Lecture: Introduction to iOS App Development

Topics Covered

• Overview of Swift and writing a basic iOS app
• Key concepts: UIKit, MVC
• Creating views using storyboards
• Outlets and actions in Xcode
• Segues for transitioning between views
• Step-by-step guide to setting up a project in Xcode

UIKit and MVC Pattern

UIKit

• Framework from Apple for creating user interfaces
• Contains classes, methods, functions for UI elements like tables, images, buttons

MVC (Model-View-Controller)

• Model: Represents data, acts as a data structure with no display logic
• View: Presents data on the screen
• Controller: Facilitates interaction between model and view; contains the majority of the code

Basic iOS App: Table View Example

Key UI Component: Table View

• Used for lists (e.g., Contacts app, Twitter feed)
• Simple and essential for many iOS applications

Setting Up Xcode Project

Initial Steps

• Create a new Xcode Project
• Select iOS and Single View App
• Name the product (e.g., Pokedex), select Swift and Storyboard for language and UI
• Save the project and optionally create a Git repository

Xcode Generated Files

• AppDelegate.swift: Entry point for the app, manages app lifecycle
• ViewController.swift: Basic template for screen logic
• Main.storyboard: Visual editor for UI design
• Assets.xcassets: Asset catalog for images
• LaunchScreen.storyboard: Initial loading screen
• Info.plist: Configuration file

UI Development with Storyboards

Using Storyboards

• Drag-and-drop interface for creating UI elements
• Outlets: Connect UI elements to code
• Actions: Link UI element events to code

Creating Table View

• Replace initial view with a UITableViewController
• Setup storyboard to link to custom ViewController class
• Define data model (Pokemon struct)
• Populate table view with data from model

Adding Navigation

Navigation Controller

• Adds a title bar and enables navigation between views
• Embed initial view controller in a navigation controller

Detail View Creation

• Create a second view controller on storyboard for detail display
• Add UI elements like labels for data display
• Use segues for transitioning between views

Implementing Segues and Passing Data

• Define segue identifiers
• Override prepareForSegue to pass data between view controllers
• Use IBAction to manage UI element events

Formatting Data

• Use String(format:) for formatting strings (e.g., leading zeros)

Running the App

• Test the app on the iOS simulator
• Verify UI interactions and data passing between view controllers

Summary

• Covered basic setup and UI creation for iOS apps using Xcode
• Implemented navigation and data display for a Pokedex app
• Future steps include loading data dynamically from the internet