Swift set variable to another ViewController

Question

I have two tabs. And i want to set data from one tab to another. For example i have a code that switch to another tab:

func foundCode(code: String) {
    print("Code has been found: \(code)")
    // MySecondViewController.codeSetter(code);
    self.tabBarController?.selectedIndex = 1;
}

What is the best way to set it? Or maybe delegate this variable... But how ?

In first tab i calculated code and after all operations i want to switch tab and show information based on this code. — Arti, Oct 02 '15 at 08:04

score 0 · Answer 1 · answered Oct 02 '15 at 08:10

0

Simple example for you using NSUserDefaults:

Store your data into first tab:

let testInstance = 1
NSUserDefaults.standardUserDefaults().setInteger(testInstance, forKey: "pass")

Now in another tab you can read that data from memory this way:

let instanceFromAnotherTab = NSUserDefaults.standardUserDefaults().integerForKey("pass")
print(instanceFromAnotherTab)

Hope it helps.

answered Oct 02 '15 at 08:10

Dharmesh Kheni

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can i do this with "segue" ?? – Arti Oct 02 '15 at 08:31
1

This is very bad practice, storing and reading from UserDefaults, every time you change between tabs. Better way: http://stackoverflow.com/a/21271948/3207979 – Dejan Skledar Oct 02 '15 at 08:56
Can you explain why this is a bad practice because I have never seen any down side of `NSUserDefaults`. @DejanSkledar – Dharmesh Kheni Oct 02 '15 at 09:24
I'll just say, that things already get unnecessarily complicated, when you try to save a Custom object to NSUserDefaults. – Dejan Skledar Oct 02 '15 at 09:29
This is even worse than using the appDelegate to pass data between controllers. – Abizern Oct 02 '15 at 10:41
1

here are apple allow to setIntegerForKey then why that is not good @abizen and dejan Skleder please review this: https://developer.apple.com/library/mac/documentation/Cocoa/Reference/Foundation/Classes/NSUserDefaults_Class/index.html#//apple_ref/occ/instm/NSUserDefaults/setInteger:forKey: And if realy not got then apple have to remove NSUserDefault from development side – Nitin Gohel Oct 02 '15 at 10:52

score 0 · Accepted Answer · answered Oct 02 '15 at 10:32

If you set a variable in your first controller like:

var code:String!

and in your function:

func foundCode(code: String) {
    print("Code has been found: \(code)")
    self.code = code

    // MySecondViewController.codeSetter(code);
    self.tabBarController?.selectedIndex = 1;
}

I think you should be able to access it in your second controller (i think the variables you declare in top are accessible in all of your classes)

Swift set variable to another ViewController

2 Answers2