ios - How do I get the "old value" from a ReactiveCocoa signal? -


if i'm using racable this:

[racablewithstart(self.myprop) subscribenext:^(id x) {    // stuff  }];

how can can access old value of myprop (before change caused signal fire)? can access this:

[racablewithstart(self.myprop) subscribenext:^(id x) {    // stuff    id newvalue = x;    id oldvalue = rac_oldvalue; }];

i have used snippet success: 

[[object rac_valuesandchangesforkeypath:@"property" options:nskeyvalueobservingoptionold observer:self] subscribenext:^(ractuple *tuple) {     id newobject = tuple.first;     nsdictionary *change = tuple.second;     id oldobject = change[nskeyvaluechangeoldkey]; }];

source: reactivecocoa documentation


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