Extensions

The app uses several Swift extensions to add convenient functionality to standard types and UIKit classes.

Colors Extension

Custom color palette for consistent theming throughout the app. Location: Extensions/Colors.swift:12

Named Colors

Background

UIColor

Primary background color for the app

LabelBackground

UIColor

Background color for label containers

Yellow

UIColor

Accent yellow color

Blue

UIColor

Accent blue color for interactive elements

Red

UIColor

Primary red accent color (TikTok brand color)

Implementation

import UIKit

extension UIColor {
    static let Background = UIColor(named: "Background")!
    static let LabelBackground = UIColor(named: "LabelBackground")!
    static let Yellow = UIColor(named: "Yellow")!
    static let Blue = UIColor(named: "Blue")!
    static let Red = UIColor(named: "Red")!
}

Usage

// Set view background
view.backgroundColor = .Background

// Set button tint
button.tintColor = .Red

// Set label background
label.backgroundColor = .LabelBackground

String Extension

Utility functions for string formatting and number conversion. Location: Extensions/String.swift:11

Methods

format(decimal:maximumDigits:minimumDigits:)

static func

Formats a decimal number as a string with specified precisionParameters:

decimal: Float - The number to format
maximumDigits: Int - Maximum fraction digits (default: 1)
minimumDigits: Int - Minimum fraction digits (default: 1)

Returns: String? - Formatted number string

Implementation

import Foundation

extension String {
    static func format(decimal: Float, 
                      _ maximumDigits: Int = 1, 
                      _ minimumDigits: Int = 1) -> String? {
        let number = NSNumber(value: decimal)
        let numberFormatter = NumberFormatter()
        numberFormatter.maximumFractionDigits = maximumDigits
        numberFormatter.minimumFractionDigits = minimumDigits
        return numberFormatter.string(from: number)
    }
}

Usage Examples

Basic Formatting
Custom Precision
No Decimals

let formatted = String.format(decimal: 3.14159)
// Returns: "3.1"

let precise = String.format(decimal: 3.14159, 3, 2)
// Returns: "3.142" (max 3 digits, min 2 digits)

let whole = String.format(decimal: 42.0, 0, 0)
// Returns: "42"

Number Extension

Extends Int with social media number formatting (K for thousands, M for millions). Location: Extensions/Number.swift:11

Methods

shorten()

func

Converts large numbers to shortened format with K or M suffixReturns: String - Formatted number stringExamples:

1,234 → “1.2K”
1,500,000 → “1.5M”
999 → “999”

Implementation

import Foundation

extension Int {
    /**
     * Shorten the number to *thousand* or *million*
     * - Returns: the shorten number and the suffix as *String*
     */
    func shorten() -> String {
        let number = Double(self)
        let thousand = number / 1000
        let million = number / 1000000
        
        if million >= 1.0 {
            return "\(round(million * 10) / 10)M"
        }
        else if thousand >= 1.0 {
            return "\(round(thousand * 10) / 10)K"
        }
        else {
            return "\(self)"
        }
    }
}

Usage Examples

Likes Count
Followers
Small Numbers

let likes = 15300
likeCountLabel.text = likes.shorten()
// Displays: "15.3K"

let followers = 2500000
followerLabel.text = "\(followers.shorten()) followers"
// Displays: "2.5M followers"

let views = 847
viewLabel.text = views.shorten()
// Displays: "847"

URL Extension

Utility methods for URL scheme manipulation used in video streaming. Location: Extensions/URL.swift:11

Methods

convertToRedirectURL(scheme:)

func

Adds a custom scheme prefix to trigger AVAssetResourceLoaderDelegateParameters:

scheme: String - Prefix to add to the URL scheme

Returns: URL? - Modified URL with custom schemeExample: https://example.com/video.mp4 → httpsstreaming://example.com/video.mp4

convertFromRedirectURL(prefix:)

func

Removes custom scheme prefix to restore original URLParameters:

prefix: String - Prefix to remove from the URL scheme

Returns: URL? - Restored original URL

Implementation

import Foundation

extension URL {
    /// Adds the scheme prefix to a copy of the receiver.
    func convertToRedirectURL(scheme: String) -> URL? {
        var components = URLComponents(url: self, resolvingAgainstBaseURL: false)
        let schemeCopy = components?.scheme ?? ""
        components?.scheme = schemeCopy + scheme
        return components?.url
    }
    
    /// Removes the scheme prefix from a copy of the receiver.
    func convertFromRedirectURL(prefix: String) -> URL? {
        guard var comps = URLComponents(url: self, resolvingAgainstBaseURL: false) 
        else { return nil }
        guard let scheme = comps.scheme else { return nil }
        comps.scheme = scheme.replacingOccurrences(of: prefix, with: "")
        return comps.url
    }
}

Usage Examples

Video Streaming
Restore Original URL

let videoURL = URL(string: "https://example.com/video.mp4")!

// Convert to streaming URL to trigger custom resource loader
guard let streamingURL = videoURL.convertToRedirectURL(scheme: "streaming") else {
    print("Could not convert URL")
    return
}
// streamingURL: httpsstreaming://example.com/video.mp4

let asset = AVURLAsset(url: streamingURL)
asset.resourceLoader.setDelegate(self, queue: .main)

let streamingURL = URL(string: "httpsstreaming://example.com/video.mp4")!

guard let originalURL = streamingURL.convertFromRedirectURL(prefix: "streaming") 
else {
    return
}
// originalURL: https://example.com/video.mp4

// Use original URL for caching or network requests
let request = URLRequest(url: originalURL)

UIKit Extensions

Utility extensions for UIViewController and UIView classes. Location: Extensions/UIKit Extensions.swift

UIViewController Extension

Helper methods for common view controller operations.

