of the browser?
I don't see a reason why f() should fail but f.call() should execute.
|
ok, so it's not my fault 
since f.call() works, I have changed to it in my code
--
Cordialement,
///
(. .)
--------ooO--(_)--Ooo--------
| Philippe Poulard |
-----------------------------
LINK
Have the RefleX ! |
| |
|
|
