Use of constant (#define) in Swift Language – iOS

Swift Constant Test
Swift Constant Test

In Objective-C we are using a header file to create constant variables like as

// Objective-C
#define APP_ALERT_TITLE "Objective-C Constant"

Swift has new syntax to define the constant (#define)

// Swift
let APP_ALERT_TITLE = "Swift Constants"

Lets try

Create a swift file with the constants

import Foundation

class Constants {
    
    // MARK: List of Constants
    
    static let APP_ALERT_TITLE = "Swift Constants"
    static let SAMPLE_MESSAGE = "The alert is working !!"
}

Note : Here the MARK statement is also changed.

// Objective-C
#pragma mark -
#pragma mark List of Constants
// Swift
// MARK: List of Constants

Continue reading

Realm – mobile database with Swift

What is Realm?

Realm is a mobile database

Realm is a replacement for SQLite & Core Data.
It can save you thousands of lines of code & weeks of work,
and lets you craft amazing new user experiences.

Download the Realm framework for swift from https://realm.io/

import UIKit
import RealmSwift

class Person: Object {
    dynamic var name = ""
    dynamic var age = 0
}

class ViewController: UIViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // Initializing the object
        
        let personObj1 = Person()
        personObj1.name = "Ashish"
        personObj1.age = 25
        println("name of person : \(personObj1.name)")
        
        // Writing it to realm
        
        let realm = Realm()
        
        realm.write {
            realm.add(personObj1)
        }
        
        let personObj2 = Person()
        personObj2.name = "Darshak"
        personObj2.age = 27
        
        realm.write {
            realm.add(personObj2)
        }
        
        // Quering
        
        let r = Realm().objects(Person).filter("age > 24")
        
        println(r)
        
        // Queries are chainable
        
        let r2 = r.filter("name contains 'Ashish'")

        println(r2)
    }
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}

Output :

name of person : Ashish
Results<Person> (
	[0] Person {
		name = Ashish;
		age = 25;
	},
	[1] Person {
		name = Darshak;
		age = 27;
	}
)
Results<Person> (
	[0] Person {
		name = Ashish;
		age = 25;
	}
)

Happy Coding 🙂

How to work with WatchKit in Swift Language – iOS 8 #Tutorial #CounterWithWatch

Apple Watch represents a new chapter in the relationship people have with technology. Now you can deliver innovative new experiences to your customers on their wrist. And by adding WatchKit, you can take your apps even further by extending and enhancing their functionality on Apple Watch.

Lets learn how to work with WatchKit by an Counter Example.

Counter Watch Example
Counter Watch

Create New Project in XCode with Swift Language

New Project
New Project

Add Apple Watch Target in your Application

Add Target
Add Target

Select Apple Watch Target

Add Target Apple Watch
Add Target Apple Watch

Select Options for Target

Target Options
Target Options

Storyborad of watch

By adding target you will find the InterfaceController.swift and Interface.storyboard

Storyboard And Swift Files
Storyboard And Swift Files

Design watch with the controls

Design and reposition the controls with the properties of controls.

Design Controls in Watch
Design Controls in Watch

Now Time to do some code and connect the outlets

Connect Outlets
Connect Outlets

Code:

//  InterfaceController.swift

import WatchKit
import Foundation


class InterfaceController: WKInterfaceController {

    @IBOutlet weak var lblCounter: WKInterfaceLabel!
    var counter:Int = 0

    override func awakeWithContext(context: AnyObject?) {
        super.awakeWithContext(context)
        
        // Configure interface objects here.
    }

    override func willActivate() {
        // This method is called when watch view controller is about to be visible to user
        super.willActivate()
    }

    override func didDeactivate() {
        // This method is called when watch view controller is no longer visible
        super.didDeactivate()
    }
    
    @IBAction func upButtonPressed() {
        counter = counter + 1
        lblCounter.setText("\(counter)")
    }
    
    @IBAction func downButtonPressed() {
        counter = counter - 1
        lblCounter.setText("\(counter)")
    }
}

Download project with this stuff AppleWatchCounterDemo.zip

Thanks!

Happy Coding 😀

Passing data with Unwind Segue in Swift Language – iOS 8

Unwind Segue Data
Unwind Segue Data

We have learn about Work with Unwind Segue in Swift Language – iOS 8 in first tutorial. Now we will learn how to pass the data with unwind segue.

It just simple.

Continue with the same example project.

Take data variables which you want to get in the parent view.

For example,

class ViewController2: UIViewController {
    var data:String = "view 2 data"
    ....
}

To get data from first view controller we have to get data from source view controller like follows :

    @IBAction func unwindToVC(segue:UIStoryboardSegue) {
        if(segue.sourceViewController .isKindOfClass(ViewController2))
        {
            var view2:ViewController2 = segue.sourceViewController as ViewController2
            let alert = UIAlertView()
            alert.title = "UnwindSegue Data"
            alert.message = view2.data
            alert.addButtonWithTitle("Ok")
            alert.show()
        }
        if(segue.sourceViewController .isKindOfClass(ViewController3))
        {
            var view3:ViewController3 = segue.sourceViewController as ViewController3
            let alert = UIAlertView()
            alert.title = "UnwindSegue Data"
            alert.message = view3.data
            alert.addButtonWithTitle("Ok")
            alert.show()
        }
    }

Download project with this stuff UnwindSegueData.zip

Thanks!

Happy Coding 😀

Work with Unwind Segue in Swift Language – iOS 8

Unwind - Exit
Unwind – Exit

An unwind segue (sometimes called exit segue) can be used to navigate back through push, modal or popover segues (as if you popped the navigation item from the navigation bar, closed the popover or dismissed the modally presented view controller). On top of that you can actually unwind through not only one but a series of push/modal/popover segues, e.g. “go back” multiple steps in your navigation hierarchy with a single unwind action.

To enable the Unwind Segue you need to add some code first.

@IBAction func unwindToVC(segue: UIStoryboardSegue) {
}

You have to add this code in the view controller where you want to unwind (came back).

Unwind To View
Unwind To View

Suppose you want to came back from second or third view to first view then you have to add the code in first view.

Then just connect any control(Which contains action) with the unwind segue.

Unwind Segue
Unwind Segue

For check the particular view controller by unwind segue, use following code :

    @IBAction func unwindToVC(segue:UIStoryboardSegue) {
        if(segue.sourceViewController .isKindOfClass(ViewController2))
        {
            let alert = UIAlertView()
            alert.title = "UnwindSegue"
            alert.message = "Unwind from view 2"
            alert.addButtonWithTitle("Ok")
            alert.show()
        }
        if(segue.sourceViewController .isKindOfClass(ViewController3))
        {
            let alert = UIAlertView()
            alert.title = "UnwindSegue"
            alert.message = "Unwind from view 3"
            alert.addButtonWithTitle("Ok")
            alert.show()
        }
    }

Download project with this stuff UnwindSegue.zip

In next tutorial you will find the topic Passing data with Unwind Segue in Swift Language – iOS 8

Thanks!

Happy Coding 😀