Methods

getStatusBarHeight()

func

Returns the height of the status bar for the current windowReturns: CGFloat - Status bar height in points

showAlert(_:title:)

func

Displays an alert dialog with a messageParameters:

message: String - Alert message content
title: String? - Optional alert title

Implementation

import UIKit

extension UIViewController {
    /// Status Bar Height
    func getStatusBarHeight() -> CGFloat {
        let window = UIApplication.shared.windows.filter { $0.isKeyWindow }.first
        return window?.windowScene?.statusBarManager?.statusBarFrame.height ?? 0
    }
    
    /// Display an alert view if the function is not implemented
    func showAlert(_ message: String, title: String? = nil) {
        // Check if one has already presented
        if let currentAlert = self.presentedViewController as? UIAlertController {
            currentAlert.message = message
            return
        }
        
        let alertController = UIAlertController(title: title, 
                                               message: message, 
                                               preferredStyle: .alert)
        alertController.addAction(UIAlertAction(title: "OK", 
                                               style: .cancel, 
                                               handler: nil))
        self.present(alertController, animated: true, completion: nil)
    }
}

Usage Examples

Status Bar Height
Show Alert

class ProfileViewController: UIViewController {
    func setupView() {
        let statusBarHeight = getStatusBarHeight()
        let collectionViewLayout = ProfileCollectionViewFlowLayout(
            navBarHeight: statusBarHeight
        )
        // Use layout...
    }
}

@objc func setBackgroundSound() {
    self.showAlert("Background Sound Function is not implemented yet")
}

// With custom title
func handleError(_ error: Error) {
    self.showAlert(error.localizedDescription, title: "Error")
}

UIView Extension

Utility methods for view styling and layout.

Methods

makeRounded(color:borderWidth:)

func

Makes a view circular with optional borderParameters:

color: UIColor - Border color
borderWidth: CGFloat - Width of the border

Note: View becomes circular based on its height. Best used with square views.

Implementation

extension UIView {
    func makeRounded(color: UIColor, borderWidth: CGFloat) {
        self.layer.borderWidth = borderWidth
        self.layer.masksToBounds = false
        self.layer.borderColor = color.cgColor
        self.layer.cornerRadius = self.frame.height / 2
        self.clipsToBounds = true
    }
}

Usage Examples

Profile Image
Circular Button
IBOutlet with didSet

override func layoutSubviews() {
    super.layoutSubviews()
    profileImgView.makeRounded(color: .white, borderWidth: 1)
}

override func layoutSubviews() {
    super.layoutSubviews()
    followBtn.makeRounded(color: .clear, borderWidth: 0)
    musicBtn.makeRounded(color: .clear, borderWidth: 0)
}

@IBOutlet weak var profileImgView: UIImageView! {
    didSet {
        profileImgView.layer.cornerRadius = profileImgView.frame.width / 2
        profileImgView.layer.borderWidth = 1
        profileImgView.layer.borderColor = UIColor.Background.cgColor
    }
}

Extension Organization

All extensions are organized in the Extensions/ directory:

Extensions/
├── Colors.swift           # UIColor named colors
├── String.swift          # String formatting utilities
├── Number.swift          # Number formatting (K/M suffixes)
├── URL.swift             # URL scheme manipulation
└── UIKit Extensions.swift # UIViewController & UIView helpers

Best Practices

Use named colors from UIColor extension for consistent theming
Apply .shorten() to all social media counts (likes, followers, etc.)
Use showAlert() for user-facing error messages
Apply makeRounded() in layoutSubviews() for circular views
Use URL scheme conversion for video streaming with caching

Get Started

Architecture

Features

Components

Colors Extension

Named Colors

Implementation

Usage

String Extension

Methods

Implementation

Usage Examples

Number Extension

Methods

Implementation

Usage Examples

URL Extension

Methods

Implementation

Usage Examples

UIKit Extensions

UIViewController Extension

Methods

Implementation

Usage Examples

UIView Extension

Methods

Implementation

Usage Examples

Extension Organization

Best Practices

Build docs developers (and LLMs) love

Get Started

Architecture

Features

Components

​Colors Extension

​Named Colors

​Implementation

​Usage

​String Extension

​Methods

​Implementation

​Usage Examples

​Number Extension

​Methods

​Implementation

​Usage Examples

​URL Extension

​Methods

​Implementation

​Usage Examples

​UIKit Extensions

​UIViewController Extension

​Methods

​Implementation

​Usage Examples

​UIView Extension

​Methods

​Implementation

​Usage Examples

​Extension Organization

​Best Practices

Build docs developers (and LLMs) love

Colors Extension

Named Colors

Implementation

Usage

String Extension

Methods

Implementation

Usage Examples

Number Extension

Methods

Implementation

Usage Examples

URL Extension

Methods

Implementation

Usage Examples

UIKit Extensions

UIViewController Extension

Methods

Implementation

Usage Examples

UIView Extension

Methods

Implementation

Usage Examples

Extension Organization

Best Practices