javascript - JavaScriptCore Won't Pass string as NSObject * -

consider following jsexported objective-c class nsobject * property:

@protocol myobjectexport <jsexport> @property (nonatomic, strong) nsobject *myproperty; @end  @interface myobject : nsobject <myobjectexport> @end  @implementation myobject - (nsobject *)myproperty {     nslog(@"in myproperty");     return nullptr; } - (void)setmyproperty:(nsobject *)myproperty {     nslog(@"in setmyproperty"); } @end 

if execute code:

{     jscontext *context = [[jscontext alloc] init];     context[@"myobject"] = [[myobject alloc] init];     [context evaluatescript:@"var foo = myobject.myproperty; myobject.myproperty = foo;"]; } 

both myproperty , setmyproperty called.

but if execute code:

{     jscontext *context = [[jscontext alloc] init];     context[@"myobject"] = [[myobject alloc] init];     [context evaluatescript:@"myobject.myproperty = \"foo\";"]; } 

setmyproperty not called, presumably because "foo" not compatible nsobject *.

however, if execute code:

{     myobject *myobject = [[myobject alloc] init];     myobject.myproperty = @"foo"; } 

setmyproperty called.

of course, if replace nsobject * nsstring *, works fine. need property able hold variety of object types.

i don't control passed evaluatescript. however, there way can code things javascriptcore universally convert "foo" nsstring * prior passing objective-c callback? realize can intercept call on javascript side , necessary fiddling there, i'd avoid if possible.

if need hold 1 of many types should use id rather nsobject *. make generic pointer kind of void * in c.

even better use jsvalue * type since -[jsvalue is*] messages can figure out type passed. downside of though jsvalue * properties need backed jsmanagedvalue * ivars prevent retain cycles. see wwdc 2013 video 615, 2/3 of way through more on memory management issue.