a tough question

[Mr Shore]

hi all
what I want to do is as below
start a function
halt on,
until some event occurs(maybe user click)
and then return some value accordingly.
Or is it possible to do this stuff?

[Joost Diepenmaat]

Re: a tough question

Mr Shore <shore.cloud@gm ail.comwrites:

hi all
what I want to do is as below
start a function
halt on,
until some event occurs(maybe user click)
and then return some value accordingly.
Or is it possible to do this stuff?

No, and you don't want to do that anyway. Just do whatever it is you
need to do from the onclick handler. Don't fight the event model.


--
Joost Diepenmaat | blog: http://joost.zeekat.nl/ | work: http://zeekat.nl/

[Mr Shore]

Re: a tough question

On Apr 14, 2:07 am, Joost Diepenmaat <jo...@zeekat.n lwrote:

Mr Shore <shore.cl...@gm ail.comwrites:

hi all
what I want to do is as below
start a function
halt on,
until some event occurs(maybe user click)
and then return some value accordingly.
Or is it possible to do this stuff?

>
No, and you don't want to do that anyway. Just do whatever it is you
need to do from the onclick handler. Don't fight the event model.
>
--
Joost Diepenmaat | blog:http://joost.zeekat.nl/| work:http://zeekat.nl/

so what do you think of the prompt function?

[Joost Diepenmaat]

Re: a tough question

Mr Shore <shore.cloud@gm ail.comwrites:

>No, and you don't want to do that anyway. Just do whatever it is you
>need to do from the onclick handler. Don't fight the event model.

>
so what do you think of the prompt function?

It's a hack; it prevents the user from doing anything else while the
prompt is active, and there is no way to replicate the behaviour with
user-written javascript. The "best" you can do is to disable everything
else on the page (using some kind of overlay, for instance). That
/still/ won't give you the "call function and use return value"
mechanism, and there is no reason you need that - the event model is
much more flexible.

You just need

show_my_prompt( data,function(v alue) {
// do stuff with value
});

instead of

var value = prompt(data);
// do stuff with value.

--
Joost Diepenmaat | blog: http://joost.zeekat.nl/ | work: http://zeekat.nl/

[Mr Shore]

Re: a tough question

On Apr 14, 2:37 am, Joost Diepenmaat <jo...@zeekat.n lwrote:

Mr Shore <shore.cl...@gm ail.comwrites:

No, and you don't want to do that anyway. Just do whatever it is you
need to do from the onclick handler. Don't fight the event model.

>

so what do you think of the prompt function?

>
It's a hack; it prevents the user from doing anything else while the
prompt is active, and there is no way to replicate the behaviour with
user-written javascript. The "best" you can do is to disable everything
else on the page (using some kind of overlay, for instance). That
/still/ won't give you the "call function and use return value"
mechanism, and there is no reason you need that - the event model is
much more flexible.
>
You just need
>
show_my_prompt( data,function(v alue) {
// do stuff with value
>
});
>
instead of
>
var value = prompt(data);
// do stuff with value.
>
--
Joost Diepenmaat | blog:http://joost.zeekat.nl/| work:http://zeekat.nl/

ok,seems i have to give up that idea
thanks for the quick reply

[Mr Shore]

Re: a tough question

On Apr 14, 2:37 am, Joost Diepenmaat <jo...@zeekat.n lwrote:

Mr Shore <shore.cl...@gm ail.comwrites:

No, and you don't want to do that anyway. Just do whatever it is you
need to do from the onclick handler. Don't fight the event model.

>

so what do you think of the prompt function?

>
It's a hack; it prevents the user from doing anything else while the
prompt is active, and there is no way to replicate the behaviour with
user-written javascript. The "best" you can do is to disable everything
else on the page (using some kind of overlay, for instance). That
/still/ won't give you the "call function and use return value"
mechanism, and there is no reason you need that - the event model is
much more flexible.
>
You just need
>
show_my_prompt( data,function(v alue) {
// do stuff with value
>
});
>
instead of
>
var value = prompt(data);
// do stuff with value.
>
--
Joost Diepenmaat | blog:http://joost.zeekat.nl/| work:http://zeekat.nl/

still a question
how to pass variable parameters in js?
function t(a,b){
alert(b);
}

t(b="hi");
which i meant to set second parameter of function t as "hi" but failed

[Joost Diepenmaat]

Re: a tough question

Mr Shore <shore.cloud@gm ail.comwrites:

still a question
how to pass variable parameters in js?
function t(a,b){
alert(b);
}
>
t(b="hi");
which i meant to set second parameter of function t as "hi" but failed

Javascript only does positional parameters. Just do

t(undefined,"hi ");

or whatever you want to indicate "this parameter is useless" for the
first parameter. A possible downside to using undefined is that
undefined is a variable, and so can be set to a value that isn't
undefined. Anyone actually setting undefined to some defined value
should of course have their computer taken away.

See also: <http://developer.mozilla.org/en/docs/
Core_JavaScript _1.5_Reference: Functions:argum ents>

--
Joost Diepenmaat | blog: http://joost.zeekat.nl/ | work: http://zeekat.nl/

[VK]

Re: a tough question

On Apr 13, 11:10 pm, Joost Diepenmaat <jo...@zeekat.n lwrote:

Anyone actually setting undefined to some defined value
should of course have their computer taken away.

