mvvm - Swift - How to use a closure to fire a function in a view model? -

i watching video series

swift talk #5 connecting view controllers url: https://talk.objc.io/episodes/s01e05-connecting-view-controllers

in video series remove prepareforsegue , use app class handle connection between different view controllers.

i want replicate this, in current view model; don't how connect view controllers through view model (or if you're meant to)

in code, @ github: https://github.com/objcio/s01e05-connecting-view-controllers/blob/master/example/appdelegate.swift

they use within view controller

var didselect: (episode) -> () = { _ in }

this runs;

func showepisode(episode: episode) {         let detailvc = storyboard.instantiateviewcontrollerwithidentifier("detail") as! detailviewcontroller         detailvc.episode = episode         navigationcontroller.pushviewcontroller(detailvc, animated: true)     } 

in same way, want use viewcontroller use viewmodel menu button press (relying on tag).

my code follows;

struct mainmenuviewmodel {     enum mainmenutag: int {         case newgametag = 0     }      func menubuttonpressed(tag: int) {         guard let tagselected = mainmenutag.init(rawvalue: tag) else {             return         }         switch tagselected {         case .newgametag:             print ("pressed new game btn")             break         }     }      func menubtndidpress(tag: int) {         print ("you pressed: \(tag)")         // switch here          // go next view controller?  should view model know navigation controllers, pushing, etc?     } }  class mainmenuviewcontroller: uiviewcontroller {      @iboutlet var mainmenubtnoutletcollection: [uibutton]!      var didselect: (int) -> () = { _ in }      override func viewdidload() {         super.viewdidload()     }      @ibaction func mainmenubtnpressed(_ sender: uibutton) {         let tag = (sender).tag         self.didselect(tag)      } } 

what don't understand how connect command

self.didselect(tag)

to function

func menubuttonpressed(tag: int)

within viewmodel

as understand it, according swift talk video idea view controller "plain" , view model handles major stuff, menu button presses , moving different view controllers necessary.

how connect didselect item viewmodel function?

thank you.

you should set didselect property controller here:

func showepisode(episode: episode) {     let detailvc = storyboard.instantiateviewcontrollerwithidentifier("detail") as! detailviewcontroller     detailvc.episode = episode     detailvc.didselect = { episode in         // whatever need        // example dismiss detailvc        self.navigationcontroller.popviewcontroller(animated: true)        // or call model methods        self.model.menubuttonpressed(episode)     }     navigationcontroller.pushviewcontroller(detailvc, animated: true) }