yattee/Model/Applications/PipedAPI.swift
Toni Förster 6eba2a45c8
Conditional proxying
I added a new feature. When instances are not proxied, Yattee first checks the URL to make sure it is not a restricted video. Usually, music videos and sports content can only be played back by the same IP address that requested the URL in the first place. That is why some videos do not play when the proxy is disabled.

This approach has multiple advantages. First and foremost, It reduced the load on Invidious/Piped instances, since users can now directly access the videos without going through the instance, which might be severely bandwidth limited. Secondly, users don't need to manually turn on the proxy when they want to watch IP address bound content, since Yattee automatically proxies such content.

Furthermore, adding the proxy option allows mitigating some severe playback issues with invidious instances. Invidious by default returns proxied URLs for videos, and due to some bug in the Invidious proxy, scrubbing or continuing playback at a random timestamp can lead to severe wait times for the users.

This should fix numerous playback issues: #666, #626, #590, #585, #498, #457, #400
2024-05-16 19:35:31 +02:00

831 lines
29 KiB
Swift

import Alamofire
import AVFoundation
import Foundation
import Siesta
import SwiftyJSON
final class PipedAPI: Service, ObservableObject, VideosAPI {
static var disallowedVideoCodecs = ["av01"]
static var authorizedEndpoints = ["subscriptions", "subscribe", "unsubscribe", "user/playlists"]
static var contentItemsKeys = ["items", "content", "relatedStreams"]
@Published var account: Account!
static func withAnonymousAccountForInstanceURL(_ url: URL) -> PipedAPI {
.init(account: Instance(app: .piped, apiURLString: url.absoluteString).anonymousAccount)
}
init(account: Account? = nil) {
super.init()
guard account != nil else {
return
}
setAccount(account!)
}
func setAccount(_ account: Account) {
self.account = account
configure()
}
func configure() {
invalidateConfiguration()
configure {
$0.pipeline[.parsing].add(SwiftyJSONTransformer, contentTypes: ["*/json"])
}
configure(whenURLMatches: { url in self.needsAuthorization(url) }) {
$0.headers["Authorization"] = self.account.token
}
configureTransformer(pathPattern("channel/*")) { (content: Entity<JSON>) -> ChannelPage in
let nextPage = content.json.dictionaryValue["nextpage"]?.string
let channel = self.extractChannel(from: content.json)
return ChannelPage(
results: self.extractContentItems(from: self.contentItemsDictionary(from: content.json)),
channel: channel,
nextPage: nextPage,
last: nextPage.isNil
)
}
configureTransformer(pathPattern("/nextpage/channel/*")) { (content: Entity<JSON>) -> ChannelPage in
let nextPage = content.json.dictionaryValue["nextpage"]?.string
return ChannelPage(
results: self.extractContentItems(from: self.contentItemsDictionary(from: content.json)),
channel: self.extractChannel(from: content.json),
nextPage: nextPage,
last: nextPage.isNil
)
}
configureTransformer(pathPattern("channels/tabs*")) { (content: Entity<JSON>) -> [ContentItem] in
(content.json.dictionaryValue["content"]?.arrayValue ?? []).compactMap { self.extractContentItem(from: $0) }
}
configureTransformer(pathPattern("c/*")) { (content: Entity<JSON>) -> Channel? in
self.extractChannel(from: content.json)
}
configureTransformer(pathPattern("user/*")) { (content: Entity<JSON>) -> Channel? in
self.extractChannel(from: content.json)
}
configureTransformer(pathPattern("playlists/*")) { (content: Entity<JSON>) -> ChannelPlaylist? in
self.extractChannelPlaylist(from: content.json)
}
configureTransformer(pathPattern("user/playlists/create")) { (_: Entity<JSON>) in }
configureTransformer(pathPattern("user/playlists/delete")) { (_: Entity<JSON>) in }
configureTransformer(pathPattern("user/playlists/add")) { (_: Entity<JSON>) in }
configureTransformer(pathPattern("user/playlists/remove")) { (_: Entity<JSON>) in }
configureTransformer(pathPattern("streams/*")) { (content: Entity<JSON>) -> Video? in
self.extractVideo(from: content.json)
}
configureTransformer(pathPattern("trending")) { (content: Entity<JSON>) -> [Video] in
self.extractVideos(from: content.json)
}
configureTransformer(pathPattern("search")) { (content: Entity<JSON>) -> SearchPage in
