Human class in Swift, just for fun

Human.swift

//: Playground - noun: a place where people can play

import UIKit
import PlaygroundSupport

//PlaygroundPage.current.needsIndefiniteExecution = true

enum PhotoError: Error {
    case NoURL
    case BadImageData
}

class Human: CustomStringConvertible {
    private(set) var father: Human?
    private(set) var mother: Human?
    var fullName: String?
    var bornIn: String?
    var bornAt: Date?
    var photoUrl: URL?
    
    var description: String {
        if let name = self.fullName {
            return ("\(name)")
        }
        else {
            return ("No name")
        }
    }
    
    init(name: String) {
        fullName = name
    }
    
    init(name: String, fatherName: String, motherName: String) {
        fullName = name;
        father = Human(name: fatherName)
        mother = Human(name: motherName)
    }
    
    // Async version to get the image from photoUrl
    func photo(completionHandler: @escaping (UIImage?, NSError?) -> Void) {
        
        let session = URLSession.shared
        let dataTask = session.dataTask(with: self.photoUrl!) {
            (data, resp, err) in
            
            if let imgData = data {
                let image = UIImage(data: imgData)
                completionHandler(image, nil)
            }
            else {
                completionHandler(nil, err as NSError?)
            }
        }
        dataTask.resume()
    }
    
    func photo() throws -> UIImage {
        guard let url = self.photoUrl else {
            throw PhotoError.NoURL
        }

        let imageData = try Data(contentsOf: url)
        
        guard let image = UIImage(data: imageData) else {
            throw PhotoError.BadImageData
        }
        
        return image
    }
    
    func greet() -> String {
        
        let formatter = DateFormatter()
        formatter.dateFormat = "dd MMMM yyyy hh:mm"
        let dateString = formatter.string(from: self.bornAt!)
        
        let greeting = "<span>Hello world!<br/>I'm <b>\(self.fullName!)</b><br/>Born in <b>\(self.bornIn!)</b> on <b>\(dateString)</b><br/>My parents are <b>\(self.father!)</b> and <b>\(self.mother!)</b></span>"
        return greeting
    }
    
    func formattedGreet() -> NSAttributedString {
        let greetingString = greet() + "<style>span{font-family: 'Avenir-Roman';font-size: 12px;}</style>"
        let greetingData = greetingString.data(using: String.Encoding.utf16)

        let attrStr = try! NSMutableAttributedString(data: greetingData!,
                                              options: [ NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType],
                                              documentAttributes: nil)
        
        return attrStr
    }
    
    func describeNameMeaning() -> NSAttributedString {
        
        //assumed there's a web API to get the name's meaning :)
        
        let meaning = "<span>My name means <b>\"My dream (is to be) the bestower of long life\"</b>.<br/><b>Alora</b> is of African origin that means <b>\"My dream\"</b>. <b>Jivanka</b> is intentionally shorted from the word of <b>\"Jivantika\"</b> which is derived from a Sanskrit word meaning <b>\"bestower of long life\"</b>. \"Alora\" is also derived from \"Elora\" which means <b>\"God is light\"</b> in Hebrew, or simply <b>\"Light\"</b> in Greek. Hence, my parents hope that someday I'll be the light and giving life to anything I'm involved in. <br/>Both Alora and Jivanka are the result of my mom's long research.<br/>My father thinks it's an awesome name because it is combination of <b>\"A\" + \"LoRa\"</b>. He always wants my name to start with \"A\". <b>\"LoRa\"</b> is a unique (and awesome) modulation technology that enable low data rate communications to be made over long distances. He is intensively doing reseach about LoRa implementation and made a few products out of it.</span><style>span{font-family: 'Avenir-Roman';font-size: 12px;}</style>"
        let meaningData = meaning.data(using: String.Encoding.utf16)
        
        let attrStr = try! NSMutableAttributedString(data: meaningData!,
                                                     options: [ NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType],
                                                     documentAttributes: nil)
        
        return attrStr
    }
}