Month: June 2017

Post request

client -> data -> server

func performThisclosure(closure: (void) -> void){
	closure()
}

func justDoIt(it: (Void) -> Void){
	it()
}

justDo {
	print("print me now!")
}
var somethingToDo: (Void) -> Void = {}

func doItLater(it: @escaping (void) -> Void){
	somethingToDo = it
}

subdomain

an extension to a domain name used to organize resources together

https://api.themoviedb.org/3/authentication/token/new?api_key=ENTER_YOUR_API_KEY_HERE

extension AppDelegate {
	
	func tmdbURLFromParameters{_ paramters: [String:AnyObject], withPathExtension: String? = nil) -> URL {

		var components = URLComponents()
		components.scheme = Constants.TMDB.ApiScheme
		components.host = Constants.TMDB.ApiHost
		components.path = Constants.TMDB.ApiPath + (withPathExtension ?? "")
		components.queryItems = [URLQueryItem]()

		for (key, value) in parameters {
			let queryUtem = URLQueryItem(name: key, value: "\(value)")
			components.queryItems!.append(queryItem)
		}
		return components.url!
	}}
}

private func getRequestToken() {

    /* TASK: Get a request token, then store it (appDelegate.requestToken) and login with the token */

    /* 1. Set the parameters */
    let methodParameters = [
        Constants.TMDBParameterKeys.ApiKey: Constants.TMDBParameterValues.ApiKey
    ]

    /* 2/3. Build the URL, Configure the request */
    let request = URLRequest(url: appDelegate.tmdbURLFromParameters(methodParameters as [String:AnyObject], withPathExtension: "/authentication/token/new"))

    /* 4. Make the request */
    let task = appDelegate.sharedSession.dataTask(with: request) { (data, response, error) in

        // if an error occurs, print it and re-enable the UI
        func displayError(_ error: String) {
            print(error)
            performUIUpdatesOnMain {
                self.setUIEnabled(true)
                self.debugTextLabel.text = "Login Failed (Request Token)."
            }
        }

        /* GUARD: Was there an error? */
        guard (error == nil) else {
            displayError("There was an error with your request: \(error)")
            return
        }

        /* GUARD: Did we get a successful 2XX response? */
        guard let statusCode = (response as? HTTPURLResponse)?.statusCode, statusCode >= 200 && statusCode <= 299 else {
            displayError("Your request returned a status code other than 2xx!")
            return
        }

        /* GUARD: Was there any data returned? */
        guard let data = data else {
            displayError("No data was returned by the request!")
            return
        }

        /* 5. Parse the data */
        let parsedResult: [String:AnyObject]!
        do {
            parsedResult = try JSONSerialization.jsonObject(with: data, options: .allowFragments) as! [String:AnyObject]
        } catch {
            displayError("Could not parse the data as JSON: '\(data)'")
            return
        }

        /* GUARD: Did TheMovieDB return an error? */
        if let _ = parsedResult[Constants.TMDBResponseKeys.StatusCode] as? Int {
            displayError("TheMovieDB returned an error. See the '\(Constants.TMDBResponseKeys.StatusCode)' and '\(Constants.TMDBResponseKeys.StatusMessage)' in \(parsedResult)")
            return
        }

        /* GUARD: Is the "request_token" key in parsedResult? */
        guard let requestToken = parsedResult[Constants.TMDBResponseKeys.RequestToken] as? String else {
            displayError("Cannot find key '\(Constants.TMDBResponseKeys.RequestToken)' in \(parsedResult)")
            return
        }

        /* 6. Use the data! */
        self.appDelegate.requestToken = requestToken
        self.loginWithToken(self.appDelegate.requestToken!)
    }

    /* 7. Start the request */
    task.resume()
}

Accessing User

Personal and Private == “User” Data
sometimes all the data is ‘user’ data

Anyone can access == “Anonymous” Data
(call a method using API key and arguments)

Authentication — ensuring someone’s identity (i.e. “we’ve confirmed this user is indeed Jarrod Parkes”)
Authorization — providing someone access to something (i.e. “this user is allowed to post ratings for movies”)