let nextPage = content.json.dictionaryValue["nextpage"]?.string
return SearchPage(
results: self.extractContentItems(from: content.json.dictionaryValue["items"]!),
nextPage: nextPage,
last: nextPage == "null"
)
}
configureTransformer(pathPattern("suggestions")) { (content: Entity<JSON>) -> [String] in
content.json.arrayValue.map(String.init)
}
configureTransformer(pathPattern("subscriptions")) { (content: Entity<JSON>) -> [Channel] in
content.json.arrayValue.compactMap { self.extractChannel(from: $0) }
}
configureTransformer(pathPattern("feed")) { (content: Entity<JSON>) -> [Video] in
content.json.arrayValue.compactMap { self.extractVideo(from: $0) }
}
configureTransformer(pathPattern("comments/*")) { (content: Entity<JSON>?) -> CommentsPage in
guard let details = content?.json.dictionaryValue else {
return CommentsPage(comments: [], nextPage: nil, disabled: true)
}
let comments = details["comments"]?.arrayValue.compactMap { self.extractComment(from: $0) } ?? []
let nextPage = details["nextpage"]?.string
let disabled = details["disabled"]?.bool ?? false
return CommentsPage(comments: comments, nextPage: nextPage, disabled: disabled)
}
configureTransformer(pathPattern("user/playlists")) { (content: Entity<JSON>) -> [Playlist] in
content.json.arrayValue.compactMap { self.extractUserPlaylist(from: $0) }
}
if account.token.isNil || account.token!.isEmpty {
updateToken()
} else {
FeedModel.shared.onAccountChange()
SubscribedChannelsModel.shared.onAccountChange()
PlaylistsModel.shared.onAccountChange()
}
}
func needsAuthorization(_ url: URL) -> Bool {
Self.authorizedEndpoints.contains { url.absoluteString.contains($0) }
}
func updateToken() {
let (username, password) = AccountsModel.getCredentials(account)
guard !account.anonymous,
let username,
let password
else {
return
}
AF.request(
login.url,
method: .post,
parameters: ["username": username, "password": password],
encoding: JSONEncoding.default
)
.responseDecodable(of: JSON.self) { [weak self] response in
guard let self else {
return
}
switch response.result {
case let .success(value):
let json = JSON(value)
let token = json.dictionaryValue["token"]?.string ?? ""
if let error = json.dictionaryValue["error"]?.string {
NavigationModel.shared.presentAlert(
title: "Account Error",
message: error
)
} else if !token.isEmpty {
AccountsModel.setToken(self.account, token)
self.objectWillChange.send()
} else {
NavigationModel.shared.presentAlert(
title: "Account Error",
message: "Could not update your token."
)
}
self.configure()
case let .failure(error):
NavigationModel.shared.presentAlert(
title: "Account Error",
message: error.localizedDescription
)
}
}
}
var login: Resource {
resource(baseURL: account.url, path: "login")
}
func channel(_ id: String, contentType: Channel.ContentType, data: String?, page: String?) -> Resource {
let path = page.isNil ? "channel" : "nextpage/channel"
var channel: Siesta.Resource
if contentType == .videos || data.isNil {
channel = resource(baseURL: account.url, path: "\(path)/\(id)")
} else {
channel = resource(baseURL: account.url, path: "channels/tabs")
.withParam("data", data)
}
if let page, !page.isEmpty {
channel = channel.withParam("nextpage", page)
}
return channel
}
func channelByName(_ name: String) -> Resource? {
resource(baseURL: account.url, path: "c/\(name)")
}
func channelByUsername(_ username: String) -> Resource? {
resource(baseURL: account.url, path: "user/\(username)")
}
func channelVideos(_ id: String) -> Resource {
channel(id, contentType: .videos)
}
func channelPlaylist(_ id: String) -> Resource? {
resource(baseURL: account.url, path: "playlists/\(id)")
}
func trending(country: Country, category _: TrendingCategory? = nil) -> Resource {
resource(baseURL: account.instance.apiURL, path: "trending")
.withParam("region", country.rawValue)
}
func search(_ query: SearchQuery, page: String?) -> Resource {
let path = page.isNil ? "search" : "nextpage/search"
let resource = resource(baseURL: account.instance.apiURL, path: path)
.withParam("q", query.query)
.withParam("filter", "all")
if page.isNil {
return resource
}
return resource.withParam("nextpage", page)
}
func searchSuggestions(query: String) -> Resource {
resource(baseURL: account.instance.apiURL, path: "suggestions")
.withParam("query", query.lowercased())