Thank you, bro! :-) :-|

[Mr Shore]

Re: a tough question

On Apr 14, 3:10 am, Joost Diepenmaat <jo...@zeekat.n lwrote:

Mr Shore <shore.cl...@gm ail.comwrites:

still a question
how to pass variable parameters in js?
function t(a,b){
alert(b);
}

>

t(b="hi");
which i meant to set second parameter of function t as "hi" but failed

>
Javascript only does positional parameters. Just do
>
t(undefined,"hi ");
>
or whatever you want to indicate "this parameter is useless" for the
first parameter. A possible downside to using undefined is that
undefined is a variable, and so can be set to a value that isn't
undefined. Anyone actually setting undefined to some defined value
should of course have their computer taken away.
>
See also: <http://developer.mozilla.org/en/docs/
Core_JavaScript _1.5_Reference: Functions:argum ents>
>
--
Joost Diepenmaat | blog:http://joost.zeekat.nl/| work:http://zeekat.nl/

thanks a lot
finally i tried your version,
which passed the function string then eval

[Joost Diepenmaat]

Re: a tough question

Mr Shore <shore.cloud@gm ail.comwrites:

On Apr 14, 3:10 am, Joost Diepenmaat <jo...@zeekat.n lwrote:
thanks a lot
finally i tried your version,
which passed the function string then eval

That's not what my version was intended to do. Javascript has proper
function objects, meaning you can pass functions around and call them
without the error prone and slow use of eval().

--
Joost Diepenmaat | blog: http://joost.zeekat.nl/ | work: http://zeekat.nl/

[Mr Shore]

Re: a tough question

On Apr 14, 5:25 am, Joost Diepenmaat <jo...@zeekat.n lwrote:

Mr Shore <shore.cl...@gm ail.comwrites:

On Apr 14, 3:10 am, Joost Diepenmaat <jo...@zeekat.n lwrote:
thanks a lot
finally i tried your version,
which passed the function string then eval

>
That's not what my version was intended to do. Javascript has proper
function objects, meaning you can pass functions around and call them
without the error prone and slow use of eval().
>
--
Joost Diepenmaat | blog:http://joost.zeekat.nl/| work:http://zeekat.nl/

but I don't know how to pass an executing function directly?

[Joost Diepenmaat]

Re: a tough question

Mr Shore <shore.cloud@gm ail.comwrites:

but I don't know how to pass an executing function directly?

I really hope that one day there will be a seriously good book about
javascript. Anyway:

function call_me_back(fu n) {
var value = 42;
fun(value);
}

call_me_back(fu nction(value) {
alert(value);
});

function cb(v) {
alert("V: "+v);
}

call_me_back(cb );


--
Joost Diepenmaat | blog: http://joost.zeekat.nl/ | work: http://zeekat.nl/

[Mr Shore]

Re: a tough question

On Apr 14, 5:32 am, Joost Diepenmaat <jo...@zeekat.n lwrote:

Mr Shore <shore.cl...@gm ail.comwrites:

but I don't know how to pass an executing function directly?

>
I really hope that one day there will be a seriously good book about
javascript. Anyway:
>
function call_me_back(fu n) {
var value = 42;
fun(value);
>
}
>
call_me_back(fu nction(value) {
alert(value);
>
});
>
function cb(v) {
alert("V: "+v);
>
}
>
call_me_back(cb );
>
--
Joost Diepenmaat | blog:http://joost.zeekat.nl/| work:http://zeekat.nl/

got it!
thanks a lot:)

[Mr Shore]

Re: a tough question

On Apr 14, 5:42 am, Mr Shore <shore.cl...@gm ail.comwrote:

On Apr 14, 5:32 am, Joost Diepenmaat <jo...@zeekat.n lwrote:
>

Mr Shore <shore.cl...@gm ail.comwrites:

but I don't know how to pass an executing function directly?

>

I really hope that one day there will be a seriously good book about
javascript. Anyway:

>

function call_me_back(fu n) {
var value = 42;
fun(value);

>

}

>

call_me_back(fu nction(value) {
alert(value);

>

});

>

function cb(v) {
alert("V: "+v);

>

}

>

call_me_back(cb );

>

--
Joost Diepenmaat | blog:http://joost.zeekat.nl/|work:http://zeekat.nl/

>
got it!
thanks a lot:)

but now i think maybe i'll stick to the error prone though eval
version
because otherwise it'll be quite hard for me to make it work in all
occasions,eg. the variable num of parameters and so on
error prone or general
i choose the later

[slebetman]

Re: a tough question

On Apr 14, 5:51 am, Mr Shore <shore.cl...@gm ail.comwrote:

On Apr 14, 5:42 am, Mr Shore <shore.cl...@gm ail.comwrote:
>
>
>

On Apr 14, 5:32 am, Joost Diepenmaat <jo...@zeekat.n lwrote:

>

Mr Shore <shore.cl...@gm ail.comwrites:
but I don't know how to pass an executing function directly?

>

I really hope that one day there will be a seriously good book about
javascript. Anyway:

>

function call_me_back(fu n) {
var value = 42;
fun(value);

>

}

>

call_me_back(fu nction(value) {
alert(value);

>

});

>

function cb(v) {
alert("V: "+v);

>

}

>

call_me_back(cb );

>

--
Joost Diepenmaat | blog:http://joost.zeekat.nl/|work:http://zeekat.nl/

>

got it!
thanks a lot:)

>
but now i think maybe i'll stick to the error prone though eval
version
because otherwise it'll be quite hard for me to make it work in all
occasions,eg. the variable num of parameters and so on
error prone or general
i choose the later

For variable numbers of parameters and named parameters the most
"natural" way I've found is to write functions that accept ONE
variable which is an object:

function doSomething(obj ) {
var a = obj.a;
var b = obj.b;

alert(a+','+b);
}

doSomething({ a:100 });
doSomething({ b:'Hello' });
doSomething({
a:'Hi',
b:'Bye'
});