Subj : Re: SM: run a script from a native function
To   : Shanti Rao <shantirao@yahoo.com>
From : Brendan Eich <brendan@meer.net>
Date : Thu Jan 08 2004 11:06 am

Shanti Rao wrote:

> This JS code calls my error reporter:
> 
> new Script("print('hello')\nasdf;").exec()

Are you sure the call to your error reporter happens within the call to 
new Script here?  It should be coming from the JS shell (or whatever you 
are running this in), when control unwinds from the outermost JS API 
entry point.

> 
> Oddly, though, this code doesn't. It just writes 'false' and stops.
> 
> JSScript* script =
> JS_CompileScript(cx,obj,"print('hello')\nasdf;",20,'filename',1);
> JSObject* o2 = JS_NewScriptObject(cx,script);
> JS_CallFunctionName(cx,o2,"exec",0,0,&rval);
> 
> Of course, that's the same as calling JS_EvaluateScript, but what 
> happens to the error reporter?

The error is a pending exception in cx, until control unwinds from the 
outermost JS API entry point (JS_Evaluate*, JS_Execute*, JS_Call*), 
which will report uncaught exceptions.

Errors as exceptions allow the script that's calling your native 
function to catch errors with a try statement.

/be

.