swift - How to pass value from navigationController to TabBarController -

i have login project. first view controller navcontroller , need pass user data tabbarcontroller have 3 navigationcontrollers.

i tried this.

let opennewvc = self.storyboard?.instantiateviewcontrollerwithidentifier("mainnavid") as! uitabbarcontroller //opennewvc.token = token! self.navigationcontroller?.pushviewcontroller(opennewvc, animated: true) 

you can pass data first view controller view controllers embedded below in uitabbarcontroller.

uitabbarcontroller -> uinavigationcontroller -> uiviewcontroller

you need traverse viewcontrollers instance of uitabbarcontroller , uinavigationcontroller in order instance of uiviewcontroller. once instance of 'uiviewcontroller' embedded uitabbarcontroller, can assign data required.

for example

if let tabbarcontroller = self.storyboard?.instantiateviewcontrollerwithidentifier("mainnavid") as? uitabbarcontroller {      // need view controllers array tabbarcontrollers uinavigationcontrollers     if let navigationcontrollers = tabbarcontroller.viewcontrollers as? [uinavigationcontroller] {     navigationcontroller in navigationcontrollers {         //now need viewcontrollers navigationcontroller stack,           let viewcontrollers = navigationcontroller.viewcontrollers          //now can assing desired value in viewcontrollers, assuming need assign same value in viewcontroler         viewcontroller in viewcontrollers {          }         }     }     } 

the best way pass data in kind of architecture using singleton, assume created class session member variable token.

class session {      //singleton     static let sharedinstance = session()      //token assign , can use through out application     var token : string? = nil } 

now, can assign token while pushing uitabbarcontroller.

 let opennewvc = self.storyboard?.instantiateviewcontrollerwithidentifier("mainnavid") as! uitabbarcontroller session.sharedinstance.token = token     //opennewvc.token = token! self.navigationcontroller?.pushviewcontroller(opennewvc, animated: true) 

same token can use within uiviewcontroller

override func viewdidload() {     super.viewdidload()      if let token = session.sharedinstance.token {         //now have assigned token     } }