how can I overwrite a prototype function?

**Thomas 'PointedEars' Lahn** · Jun 27 '08, 07:13 PM

Re: how can I overwrite a prototype function?

hzgt9b wrote:

I know how to overwrite a function. Normally this is what I would do:
function someFunction() { /* orig definition here */ }
//later in the execution stream I would do...
someFunction = function () { /* overwrite function definition */ }
The above works fine for me even when someFunction is originally
defined in a seperate frame other than the code that overwrites it
(obviously on the same domain).
>
What I don't know how to-do is overwrite a prototype function that
already loaded into memory on another frame (on the same domain). For
example:
>
//say, this prototype function is defined on a frame named
'frame1'
String.prototyp e.someOtherFunc tion() { /* define prototype
function here */ }

This is a syntax error. Prototype methods are defined like this instead:

String.prototyp e.someOtherFunc tion = function() {
// ...
};

Or like this, but that would overwrite all other methods and so is useful
for initialization of user-defined prototypes only:

String.prototyp e = {
someOtherFuncti on: function() {
// ...
}
};

You should avoid augmenting prototype objects of built-in objects for it
complicates programming a lot; String.prototyp e could be considered an
exception to this rule of thumb because for-in iteration over strings does
not yield useful results in all implementations and so one would probably
not use for-in then.

Problem is I don't know how to access the prototype function from
another frame.

window.parent.f rames["frame1"].Foo.prototype. bar
or
window.top.fram es["frame1"].Foo.prototype. bar

Depends on how deep your frameset is nested and where the method is defined.

I've tried
//assume we are not (executing) in 'frame1'
top.frame1.Stri ng.prototype.so meOtherFunction = function () { /*
overwrite function here */ }

This would accomplish what you want, but it would only affect the global
execution context of top.frame1, of course.

top.frame1.some OtherFunction = function () { /* overwrite
function here */ } //this just defines a new function in frame1

Actually, it only adds a property to top.frame1. It is
implementation-dependent whether this property will be available as a method
of the Global Object of the global execution context top.frame1 represents.

Is this possible? Can someone give me some pointers?

It does not make sense to overwrite a method in another global execution
context, unless this method is used in that execution context or subordered
local contexts.

PointedEars
--
Use any version of Microsoft Frontpage to create your site.
(This won't prevent people from viewing your source, but no one
will want to steal it.)
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**hzgt9b** · Jun 27 '08, 07:13 PM

Re: how can I overwrite a prototype function?

On Jun 7, 2:03 pm, Thomas 'PointedEars' Lahn <PointedE...@we b.de>
wrote:

hzgt9b wrote:

I know how to overwrite a function. Normally this is what I would do:
function someFunction() { /* orig definition here */ }
//later in the execution stream I would do...
someFunction = function () { /* overwrite function definition */ }
The above works fine for me even when someFunction is originally
defined in a seperate frame other than the code that overwrites it
(obviously on the same domain).

>

What I don't know how to-do is overwrite a prototype function that
already loaded into memory on another frame (on the same domain). For
example:

>

//say, this prototype function is defined on a frame named
'frame1'
String.prototyp e.someOtherFunc tion() { /* define prototype
function here */ }

>
This is a syntax error. Prototype methods are defined like this instead:
>
String.prototyp e.someOtherFunc tion = function() {
// ...
};
>
Or like this, but that would overwrite all other methods and so is useful
for initialization of user-defined prototypes only:
>
String.prototyp e = {
someOtherFuncti on: function() {
// ...
}
};
>
You should avoid augmenting prototype objects of built-in objects for it
complicates programming a lot; String.prototyp e could be considered an
exception to this rule of thumb because for-in iteration over strings does
not yield useful results in all implementations and so one would probably
not use for-in then.
>

Problem is I don't know how to access the prototype function from
another frame.

>
window.parent.f rames["frame1"].Foo.prototype. bar
or
window.top.fram es["frame1"].Foo.prototype. bar
>
Depends on how deep your frameset is nested and where the method is defined.
>

I've tried
//assume we are not (executing) in 'frame1'
top.frame1.Stri ng.prototype.so meOtherFunction = function (){ /*
overwrite function here */ }

>
This would accomplish what you want, but it would only affect the global
execution context of top.frame1, of course.
>

top.frame1.some OtherFunction = function () { /* overwrite
function here */ } //this just defines a new function in frame1

>
Actually, it only adds a property to top.frame1. It is
implementation-dependent whether this property will be available as a method
of the Global Object of the global execution context top.frame1 represents..
>

Is this possible? Can someone give me some pointers?

>
It does not make sense to overwrite a method in another global execution
context, unless this method is used in that execution context or subordered
local contexts.
>
PointedEars
--
Use any version of Microsoft Frontpage to create your site.
(This won't prevent people from viewing your source, but no one
will want to steal it.)
-- from <http://www.vortex-webdesign.com/help/hidesource.htm>- Hide quoted text -
>
- Show quoted text -

Thanks for the reply and info.

how can I overwrite a prototype function?

how can I overwrite a prototype function?

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