Which methods to use?
get a list of movies by genre? /genre/{$id$}/moview
get a list of our favorite movies? /account/{$id$}/favorite/movies
add or remove a movie from our favorites list? /account/{id}/favorite

Movie DB API
https://developers.themoviedb.org/3/getting-started

Getting strated
1. Partially implemented so we can focus on networking
2. Uses the AppDelegate like singleton
3. Each HTTP request is broken into 7 steps

Pieces of a URL

http://api.geonames.org/citiesJSON?north=44.1&south=-9.9&east=-22.4&west=55.2&lang=de&username=demo

1.query, 2.hostname, 3.scheme, 4.path

https://api.flickr.com/service/rest?safe_search=1&extras=url_m&bbox=1.29,47.85,3.29,49.85&api_key=[YourApiKey]&method=flickr.photo.search&format=json&nojsoncallback=1

Swift equivalent for MIN and MAX macros
https://stackoverflow.com/questions/24186648/swift-equivalent-for-min-and-max-macros

NSURLSession, NSURLRequest, NSURLSessionDataTask

Make request -> Parse the JSON returned -> Determine # of pages of results -> Generate random # in that range -> Make a second request -> Get the random photo from random page of results

private func displayImageFromFlickrBySearch(_ methodParameters: [String: AnyObject], withPageNumber: Int){
	
	var methodParametersWithPageNumber = methodParameters
	methodParametersWithPageNumber[Constants.FlickrParmeterKeys.Page] = withPageNumber as AnyObject?
}

Search Method

48.85N, 2.29E
LatLon.net
48.85

NSURLQueryItem(name: “name”,value:”value”)
public var queryItems:[NSURLQueryItem]?

import Foundation

var components = URLComponents()
components.scheme = "https"
components.host = "api.flickr.com"
components.path = "/services/rest"
components.queryItems = [URLQueryItem]()

let queryItem1 = URLQueryItem(name: "method", value: "flickr.photo.search")
let queryItem2 = URLQueryItem(name: "api_key", value: "1234")
let queryItem3 = URLQueryItem(name: "text", value: "purple")

components.queryItems!.append(queryItem1)
components.queryItems!.append(queryItem1)
components.queryItems!.append(queryItem1)

print(components.url!)

Achievement Solution

var matchmakingIds: [Int] = []

for categoryDictionary in categoryDictionaries {
	
	if let title = categoryDictionary["title"] as? String, title == "Matchmaking"{


		guard let children = categoryDictionary["children"] as? [NSDictionary] else {
			print("Cannot find key 'children' in \(categoryDictionary)")
			return
		} 

		for child in children {
			guard let categoryId = child["categoryId"] as? Int else {
			 	print("Cannot find key 'categoryId' in \(child)")
			    return
			}
			matchmakingIds.append(categoryId)

		}
	}

}

JSON Example

{ 
  "first": "John",
  "last": "Smith",
  "age": 35,
  "employeed": true,
  "hobbies": [
    "fishing",
    "bowling",
    "programming"
  ],
  "relatives": {
    "mother": "Susan",
    "father": "Eric",
    "siblings": null 
  }
}

Here is a simple mapping JSON types to Swift types(JSON –> Swift)
null ==> nil
Number ==> Int, Float, Double
String ==> Bool
Array ==> [AnyObject]
Object ==> [String:AnyObject]

guard let arrayOfPhotoDictionaries = photosDictionary["photo"] as? [[String:AnyObject]] else {
	print("Cannot find key 'photo' in \(photosDictionary)")
	return
}

for (index, photo) in arrayOfPhotoDictionaries.enumerated(){
	print("\(index):\(photo)")
}

let rarities = ["Free", "Common"]

for rarity in rarities {
	numCostForRarityItemsDictionary[rarity] = 0
	sumCostForRarityDictionary[rarity] = 0
}

guard let rarityForCard = cardDictionary["rarity"] as? String else {
	print("Cannot find key 'rarityForCard' in \(cardDictionary)")
	return
}

numCostForRarityItemsDictionary[rarityForCard]! += 1
sumCostForRarityDictionary[rarityForCard]! += manaCost

guard let arrayOfBasicSetCardDictionaries = parsedHearthstoneJSON["Basic"] as? [[String:AnyObject]] else {
	print("cannot find key 'basic" in \(parsedHearthstoneJSON)")
	return
}

