reactive cocoa - Is there something similar to $scope.$watch for NSMutableArray -

i've been struggling day working correct. have nsmutablearray of items. during application lifecycle, app push , pop objects in there. can on angularjs side $scope.$watch. i've been using reactivecocoa in meantime of behavior

essentially i'd block fire on these events.

-(void)fetchallitems; -(void)push:(id)item; -(void)pop:(nsuinteger)index;

i tried reactivecocoa never fires!

[racobserve(singletonstore, items) subscribenext:^(nsarray *wholearray) {         nsuinteger count = [wholearray count];         [self.offercirclebutton settitle:[nsstring stringwithformat:@"%d", count]]  }]; 

the items property declared in singletonstore object as

@property (nonatomic, copy) nsarray *items; 

the getter , setter nsmutablearray private variable

@interface shsingletonstore() {     nsmutablearray *_items; } @end  -(nsarray *)items {     return [_items copy]; }  -(void)setitems:(nsarray *)items{     if([_items isequaltoarray:items] == no){         _items = [items mutablecopy];     } } 

essentially i'd block fire on these events.

-(void)fetchallitems; -(void)push:(id)item; -(void)pop:(nsuinteger)index;

if saying want signal sends value whenever of methods called, can -rac_signalforselector:, so:

sel fetchallsel = @selector(fetchallitems); racsignal *fetchallsignal = [singletonstore rac_signalforselector:fetchallsel];  sel pushsel = @selector(push:); racsignal *pushsignal = [singletonstore rac_signalforselector:pushsel];  sel popsel = @selector(pop:); racsignal *popsignal = [singletonstore rac_signalforselector:popsel];  @weakify(self); [[racsignal merge:@[ fetchallsignal, pushsignal, popsignal ]] subscribenext:^(id _) {      @strongify(self);     [self.offercirclebutton settitle:[nsstring stringwithformat:@"%d", singletonstore.items.count]]  }]; 

this solution kind of gross, because each of individual merged signals sends different type of value (so end signal can send 3 different types of value, not cool), if ignoring value can perform side effect based on global state, doesn't matter.