Codable (Decoder) - Introduction

Objectives

• You will be able to identify and use closure syntax to work with network requests and other block based APIs
• You will be able to identify, describe, and use documentation to interact with REST APIs
• You will be able to use URLSession to download and serialize network data

Required Preclass Resources

• A Short Practical Guide to Closures
• Gosh Darn Block Syntax
• Higher Order Functions - Map, Filter, Reduce
• A Beginner's Guide to HTTP and REST

  Understand HTTP requests, URLs, and the HTTP Verbs (GET, PUT, DELETE, POST). Do not build the Example Application.

• What's New in Foundation Networking

  WWDC 2014 Video

• Ray Wenderlich URLSession Tutorial
• About the URL Loading System

  Apple's documentation about the URL Loading System. Read as much as you can.

Lesson Video

Video Challenges

• Sort the Array

  Using the Playground used in the Group Demo for this objective, sort the array of people by age in ascending order.

  Map an array of ages and sort that array in descending order.

• App Icon
  • Create an URLSessionDownloadTask to get poster art
  • Display the album art on the View Controller

Stretch Problem

Closures

1. Use filter to create an array that contains all the numbers that are multiples of 3 from the array [11,23,43,44,59,43,88,92,58,11,13,14,15]. Print your result
2. Find the largest number from the previous number array and then print it. Use reduce to solve. Print your result.
3. Join all the string objects in ["I", "Love", "Dev Mountain"] into one string using reduce. Make sure spaces are in between each string. Print your result.
♦ Black Diamond
In one line convert [["Mama": "too cold", "Papa": "too hot", "Baby": "just right"]] into an array with only one element that contains a string describing Mama, Papa, and Baby bear's porridge temperature. FlatMap, reduce, and anonymous closure arguments will be your friend.
Hint
Solution

Guided Project

Deck Of One Card

DeckOfOneCard lets students practice using closure syntax, network API documentation, and making network calls using URLSession.

Project

• Representative

  Students will build an app to get the representives (law makers) in a user-requested state to practice asyncronous network requests, working with JSON data, closures, and intermediate table views.

  ReadMe

Mastery Review