objective c - Undefined symbols "_OBJC_CLASS_$_" error -

my project written in applescriptobjc , objective-c. have nstabviewdelegate, must written in objc:

#import <cocoa/cocoa.h> #import "msitems.h"   @interface mstabview : nstabview<nstabviewdelegate>  - (void)tabview:(nstabview *)tabview willselecttabviewitem:(nstabviewitem *)tabviewitem;  @end  @implementation mstabview  - (void)tabview:(nstabview *)tabview willselecttabviewitem:(nstabviewitem *)tabviewitem {       if ([[tabviewitem identifier] intvalue] == 1) {         [msitems mymethod];     }   }  @end 

msitems class written in applescriptobjc, created header file, contains method need called other classes.

#import <cocoa/cocoa.h>  @class msitems; @interface msitems : nsobject  + (void) mymethod;  @end 

in asobjc class have:

script msitems     property parent : class "nsobject"      on mymethod()        --stuff     end mymethod end script 

but app doesn't compile , error:

undefined symbols architecture x86_64: "_objc_class_$_msitems", referenced from:     objc-class-ref in mstabview.o ld: symbol(s) not found architecture x86_64 clang: error: linker command failed exit code 1 (use -v see invocation)