}
func video(_ id: Video.ID) -> Resource {
resource(baseURL: account.instance.apiURL, path: "streams/\(id)")
}
var signedIn: Bool {
guard let account else {
return false
}
return !account.anonymous && !(account.token?.isEmpty ?? true)
}
var subscriptions: Resource? {
resource(baseURL: account.instance.apiURL, path: "subscriptions")
}
func feed(_: Int?) -> Resource? {
resource(baseURL: account.instance.apiURL, path: "feed")
.withParam("authToken", account.token)
}
var home: Resource? { nil }
var popular: Resource? { nil }
var playlists: Resource? {
resource(baseURL: account.instance.apiURL, path: "user/playlists")
}
func subscribe(_ channelID: String, onCompletion: @escaping () -> Void = {}) {
resource(baseURL: account.instance.apiURL, path: "subscribe")
.request(.post, json: ["channelId": channelID])
.onCompletion { _ in onCompletion() }
}
func unsubscribe(_ channelID: String, onCompletion: @escaping () -> Void = {}) {
resource(baseURL: account.instance.apiURL, path: "unsubscribe")
.request(.post, json: ["channelId": channelID])
.onCompletion { _ in onCompletion() }
}
func playlist(_ id: String) -> Resource? {
channelPlaylist(id)
}
func playlistVideo(_: String, _: String) -> Resource? { nil }
func playlistVideos(_: String) -> Resource? { nil }
func addVideoToPlaylist(
_ videoID: String,
_ playlistID: String,
onFailure: @escaping (RequestError) -> Void = { _ in },
onSuccess: @escaping () -> Void = {}
) {
let resource = resource(baseURL: account.instance.apiURL, path: "user/playlists/add")
let body = ["videoId": videoID, "playlistId": playlistID]
resource
.request(.post, json: body)
.onSuccess { _ in onSuccess() }
.onFailure(onFailure)
}
func removeVideoFromPlaylist(
_ index: String,
_ playlistID: String,
onFailure: @escaping (RequestError) -> Void,
onSuccess: @escaping () -> Void
) {
let resource = resource(baseURL: account.instance.apiURL, path: "user/playlists/remove")
let body: [String: Any] = ["index": Int(index)!, "playlistId": playlistID]
resource
.request(.post, json: body)
.onSuccess { _ in onSuccess() }
.onFailure(onFailure)
}
func playlistForm(
_ name: String,
_: String,
playlist: Playlist?,
onFailure: @escaping (RequestError) -> Void,
onSuccess: @escaping (Playlist?) -> Void
) {
let body = ["name": name]
let resource = playlist.isNil ? resource(baseURL: account.instance.apiURL, path: "user/playlists/create") : nil
resource?
.request(.post, json: body)
.onSuccess { response in
if let modifiedPlaylist: Playlist = response.typedContent() {
onSuccess(modifiedPlaylist)
} else {
onSuccess(nil)
}
}
.onFailure(onFailure)
}
func deletePlaylist(
_ playlist: Playlist,
onFailure: @escaping (RequestError) -> Void,
onSuccess: @escaping () -> Void
) {
let resource = resource(baseURL: account.instance.apiURL, path: "user/playlists/delete")
let body = ["playlistId": playlist.id]
resource
.request(.post, json: body)
.onSuccess { _ in onSuccess() }
.onFailure(onFailure)
}
func comments(_ id: Video.ID, page: String?) -> Resource? {
let path = page.isNil ? "comments/\(id)" : "nextpage/comments/\(id)"
let resource = resource(baseURL: account.url, path: path)
if page.isNil {
return resource
}
return resource.withParam("nextpage", page)
}
private func pathPattern(_ path: String) -> String {
"**\(path)"
}
private func extractContentItem(from content: JSON) -> ContentItem? {
let details = content.dictionaryValue
let contentType: ContentItem.ContentType
if let url = details["url"]?.string {
if url.contains("/playlist") {
contentType = .playlist
} else if url.contains("/channel") {
contentType = .channel
} else {
contentType = .video
}
} else {
contentType = .video
}
switch contentType {
case .video:
if let video = extractVideo(from: content) {
return ContentItem(video: video)
}
case .playlist:
if let playlist = extractChannelPlaylist(from: content) {
return ContentItem(playlist: playlist)
}
case .channel:
if let channel = extractChannel(from: content) {
return ContentItem(channel: channel)
}
default:
return nil
}
return nil
}
private func extractContentItems(from content: JSON) -> [ContentItem] {
content.arrayValue.compactMap { extractContentItem(from: $0) }
}
private func extractChannel(from content: JSON) -> Channel? {
let attributes = content.dictionaryValue
guard let id = attributes["id"]?.string ??
