Subj : Re: How to pass boolean value from C++ back to script? (jsapi)
To   : netscape.public.mozilla.jseng
From : Jens Bannmann
Date : Mon Jan 03 2005 03:11 pm

Okay, with a little help from biesi on IRC I figured it out. I'll post
the simplified code below, don't forget to add some feedback in case of
invalid parameters. And make sure you don't pass the boolean back when
the user supplied null instead of a JS object - that will crash
mozilla...

For a full working example, see mozilla/xpinstall/src/nsJSInstall.cpp
(or bug 216399), search for confirmEx.

Best regards,
Jens


Reading the boolean parameter (argv[7] here):
|
|   JSObject* jsObject;
|   jsval jsCheckState;
|   PRBool checkState = PR_FALSE;
|
|   if (!JSVAL_IS_NULL(argv[7])
|       && JSVAL_IS_OBJECT(argv[7]))
|     jsObject = JSVAL_TO_OBJECT(argv[7]);
|     if (JS_GetProperty(cx, jsObject, "value", &jsCheckState)
|         && JSVAL_IS_BOOLEAN(jsCheckState))
|     {
|       JS_ValueToBoolean(cx, jsCheckState, &checkState);
|     }
|   }


Passing it back:
|
|   jsCheckState = BOOLEAN_TO_JSVAL(checkState);
|   JS_SetProperty(cx, jsObject, "value", &jsCheckState);

.