Decoding Nested JSON Elements (SwiftUI)

Question

I am trying to parse the JSON data below into the structs that are shown. I am having a helluva time trying to figure out how to get at the "nested" elements, such as elements "title:", "content:", and "excerpt:". Whenever the code runs, it barfs while parsing the nested elements.

I've looked at the Apple Developer stuff and reviewed the Playground here: https://developer.apple.com/documentation/foundation/archives_and_serialization/using_json_with_custom_types

I also tried using quicktype.io to create the data models from the sample JSON, however, in the header of the exported file from quicktype it has the line: "let blogItem = try? newJSONDecoder().decode(BlogItem.self, from: jsonData)", however, I get a compile error that jsonData is not recognized and I'm not able to find any reference to it.

struct BlogSection: Codable, Identifiable {
    var id: Int
    var slug: String
    var link: String
    var title: [BlogTitle]
    var content: [ContentData]
}

struct BlogTitle:  Codable, Equatable, Identifiable {
    var id: UUID
    var rendered: String
}

struct ContentData: Codable, Identifiable{
    var id: UUID
    var rendered: String

}

/**************** JSON Data ***************/
[
{
"id": 10960,
"date": "2019-10-02T01:00:07",
"date_gmt": "2019-10-02T05:00:07",
"guid": {
"rendered": "example.com/blog-template-copy-copy/"
},
"modified": "2019-09-20T07:08:41",
"modified_gmt": "2019-09-20T11:08:41",
"slug": "relationships-matter",
"status": "publish",
"type": "post",
"link": "example.com/relationships-matter/",
"title": {
"rendered": "Relationships Matter"
},
"content": {
"rendered": "<h1>Page content</h1>",
"protected": false
},
"excerpt": {
"rendered": "<p>By: Joe Schmoe<br />\nFirst Author",
"protected": false
},
"author": 57,
"featured_media": 10958,
"comment_status": "open",
"ping_status": "open",
"sticky": false,
"template": "",
"format": "standard",
"meta": [],
"categories": [
613
],
"tags": [],
"_links": {
"self": [
{
"href": "example.com/wp-json/wp/v2/posts/10960"
}
],
"collection": [
{
"href": "example.com/wp-json/wp/v2/posts"
}
],
"about": [
{
"href": "example.com/wp-json/wp/v2/types/post"
}
],
"author": [
{
"embeddable": true,
"href": "example.com/wp-json/wp/v2/users/57"
}
],
"replies": [
{
"embeddable": true,
"href": "example.com/wp-json/wp/v2/comments?post=10960"
}
],
"version-history": [
{
"count": 5,
"href": "example.com/wp-json/wp/v2/posts/10960/revisions"
}
],
"predecessor-version": [
{
"id": 10971,
"href": "example.com/wp-json/wp/v2/posts/10960/revisions/10971"
}
],
"wp:featuredmedia": [
{
"embeddable": true,
"href": "example.com/wp-json/wp/v2/media/10958"
}
],
"wp:attachment": [
{
"href": "example.com/wp-json/wp/v2/media?parent=10960"
}
],
"wp:term": [
{
"taxonomy": "category",
"embeddable": true,
"href": "example.com/wp-json/wp/v2/categories?post=10960"
},
{
"taxonomy": "post_tag",
"embeddable": true,
"href": "example.com/wp-json/wp/v2/tags?post=10960"
}
],
"curies": [
{
"name": "wp",
"href": "https://api.w.org/{rel}",
"templated": true
}
]
}
}
]

'

Sorin Lica · Accepted Answer · 2019-10-16 05:28:41Z

1

In the JSON you do not have arrays for title and content, so just remove the brackets

struct BlogSection: Codable, Identifiable {
    var id: Int
    var slug: String
    var link: String
    var title: BlogTitle
    var content: ContentData
}

struct BlogTitle:  Codable, Equatable, Identifiable {
    var id: UUID
    var rendered: String
}

struct ContentData: Codable, Identifiable{
    var id: UUID
    var rendered: String

}

answered Oct 16, 2019 at 5:28

Sorin Lica

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1 Comment

leromt Over a year ago

Sorin, the brackets were the problem. I spent hours trying to figure this out and I didn’t even think of that. Thanks for the help!

rubber duck · Accepted Answer · 2019-10-16 07:46:18Z

0

Title and Content are not Arrays in the json provided so should be declared as entities. Your BlogTitle and ContentData are declared as Identifiable and have a variable for id, but both do not have an id in the json provided, so you will get a decoding error because of that as well.

The error you are getting points to a completely different problem though. How is your jsonData declared?

answered Oct 16, 2019 at 7:46

rubber duck

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1 Comment

leromt Over a year ago

Thanks for the help, but it ended up being the array brackets. Sigh.

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