ios - Passing data back from a modal view in WatchKit -

when modally presenting, or pushing, interface controller can specify context parameter pass data new controller follows.

// push [self pushcontrollerwithname:@"mycontroller" context:[nsdictionary dictionarywithobjectsandkeys:someobject, @"somekey", ..., nil]];   // modal [self presentcontrollerwithname:@"mycontroller" context:[nsdictionary dictionarywithobjectsandkeys:someobject, @"somekey", ..., nil]];  

my question is, how can reverse?

say present controller modally user pick item list , return main controller, how can item has been picked?

i wrote full example uses delegation in watchkit, passing delegate instance in context, , calling delegate function modal : here full project example on github

here principale classes of example :

interfacecontroller.swift

this main controller, there label , button on view. when press button, presentitemchooser called , present modalview (modalinterfacecontroller). pass instance of interfacecontroller in context modal. important controller implements `modalitemchooserdelegate' functions (the protocol definition in modal file)

class interfacecontroller: wkinterfacecontroller, modalitemchooserdelegate {      @iboutlet weak var itemselected: wkinterfacelabel!     var item = "no item"      override func awakewithcontext(context: anyobject?) {         super.awakewithcontext(context)          // configure interface objects here.      }      override func willactivate() {         // method called when watch view controller visible user         itemselected.settext(item)         super.willactivate()      }      override func diddeactivate() {         // method called when watch view controller no longer visible         super.diddeactivate()     }      func didselectitem(itemselected: string) {         self.item = itemselected     }      @ibaction func presentitemchooser() {          self.presentcontrollerwithname("modalinterfacecontroller", context: self)      } } 

modalinterfacecontroller.swift

this class of modal controller. hold reference of previous controller (self.delegate = context as? interfacecontroller). when row selected, call delegate function didselectitem(selecteditem) before dismissing it.

protocol modalitemchooserdelegate {         func didselectitem(itemselected:string)     }      class modalinterfacecontroller: wkinterfacecontroller {          let rowid = "customtablerowcontroller"          let items = ["item 1", "item 2", "item 3", "item 4", "item 5"]          var delegate: interfacecontroller?          @iboutlet weak var customtable: wkinterfacetable!          override func awakewithcontext(context: anyobject?) {             super.awakewithcontext(context)             self.delegate = context as? interfacecontroller             // configure interface objects here.             println(delegate)             loadtabledata()         }          override func willactivate() {             // method called when watch view controller visible user              super.willactivate()         }          override func diddeactivate() {             // method called when watch view controller no longer visible             super.diddeactivate()         }          private func loadtabledata(){             customtable.setnumberofrows(items.count, withrowtype: rowid)             for(i, itemname) in enumerate(items){                 let row = customtable.rowcontrolleratindex(i) as! tablerowcontroller                 row.fillrow(itemname)              }          }          override func table(table: wkinterfacetable, didselectrowatindex rowindex: int) {             let selecteditem = items[rowindex]             self.delegate?.didselectitem(selecteditem)             self.dismisscontroller()         }       } 

this how pass data previous controller. if better way let me know, i'll take it. :)