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Function Context

Perhpas somebody can give me a hand with this little problem.

Given:

var object; -- an object
var func; -- a function call back

Now, I want to know how to get the following effect:

object.func = func;
object.func();

function func (somethingelse) {
this.something = somethingelse;
}

such that 'this' referes to 'object' without having to make 'func' a
member of 'object'. I tried `with (object) {func ();}` which I realized
wouldn't do that job.

Thanks,

Brett Foster
Jul 23 '05
10 1623
Michael Winter wrote:
On Fri, 07 Jan 2005 16:01:40 -0500, Brett Foster
<fo************ ****@ioctl.ca> wrote:

[snip]
object.func = func;
object.func();

function func (somethingelse) {
this.something = somethingelse;
}

func.call(objec t);

extending the call to include any arguments that the function, func,
should receive.

If this is for general Internet use (or for any environment that
features any JScript version earlier than 5.5 [which usually means IE5
or earlier]), you should be prepared to emulate the call method:

if(Function.pro totype
&& ('function' != typeof Function.protot ype.call))
{
Function.protot ype.call = function(o) {var p = '__call', r;
while('undefine d' != typeof o[p]) {p += p;}
o[p] = this; r = o[p](); delete o[p]; return r;
};
}

If the object in question might be a host object (such as an element
reference), remove the while statement and delete operator (otherwise
IE will error) and don't use the same property name contained in the
local variable, p.

[snip]

Hope that helps,
Mike


Thanks!!!

Brett
Jul 23 '05 #11

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