Subj : Re: Function name from JSObject
To   : JZ <jamilz@citlink.net>
From : Brendan Eich <brendan@meer.net>
Date : Fri Feb 07 2003 10:30 am

JZ wrote:

>I'm creating a bunch of JS functions using JS_DefineFunction, all mapped to
>an internal C function, 'do_my_c_function'.
>
>    do_my_c_function(JSContext *cx, JSObject *obj, uintN argc, jsval *argv,
>jsval *rval)
>
>What I want to know from these args is what was the function name that the
>user called in JS? Since I've mapped many JS functions to this one C
>function, knowing the name of the function called allows me to take the
>right action.
>
>Is that possible? Can I get the JS function name from the JSObject? How?
>
Use JS_GetFunctionId (new API; use JS_GetFunctionName only if you're 
stuck on an older version of the engine):

    JSObject *callee = JSVAL_TO_OBJECT(argv[-2]);
    JSFunction *fun = (JSFunction *) JS_GetPrivate(cx, callee);
    const JSString *funidstr = JS_GetFunctionId(fun);

    /* Now dispatch based on the characters in funidstr, using 
JS_GetStringChars */
    . . .

Or for faster dispatching, you might set a reserved slot in each 
function object to tell the underlying native function or code you want 
to execute.  See JS_SetReservedSlot.

>I'm hoping I don't have to map each function to a separate function.
>

Nope, no need for that.

/be

>
>JZ
>
>
>  
>

.