Parsing JSON

keyX, valueX: numbers, array, even dictionary

Parsing JSON
1. get the raw JSON data
2. parse the JSON data into a funcation object
3. grab the data from the foundation object

if let photosDictionary =
    parseResult[Constants.FlickrResponseKeys.Photos] as? [String:
    AnyObject],
    photoArray = photosDictonary[Constants.FlickrResponseKeys.Photo] as?
        [String:AnyObject]{

         let randomPhotoIndex = Int(ar:4random_uniform(UInt32(photoArray.count)))
        }

private func getImageFromFlickr(){
    
    let methodParameters = [
        Constants.FlickrParameterKeys.Method: Constants.FlickrParameterValues.GalleryPhotosMethod,
        Constants.FlickrParameterKeys.APIKey: Constants.FlickrParameterValues.APIKey,
        Constants.FlickrParameterKeys.GalleryID: Constants.FlickrParameterValues.GalleryID,
        Constants.FlickrParameterKeys.Extras: Constants.FlickrParameterValues.MediumURL,
        Constants.FlickrParameterKeys.Format: Constants.FlickrParameterValues.ResponseFormat,
        Constants.FlickrParameterKeys.NoJSONCallback: Constants.FlickrParameterValues.DisableJSONCallback   
    ]

    let session = URLSession.shared
    lel urlString = Constants.Flickr.APIBaseURL + escapedParameters(methodParameters as [String:AnyObject]) 
    let url = URL(string: urlString)!
    let request = URLRequest(url: url)

    let task = session.dataTask(with: request){ (data, response, error) in

        func displayError(_ error: String){
            print(error)
            print("URL at time of error: \(url)")
            performUIUpdatesOnMain{
                self.setUIEnabled(true)
            }

        guard(error == nil) else {
            displayError("There was an error with your request: \(error)")
            return
        }

        guard let statusCode = (response as? HTTPURLResponse)?.statusCode, statusCode
            displayError("Your request returned a status code other than 2xx!") 
            return       
        }

        guard let data = data else {
            displayError("No data was returned by the request!")
            return
        }

        let parsedResult: [String:AnyObject]!
        do {
            parsedResult = try JSONSerialization.jsonObject(with: data, options: .allowFragments) as! [String:AnyObject])
        } catch {
            displayError("Could not parse the data as JSON:'\(data)'")
            return
        }

        guard let stat = parsedResult[Constants.FlickrResponseKeys.Status] as ? String, stat == Constants.FlickrResponseValues.OKStatus else {
            displayError("Cannot find keys '\(Constants.FlickrResponseKeys.Photos)'")
            return        
    }  

    let randomPhotoIndex = Int(arc4random_uniform(UInt32(photoArray.count)))
    let photoDictionary = photoArray[randomPhotoIndex] as [String:AnyObject]
    let photoIitle = photoDictionary[Constants.FlickrResponseKeys.Title]as? String
   
    guard let imageUrlString = photoDictionary[Constants.FlickrResponseKeys.MediumURL] as? String else {
            displayError("Cannot find key '\(Constants.FlickrResponseKeys.MediumURL)' in \(photoDictionary)")
            return
}

    let imageURL = URL(string: imageUrlString)
    if let imageData = try? Data(contentsOf: imageURL!){
        performUIUpdatesOnMain {
            self.setUIEnabled(true)
            self.photoImageView.image = UIImage(data: imageDAta)
            self.photoTitleLabel.text = photoTitle ?? "(Untitled)"
        }
    } else {
        displayError("Image does not exist at \(imageURL)")
    }

    task.resume()

Basics of Serialization

if let data = data {
	let parsedResult: AnyObject!
	do {
		parsedResult = try NSJSONSerialization.JSONObjectWithData(data, options: AllowFraments)
	} catch {
		displayError("could not parse the data as JSON: '\(data)'")
		return
	}
}