(attributes["url"] ?? attributes["uploaderUrl"])?.string?.components(separatedBy: "/").last
else {
return nil
}
let subscriptionsCount = attributes["subscriberCount"]?.int ?? attributes["subscribers"]?.int
var videos = [Video]()
if let relatedStreams = attributes["relatedStreams"] {
videos = extractVideos(from: relatedStreams)
}
let name = attributes["name"]?.string ??
attributes["uploaderName"]?.string ??
attributes["uploader"]?.string ?? ""
let thumbnailURL = attributes["avatarUrl"]?.url ??
attributes["uploaderAvatar"]?.url ??
attributes["avatar"]?.url ??
attributes["thumbnail"]?.url
let tabs = attributes["tabs"]?.arrayValue.compactMap { tab in
let name = tab["name"].string
let data = tab["data"].string
if let name, let data, let type = Channel.ContentType(rawValue: name) {
return Channel.Tab(contentType: type, data: data)
}
return nil
} ?? [Channel.Tab]()
return Channel(
app: .piped,
id: id,
name: name,
bannerURL: attributes["bannerUrl"]?.url,
thumbnailURL: thumbnailURL,
subscriptionsCount: subscriptionsCount,
verified: attributes["verified"]?.bool,
videos: videos,
tabs: tabs
)
}
func extractChannelPlaylist(from json: JSON) -> ChannelPlaylist? {
let details = json.dictionaryValue
let id = details["url"]?.stringValue.components(separatedBy: "?list=").last
let thumbnailURL = details["thumbnail"]?.url ?? details["thumbnailUrl"]?.url
var videos = [Video]()
if let relatedStreams = details["relatedStreams"] {
videos = extractVideos(from: relatedStreams)
}
return ChannelPlaylist(
id: id ?? UUID().uuidString,
title: details["name"]?.string ?? "",
thumbnailURL: thumbnailURL,
channel: extractChannel(from: json),
videos: videos,
videosCount: details["videos"]?.int
)
}
static func nonProxiedAsset(asset: AVURLAsset, completion: @escaping (AVURLAsset?) -> Void) {
guard var urlComponents = URLComponents(url: asset.url, resolvingAgainstBaseURL: false) else {
completion(asset)
return
}
guard let hostItem = urlComponents.queryItems?.first(where: { $0.name == "host" }),
let hostValue = hostItem.value
else {
completion(asset)
return
}
urlComponents.host = hostValue
guard let newUrl = urlComponents.url else {
completion(asset)
return
}
completion(AVURLAsset(url: newUrl))
}
// Overload used for hlsURLS
static func nonProxiedAsset(url: URL, completion: @escaping (AVURLAsset?) -> Void) {
let asset = AVURLAsset(url: url)
nonProxiedAsset(asset: asset, completion: completion)
}
private func extractVideo(from content: JSON) -> Video? {
let details = content.dictionaryValue
if let url = details["url"]?.string {
guard url.contains("/watch") else {
return nil
}
}
let channelId = details["uploaderUrl"]?.string?.components(separatedBy: "/").last ?? "unknown"
let thumbnails: [Thumbnail] = Thumbnail.Quality.allCases.compactMap {
if let url = buildThumbnailURL(from: content, quality: $0) {
return Thumbnail(url: url, quality: $0)
}
return nil
}
let author = details["uploaderName"]?.string ?? details["uploader"]?.string ?? ""
let authorThumbnailURL = details["avatarUrl"]?.url ?? details["uploaderAvatar"]?.url ?? details["avatar"]?.url
let subscriptionsCount = details["uploaderSubscriberCount"]?.int
let uploaded = details["uploaded"]?.double
var published = (uploaded.isNil || uploaded == -1) ? nil : (uploaded! / 1000).formattedAsRelativeTime()
var publishedAt: Date?
