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iOS Build a Playlist Browser with Swift Building the Music Library and Playlist Models Creating UIImageView instances

Pedro Laplaza
Pedro Laplaza
1,960 Points
Posted by Pedro Laplaza
Pedro Laplaza
1,960 Points

Having trouble with the task Not being able to solve it

I am not being able to solve the problem, something seems to be missing.

Here is what i am asked to do: In our Treehouse model struct below we have a property named friends. It is a dictionary that holds information about our friends including their profile pictures. In the ViewController class, using the key profilePicture, retrieve the image name as a string from the dictionary and assign it to a constant named profileImageName. I’ve already created an instance of the Treehouse struct and stored a reference to the friends library in a constant named friends for you to use.

Once you have the image name, create an instance of UIImage using the image name and store it in a constant called profilePicture.

And here the code give to me:

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        let friends = Treehouse().friends
    }
}

// Treehouse.swift
struct Treehouse {
    let friends = [
        "firstName": "Susan",
        "lastName": "Olson",
        "profilePicture": "susan_profile.png"
    ]
}

So i created a new struct to handle the data and return them as strings and this is how my files look now.

// Treehouse.swift
struct Treehouse {
    let friends = [
        "firstName": "Susan",
        "lastName": "Olson",
        "profilePicture": "susan_profile.png"
    ]
}

struct Information {

    var firstName: String?
    var lastName: String?
    var profilePicture:String?

    init(){
        let friendsList = Treehouse().friends
        let treehouseFriends = friendsList

        firstName = treehouseFriends["firstName"] as String!
        lastName = treehouseFriends["lastName"] as String!
        profilePicture = treehouseFriends["profilePicture"] as String!
    }
}

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        let friends = Treehouse().friends
        let information = Information()
        let profileImageName = information.profilePicture
    }
}

And i get an error saying " Bummer! Make sure you assign the image to a constant named profilePicture and check your syntax." If i change my constant name to profilePicture i get the same error but with profileImageName

I am pretty sure this is not the best way to solve it, but it works on the playground

Can someone help me here please?

3 Answers

Steve Hunter
Steve Hunter
57,712 Points

Hi Pedro,

You need to add two lines to the challenge.

First, you access the friends dictionary with the key profilePicture to bring back the image file name and store that in the constant, profileImageName (remember to unwrap this as you're accessing a dictionary). You then use the UIImage method named: to generate the image from the filename and store that in the profilePicture constant: 

        let friends = Treehouse().friends
        let profileImageName = friends["profilePicture"] as String!
        let profilePicture = UIImage(named: profileImageName)

I hope that makes sense.

Steve.

Steve Hunter
Steve Hunter
57,712 Points

Your final code looks like:

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        let friends = Treehouse().friends

        //Add your code below
        let friends = Treehouse().friends
        let profileImageName = friends["profilePicture"] as String!
        let profilePicture = UIImage(named: profileImageName)
    }
}

There's no changes to the other file, it is all in viewDidLoad().

Pedro Laplaza
Pedro Laplaza
1,960 Points
Pedro Laplaza
Pedro Laplaza
1,960 Points

wow, i really went the other way around, i thought that should be part of the struct and not the viewController Thanks man If you can help me a little more, do you know why when i run this on a playground i get "nil" on the "let profilePicture"?

Steve Hunter
Steve Hunter
57,712 Points

Is that your code or the lines I posted? I'm just starting a playground ...

Steve Hunter
Steve Hunter
57,712 Points

I get an error in the playground about not using the profilePicture constant - that's understandable. As soon as I use profilePicture, that goes away.

Given that the file, susan_profile.png, doesn't exist, we're bound to come up with an error somewhere.

What errors are you getting?

Pedro Laplaza
Pedro Laplaza
1,960 Points
Pedro Laplaza
Pedro Laplaza
1,960 Points

No errors, just "nil" on the last line, but as you said, this might be because i am calling a UIImage element that i dont actually have

This is my playground

import UIKit

struct Treehouse {
    let friends = [
        "firstName": "Susan",
        "lastName": "Olson",
        "profilePicture": "susan_profile.png"
    ]
}

let friends = Treehouse().friends
let profileImageName = friends["profilePicture"] as String!
let profilePicture = UIImage(named: profileImageName)

Thanks for your help again man

Steve Hunter
Steve Hunter
57,712 Points

Yes, that's because you're asking for a file that doesn't exist. Kindly, the compiler throws a nil rather than crashing dramatically! ;-)