ios - View not displaying for childViewController of another ChildViewController -

i'm having issue multi-level hierarchy of childviewcontrollers in ios/swift. there 3 layers current setup lowest-to-highest:

1. infoviewcontroller
2. selectionviewcontroller
3. mainviewcontroller

the infoviewcontroller has view loaded xib.

selectionviewcontroller contains uistackview infoviewcontroller , uibutton.

mainviewcontroller top-level vc embedded in uinavigationcontroller.

the problem

when add infoviewcontroller , it's view directly mainviewcontroller works great.

func setupinfoviewcontrollerdirectlyonmainvc () {     addchildviewcontroller(infoviewcontroller)     infoviewcontroller.view.embedinside(otherview: infocontainerview)     infoviewcontroller.didmove(toparentviewcontroller: self) } 

however, if add selectionviewcontroller mainviewcontroller using same method, embedded infoviewcontroller doesn't update it's ui - looks untouched xib file controlling. when not embedded in selectionviewcontroller behaves expected.

as shown below, ui visible, changes made via asking it's viewcontroller not show - looks xib file created from.

below class setup starting basicinfoview followed 3 viewcontrollers listed above.

basicinfoview

class plbasicinfoview: pldesignableviewfromxib {      //     // mark: outlets     //     //      @iboutlet weak var photoview: pfroundimageview!     @iboutlet weak var titlelabel: uilabel!     @iboutlet weak var subtitlelabel: uilabel!       var imagefile:pffile? {         didset {             photoview.file = imagefile             photoview.loadinbackground()         }     }      //     // mark: initialization     //     //      override var nameofxib: string {         return "plbasicinfoview"     }      override var intrinsiccontentsize: cgsize {         return cgsize(width: super.intrinsiccontentsize.width, height: 56)     }  } 

basicinfoviewcontroller

class plbasicinfoviewcontroller: uiviewcontroller {      /**      basicinfoview managed controller.      */     var basicinfoview = plbasicinfoview()      /**      master stack view contains subviews.      */     var stackview = uistackview()       /**      pffile representing image displayed in imageview. setting valid imagefile object automatically laods image server. if set nil, defaultimage displayed instead.      */     var imagefile: pffile? {         didset {             if imagefile != nil {                 basicinfoview.imagefile = imagefile             } else {                 basicinfoview.photoview.image = defaultimage             }         }     }      /**      default uiimage displayed in imageview if there no imagefile assigned.      */     var defaultimage: uiimage! {         return #imageliteral(resourcename: "ios7-camera-outline")     }       /**      main text of infoview      */     var titletext:string? {         didset {             basicinfoview.titlelabel.ishidden = (titletext == nil)             basicinfoview.titlelabel.text = titletext         }     }      /**      secondary text of infoview. displays under titletext.      */     var subtitletext:string? {         didset {             basicinfoview.subtitlelabel.ishidden = (subtitletext == nil)             basicinfoview.subtitlelabel.text = subtitletext         }     }      /**      embed our stackview main view. custom embedinsider(otherview:uiview) method (uiview extension) take care of subview additional layout constraints.      */     func setupstackview () {         stackview.embedinside(otherview: view)         stackview.axis = .vertical         stackview.addarrangedsubview(basicinfoview)     }      override     func viewdidload() {         super.viewdidload()         setupstackview()     }   } 

selectionviewcontroller

class plselectableinfoviewcontroller: uiviewcontroller {       /**      if true, info view shown , selection button hidden.      */     var isassigned = false {         didset {             selectionbutton.ishidden = isassigned             infoview.ishidden = !isassigned         }     }       /**      view controller dispaying object in question.      */     var infoviewcontroller: plbasicinfoviewcontroller! {         return plbasicinfoviewcontroller()     }      private     var infoview: uiview!      /**      button on bottom of stack. intended allow user assign new value contact property.      */     var selectionbutton = plbutton()      /**      stack view containing subviews.      */     var stackview = uistackview()       //     // mark: uiviewcontroller overrides     //     //      override     func viewdidload() {         super.viewdidload()         setupstackview()         addinfoview()     }       private     func setupstackview () {         stackview.embedinside(otherview: view)         stackview.axis = .vertical     }      private     func addinfoview () {         addchildviewcontroller(infoviewcontroller)         infoview = infoviewcontroller.view         stackview.addarrangedsubview(infoview)         infoviewcontroller.didmove(toparentviewcontroller: self)     }  } 

some non-relevant code has been removed

notes

please note in practice, both basicinfoviewcontroller , selectionviewcontroller subclassed. example, have contactinfoviewcontroller can passed contact object , display full name, company name , photo (as explained above, works fine). there subclass of selectionviewcontroller complement this: contactselectionviewcontroller. contactselectionviewcontroller has contact object property can assigned , passed embedded contactinfoviewcontroller - point @ data not displayed. have included these subclasses below additional reference.

contactinfoviewcontroller

again, works when placed directly mainviewcontroller.

class plcontactinfoviewcontroller: plbasicinfoviewcontroller {      /**      contact object managed controller.      */     var contact: plcontact? {         didset {             if contact == nil {                 titletext = "not set"                 subtitletext = nil                 return             }             contact?.fetchifneededinbackground(block: { (object, error) in                 if let _ = object as? plcontact {                     self.updatewithcontact()                 }             })         }     }      override     var defaultimage: uiimage! {         return #imageliteral(resourcename: "ios7-contact-outline")     }       private     func updatewithcontact () {         if let c = contact {             titletext = c.fullname             imagefile = c.photo             c.company?.fetchifneededinbackground(block: { (object, error) in                 if let comp = object as? plcompany {                     self.subtitletext = comp.name                 } else {                     self.subtitletext = nil                 }             })         }     }  } 

contactselectionviewcontroller

this vc functions properly, embedded contactinfoviewcontroller not display data. reason, view contactinfoviewcontroller not being updated data when embedded inside controller.

class plcontactassignmentviewcontroller: plselectableinfoviewcontroller {       /**      contact selected contorller      */     var selectedcontact: plcontact? {         didset {             isassigned = !(selectedcontact == nil)             contactinfoviewcontroller.contact = selectedcontact         }     }       override     var infoviewcontroller: plbasicinfoviewcontroller! {         return plcontactinfoviewcontroller()     }       private     var contactinfoviewcontroller: plcontactinfoviewcontroller {         return infoviewcontroller as! plcontactinfoviewcontroller     }  } 

try

    var _infoviewcontroller: plbasicinfoviewcontroller?     var infoviewcontroller: plbasicinfoviewcontroller! {         if let vc = _infoviewcontroller {             return vc         }         _infoviewcontroller = plbasicinfoviewcontroller()         return _infoviewcontroller!     } 

or

lazy var infoviewcontroller: plbasicinfoviewcontroller = {         return plbasicinfoviewcontroller()     }() 

it might because initiating plbasicinfoviewcontroller every time when try access.

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