let dateFormatter = ISO8601DateFormatter()
dateFormatter.formatOptions = [.withInternetDateTime]
if published.isNil,
let date = details["uploadDate"]?.string,
let formattedDate = dateFormatter.date(from: date)
{
publishedAt = formattedDate
} else {
published = (details["uploadedDate"] ?? details["uploadDate"])?.string ?? ""
}
let live = details["livestream"]?.bool ?? (details["duration"]?.int == -1)
let description = extractDescription(from: content) ?? ""
var chapters = extractChapters(from: content)
if chapters.isEmpty, !description.isEmpty {
chapters = extractChapters(from: description)
}
let length = details["duration"]?.double ?? 0
return Video(
instanceID: account.instanceID,
app: .piped,
instanceURL: account.instance.apiURL,
videoID: extractID(from: content),
title: details["title"]?.string ?? "",
author: author,
length: length,
published: published ?? "",
views: details["views"]?.int ?? 0,
description: description,
channel: Channel(app: .piped, id: channelId, name: author, thumbnailURL: authorThumbnailURL, subscriptionsCount: subscriptionsCount),
thumbnails: thumbnails,
live: live,
short: details["isShort"]?.bool ?? (length <= Video.shortLength),
publishedAt: publishedAt,
likes: details["likes"]?.int,
dislikes: details["dislikes"]?.int,
streams: extractStreams(from: content),
related: extractRelated(from: content),
chapters: extractChapters(from: content)
)
}
private func extractID(from content: JSON) -> Video.ID {
content.dictionaryValue["url"]?.string?.components(separatedBy: "?v=").last ??
extractThumbnailURL(from: content)?.relativeString.components(separatedBy: "/")[4] ?? ""
}
private func extractThumbnailURL(from content: JSON) -> URL? {
content.dictionaryValue["thumbnail"]?.url ?? content.dictionaryValue["thumbnailUrl"]?.url
}
private func buildThumbnailURL(from content: JSON, quality: Thumbnail.Quality) -> URL? {
guard let thumbnailURL = extractThumbnailURL(from: content) else {
return nil
}
return URL(
string: thumbnailURL
.absoluteString
.replacingOccurrences(of: "hqdefault", with: quality.filename)
.replacingOccurrences(of: "maxresdefault", with: quality.filename)
)
}
private func extractUserPlaylist(from json: JSON) -> Playlist? {
let id = json["id"].string ?? ""
let title = json["name"].string ?? ""
let visibility = Playlist.Visibility.private
return Playlist(id: id, title: title, visibility: visibility)
}
private func extractDescription(from content: JSON) -> String? {
guard let description = content.dictionaryValue["description"]?.string else { return nil }
return replaceHTML(description)
}
private func replaceHTML(_ string: String) -> String {
var string = string.replacingOccurrences(
of: "<br/>|<br />|<br>",
with: "\n",
options: .regularExpression,
range: nil
)
let linkRegex = #"(<a\s+(?:[^>]*?\s+)?href=\"[^"]*\">[^<]*<\/a>)"#
let hrefRegex = #"href=\"([^"]*)\">"#
guard let hrefRegex = try? NSRegularExpression(pattern: hrefRegex) else { return string }
string = string.replacingMatches(regex: linkRegex) { matchingGroup in
let results = hrefRegex.matches(in: matchingGroup, range: NSRange(matchingGroup.startIndex..., in: matchingGroup))
if let result = results.first {
if let swiftRange = Range(result.range(at: 1), in: matchingGroup) {
return String(matchingGroup[swiftRange])
}
}
return matchingGroup
}
string = string
.replacingOccurrences(of: "&amp;", with: "&")
.replacingOccurrences(of: "&nbsp;", with: " ")
.replacingOccurrences(
of: "<[^>]+>",
with: "",
options: .regularExpression,
range: nil
)
return string
}
private func extractVideos(from content: JSON) -> [Video] {
content.arrayValue.compactMap(extractVideo(from:))
}
private func extractStreams(from content: JSON) -> [Stream] {
var streams = [Stream]()
if let hlsURL = content.dictionaryValue["hls"]?.url {
streams.append(Stream(instance: account.instance, hlsURL: hlsURL))
}
let audioStreams = content
.dictionaryValue["audioStreams"]?
