URLSession (HTTP GET/PUT/POST) init? and dictionaryRepresentation

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

Failable Initializers

Example Dictionary:

let workingDictionary = ["nameKey" : "Derek", "ageKey": 28, "favMovieKey" : "Zoolander"]
let brokenDictionary = ["nameKey" : "Steve", "ageKey": 2]

PART 1

1. Make a person class with name, age, and favoriteMovie properties
2. init the class with a dictionary of type string:anyobject.
3. Test this to make sure that it works

PART 2

1. Read about Failable Initializers
2. Use a guard statement to handle missing dictionary values
3. If a value is missing, don't init the person and instead return nil

♦ Black Diamond

Open your Journal project from yesterday. Create a function that will convert your Entry objects into dictionaries. Use this to encode all of the Entry objects stored in your sharedInstance as dictionaries, then print the result.

Hint

Solution

Guided Project

StudentPUTAPI Part Two (PUT/POST)

StudentPUTAPI is a simple student list API that lets students practice using PUT and GET with a REST API.

Project

• Post Part Two

  Post is a simple global messaging service. Students will review MVC principles and work with NSURLSession, JSON parsing, and closures to build an app that lists and submits posts to a global feed.

  ReadMe

Mastery Review