CODEWITHSUNDEEP
iosxcodeswift
Erik Lydecker
Erik Lydecker

Reputation: 717

Use functions from other files in Swift Xcode

How can I write a function in a separate swift file and use it (import it) to my ViewController.swift file? I have written a lot of code and all of the code is in the ViewController.swift file, I really need to make this look good and place functions on separate files, for cleaner code. I have functions dealing with parsing HTML, functions dealing with ordering results, presenting results, responding to user actions, etc. Many thanks for any help!

if let htmlString = String(contentsOfURL: checkedUrl, encoding: NSUTF8StringEncoding, error: nil) {


                // Parsing HTML

                let opt = CInt(HTML_PARSE_NOERROR.value | HTML_PARSE_RECOVER.value)

                var err : NSError?

                var parser = HTMLParser(html: htmlString, encoding: NSUTF8StringEncoding, option: opt, error: &err)

                var bodyNode = parser.body


                // Create an array of the part of HTML you need

                if let inputNodes = bodyNode?.findChildTags("h4") { //inputNodes is an array with all the "h4" tag strings

                    for node in inputNodes {

                        let result = html2String(node.rawContents)

                        println("Nyheter: \(result)")

                    }
                }

When I add that function to a separate swift file, how can I use it in my ViewDidLoad method using a "shorthand"? A short keyword that grabs that chunk of code and use it?

Upvotes: 9

Views: 17201

Answers (3)

Zonily Jame
Zonily Jame

Reputation: 5359

You can create a Utils class, filled with static variables/functions

For example:

class Utils {
    static func convert(to variable: String) -> Int? {
        ... do some stuff to variable
        return newVariable
    }
}

// on your ViewController.swift

override func viewDidLoad() {
    super.viewDidLoad()
    if let converted = Utils.convert(to: "123") {
        print(converted)
    }
}

By making use of static functions you can access them anywhere and everywhere to reuse them.

------------------

Another way is to make use of extensions

For example: 

extension String {
    var toInt: Int? {
        return Int(self)
    }
}

// on your ViewController.swift

override func viewDidLoad() {
    super.viewDidLoad()

    if let converted = "SomeValue".toInt {
        print(converted)
    }
}

Both of these can be used in many different scenarios.

Upvotes: 3

Nurdin
Nurdin

Reputation: 23883

You need to use singletons.

Create NSObject in User.swift

import Foundation
import UIKit

class User: NSObject {
    var name: String = 0

    func getName() -> String{
        name = "Erik Lydecker"
        return name
    }
}

Then initialize your object and trigger the method there.

ViewController.swift

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        let instanceOfUser = User()
        instanceOfUser.getName() // Erik Lydecker
    }
}

Upvotes: 5

Teemu Kurppa
Teemu Kurppa

Reputation: 4839

Easy. You just create a new Swift file into your Xcode project (File - New - File - Swift file or just ⌘-N) and put your functions and classes there. No need to import anything in your view controller file as both files are part of the same package and thus see each others functions and types (unless marked as private).

func parseHtml(url: NSURL) -> String { ... your code goes here ... }

Upvotes: 11

Related Questions