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Elhoej
Elhoej

Reputation: 751

Data isn't being passed from one viewcontroller to another

When I try to pass some variables from one VC to the other, the variables in the VC i'm passing to, doesn't get updated. Here is how I've done it so far:

VC 1

var note: String = ""
var reward: Int = 0
var deadline: Int = 0

VC 2

var vcOne = VcOne()
var note: String = "Some note..."
var reward: Int = 100
var deadline: Int = 988934

In the function where I pop VC 2, I pass the data from that one to update VC 1 like this:

func passData()
{
    vcOne.note = self.note
    vcOne.reward = self.reward
    vcOne.deadline = self.deadline

    navigationController?.popViewController(animated: true)
}

But when I print the values in VC 1 after I have passed, they are still empty or 0.

I have used this method to pass data before, but this time it doesn't seem to work. Should I be doing it differently? What's the best way to pass data like the way I showed?

EDIT: Here is my real code

VC 1:

class CreateMissionController: UIViewController, UITextViewDelegate
{
    var deadline: Int = 0
    var missionLatitude: Double = 0
    var missionLongitude: Double = 0


func handleSetLocation()
{
    let createMapController = CreateMapController()
    navigationController?.pushViewController(createMapController,animated: true)
}

VC 2

class CreateMapController: UIViewController, CLLocationManagerDelegate,     MKMapViewDelegate
{
    var createMissionController: CreateMissionController?
    var missionLatitude: Double?
    var missionLongitude: Double?
    var deadline: Int?


func handleChooseLocation()
{
    missionLatitude = missionLocation!.latitude
    missionLongitude = missionLocation!.longitude

    createMissionController?.missionLatitude = missionLatitude!
    createMissionController?.missionLongitude = missionLongitude!

    let timeInterval = deadlineDate?.timeIntervalSince1970
    let deadlineInt = Int(timeInterval!)

    createMissionController?.deadline = deadlineInt

    print(missionLatitude!)
    print(missionLongitude!)
    print(deadlineInt)

    navigationController?.popViewController(animated: true)
}

when I print in VC 2, they display the correct values, but if I try to print in VC 1 after I have executed the function in VC 2, they just print the default values.

Upvotes: 0

Views: 60

Answers (2)

Daniel Klöck
Daniel Klöck

Reputation: 21137

In VC2 you create a new VC1 with var vcOne = VcOne(). When passign your data, you are probably passing it to the wrong instance.

You should define the property as:

var vcOne: VC1

and pass the existing instance instead

Update

You have to set a reference to the mission VC:

func handleSetLocation()
{
    let createMapController = CreateMapController()
    createMapController.createMissionController = self
    navigationController?.pushViewController(createMapController,animated: true)
}

Upvotes: 1

Keuha
Keuha

Reputation: 295

VC1

var note: String = ""
var reward: Int = 0
var deadline: Int = 0

var vc2 = VcTwo()
vc2.vcOne = self

VC 2

var vcOne : VcOne
var note: String = "Some note..."
var reward: Int = 100
var deadline: Int = 988934

func passData()
{
    vcOne.note = self.note
    vcOne.reward = self.reward
    vcOne.deadline = self.deadline

    navigationController?.popViewController(animated: true)
}

As mentionned in my commentary, you're reassigning a new vcOne, so you set another object and don't get the data back. by assigning vc2.vcOne to self, you're telling vc2 to use your current object

Upvotes: 1

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