Accessing URL and Array from within a Block of JSON Data - ios

Question

Let's say I have JSON data structured in the following way:
{ "fruits" : {
"apple": {
"name": "Gala"
"color": "red",
"picture": "//juliandance.org/wp-content/uploads/2016/01/RedApple.jpg",
"noOfFruit": [1, 2]
}
}
How would I access the picture and noOfFruit array using the iOS version of Firebase? I want to make a table view with a cell that lists the apple's name, the color, a picture of the apple, and then lists the number of fruit. I get how to obtain the "color" and "name" values but how would I access the array and turn it into a string and the image so that it shows the image in the table view? Any help is appreciated!

Answer 1

For the array, it's really simple. Wherever you have your function that listenes for the firebase changes, I'll imagine that you have the info under the apple key stored in a variable like let apple
Then, you could cast the value of noOfFruit to an array, like the following:
let apple = // what you had before
guard let noOfFruit = apple["noOfFruit"] as? [Int] else {
return
}
//Here you have the array of ints called noOfFruit
For the image, theres several options out there. The first (and bad one) is to synchrounsly fetch the data of the url and set it to an image view as the following:
let url = URL(string: picture)
let data = try? Data(contentsOf: url!) //this may break due to force unwrapping, make sure it exists
imageView.image = UIImage(data: data!)
The thing with this approach is that it's NOT OK. It will block the main thread while its making the request and dowloading the image, leaving the app unresponsive.
The better approach would be to go fetch it asynchronously.There are several libraries that really help, such as AlamofireImage, but it can be done with barebones Foundation really easy. To do that, you should use URLSession class as the following:
guard let url = URL(string: picture) else {
return
}
URLSession.shared.dataTask(with: url) { data, response, error in
if let error = error {
print(error)
return
}
//Remember to do UI updates in the main thread
DispatchQueue.main.async {
self.myImageView.image = UIImage(data: data!)
}
}.resume()