Encoding and Decoding in Swift | raywenderlich.com

In this tutorial, you’ll learn all about encoding and decoding in Swift, exploring the basics and advanced topics like custom dates and custom encoding.

This is a companion discussion topic for the original entry at https://www.raywenderlich.com/3418439-encoding-and-decoding-in-swift

Great article, thank you for sharing. But I seems found ambiguous syntax in Working With Deep JSON Hierarchies section. In encode function and following syntax:

giftContainer.encode(toy, forKey: .toy)

toy must be replaced to gift, because toy is global variable from outside Employee class instead gift is instance variable of Employee. Revised syntax:

giftContainer.encode(gift, forKey: .toy)

Thank you for the tutorial!
I found a typo in the section, “Working With Deep JSON Hierarchies”.

enum CodingKeys: CodingKey {
case name, id, gift
// 2
enum GiftKeys: CodingKey {
case toy
// 3
func encode(to encoder: Encoder) throws {
var container = encoder.container(keyedBy: CodingKeys.self)
try container.encode(name, forKey: .name)
try container.encode(id, forKey: .id)
// 4
var giftContainer = container
.nestedContainer(keyedBy: GiftKeys.self, forKey: .gift)
try giftContainer.encode(toy, forKey: .toy)

The last line: try giftContainer.encode(toy, forKey: .toy),
should be: try giftContainer.encode(favoriteToy, forKey: .toy).
The favoriteToy was mistyped to toy.

I think I also found a typo, in working with flat JSON hierarchies where it talks mapping the swift object “favoriteToy” to the JSON key “gift” it instead references the object “toy” down below.

I believe that

        try container.encode(toy.name, forKey: .gift)

should be

        try container.encode(favoriteToy.name, forKey: .gift)

@shogunkaramazov Great Article. I want to know how codable perform downcasting if possible. For example, In java

    id: 1,
    name: "MyName",

this above json convert into object like

class Employee {
    String id;
    String name;

If I decode network call which contains Int, but I use String to convert, it throws an error.
Is there any way that could happen?

Thanks for a really clear and helpful article. My only feedback would be could you add a pros and cons section vs the alternative? Ie JSONSerialization


@iambatman @sides @madebydouglas Thank you for the heads up - much appreciated! I have fixed all issues.

Awesome tutorial! I think there may be a problem with the download - I only get two files in a “codable” directory - starter and final. But you reference this: “Open Snake case vs camel case
I see no other projects/files and tried the download a few times. Is there a link missing, or are the files missing from the download, or am I just missing something else? Thanks.

@rbaker Really glad you like it. Each playground actually has multiple pages after all. Make sure the Project Navigator is visible in Xcode by going to View/Navigators/Show Project Navigator to see them. I hope this helps. Please let me know if you have any other questions or issues about the whole thing when you get a chance. Thank you! :]

Ha! How could I NOT have checked that! Indeed, my error. Thanks again, and thanks for the great job on this tutorial. Awesome that you covered more than jus the basic encode/decode.

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@rbaker Thank you for your very kind words and thoughts - much appreciated! They really do mean a lot to me! :]

This tutorial is more than six months old so questions are no longer supported at the moment for it. Thank you!