Subj : Re: question about javascript functions
To   : netscape.public.mozilla.jseng
From : Ludovic Delabre
Date : Wed Feb 09 2005 01:15 am

Well if I try from what you gave me, I got:
Assertion failure: root_points_to_gcArenaPool, at 
\js-1.5-rc6a\js\src\jsgc.c:972
Is that it ?

I can get rid of the crash by taking out the call to JS_AddRoot()...

hum... but somehow I got the idea working using "only" JS_CompileFunction ?
And from what I read from spidermonkey's source, the define property is 
already done there...  so why all the extra code ?

But maybe I miss somethin'... :-)

And why can't you call evaluateScript() anymore ? Works fine here...

Good night,
Ludovic

Béatrice Philippe wrote:
> what i'm doing is :
> 1. reading each function body
> 2. if a function contains some javascript statements my app doesn't want, my 
> app modifies the javascript function body  (that's what i try to).
> 
> The purpose is :
> when my app changes the body of a javascript function, this function must be 
> called everywhere and works.
> 
> I tried this example  :
> here are two functions :
> function fun1() {
>  var i = 'hello';
>  return i.toString();
> }
> 
> function fun2() {
>  var j = 'hello from fun2';
>   var x = fun1();
>  return x.toString();
> }
> somwhere in the html document:
> <A href=..... onclick="javascript:fun1();".....>
> if we do : 'js_evaluateScript()' for the onclick event: it works.
> 
> now, my app wants to change fun1 like this:
> JSstring aBody = js_decompileFunctionBody(...);
> char * aBody_char = js_GetStringBytes(...aBody);
> .... here we change the content of aBody_char....
> JSFunction *new_fun = js_compileFunction(contextOfGlobalObject, 
> GlobalObject, aBody_char, strlen(aBody_char),.....);
>  JSObject * childObject = JS_GetFunctionObject(new_fun);
>  JS_AddRoot(contextOfGlobalObject,&childObject);
> 
>  jsval rval = OBJECT_TO_JSVAL(childObject);
> JSObject *clonedFunc = JS_CloneFunctionObject(contextOfGlobalObject, 
> childObject, GlobalObject);
>  JS_DefineProperty(contextOfGlobalObject, GlobalObject, "fun1",
>                          OBJECT_TO_JSVAL(childObject), nsnull, nsnull,
>                          JSPROP_ENUMERATE | JSPROP_PERMANENT));
> 
> here, the function fun1 has been changed. Now, We can' t use 
> js_evaluateScript() anymore to play the 'onclick' event, but we must use 
> js_callFunctionValue() (or js_callFunction()) to call fun1 (and for that, we 
> must know that the onclick event is a function call :-)). This solution 
> works.
> 
> BUT: if we want to call fun2 function: it crashes since fun1 has changed and 
> spidermonkey cannot resolve
>  "x=fun1()" statement in fun2. Why ????? pointer lost ?
> if we don't change fun1 body, calling fun2 works well ! strange !!!!
> 
> Any idea ?
> Thank you.

.