.arrayValue
.filter { $0.dictionaryValue["format"]?.string == "M4A" }
.filter { stream in
let type = stream.dictionaryValue["audioTrackType"]?.string
return type == nil || type == "ORIGINAL"
}
.sorted {
$0.dictionaryValue["bitrate"]?.int ?? 0 >
$1.dictionaryValue["bitrate"]?.int ?? 0
} ?? []
guard let audioStream = audioStreams.first else {
return streams
}
let videoStreams = content.dictionaryValue["videoStreams"]?.arrayValue ?? []
for videoStream in videoStreams {
let videoCodec = videoStream.dictionaryValue["codec"]?.string ?? ""
if Self.disallowedVideoCodecs.contains(where: videoCodec.contains) {
continue
}
guard let audioAssetUrl = audioStream.dictionaryValue["url"]?.url,
let videoAssetUrl = videoStream.dictionaryValue["url"]?.url
else {
continue
}
let audioAsset = AVURLAsset(url: audioAssetUrl)
let videoAsset = AVURLAsset(url: videoAssetUrl)
let videoOnly = videoStream.dictionaryValue["videoOnly"]?.bool ?? true
let quality = videoStream.dictionaryValue["quality"]?.string ?? "unknown"
let qualityComponents = quality.components(separatedBy: "p")
let fps = qualityComponents.count > 1 ? Int(qualityComponents[1]) : 30
let resolution = Stream.Resolution.from(resolution: quality, fps: fps)
let videoFormat = videoStream.dictionaryValue["format"]?.string
let bitrate = videoStream.dictionaryValue["bitrate"]?.int
var requestRange: String?
if let initStart = videoStream.dictionaryValue["initStart"]?.int,
let initEnd = videoStream.dictionaryValue["initEnd"]?.int
{
requestRange = "\(initStart)-\(initEnd)"
} else if let indexStart = videoStream.dictionaryValue["indexStart"]?.int,
let indexEnd = videoStream.dictionaryValue["indexEnd"]?.int
{
requestRange = "\(indexStart)-\(indexEnd)"
} else {
requestRange = nil
}
if videoOnly {
streams.append(
Stream(
instance: account.instance,
audioAsset: audioAsset,
videoAsset: videoAsset,
resolution: resolution,
kind: .adaptive,
videoFormat: videoFormat,
bitrate: bitrate,
requestRange: requestRange
)
)
} else {
streams.append(
SingleAssetStream(
instance: account.instance,
avAsset: videoAsset,
resolution: resolution,
kind: .stream
)
)
}
}
return streams
}
private func extractRelated(from content: JSON) -> [Video] {
content
.dictionaryValue["relatedStreams"]?
.arrayValue
.compactMap(extractVideo(from:)) ?? []
}
private func extractComment(from content: JSON) -> Comment? {
let details = content.dictionaryValue
let author = details["author"]?.string ?? ""
let commentorUrl = details["commentorUrl"]?.string
let channelId = commentorUrl?.components(separatedBy: "/")[2] ?? ""
let commentText = extractCommentText(from: details["commentText"]?.stringValue)
let commentId = details["commentId"]?.string ?? UUID().uuidString
// Sanity checks: return nil if required data is missing
if commentText.isEmpty || commentId.isEmpty || author.isEmpty {
return nil
}
return Comment(
id: commentId,
author: author,
authorAvatarURL: details["thumbnail"]?.string ?? "",
time: details["commentedTime"]?.string ?? "",
pinned: details["pinned"]?.bool ?? false,
hearted: details["hearted"]?.bool ?? false,
likeCount: details["likeCount"]?.int ?? 0,
text: commentText,
repliesPage: details["repliesPage"]?.string,
channel: Channel(app: .piped, id: channelId, name: author)
)
}
private func extractCommentText(from string: String?) -> String {
guard let string, !string.isEmpty else { return "" }
return replaceHTML(string)
}
private func extractChapters(from content: JSON) -> [Chapter] {
guard let chapters = content.dictionaryValue["chapters"]?.array else {
return .init()
}
return chapters.compactMap { chapter in
guard let title = chapter["title"].string,
let image = chapter["image"].url,
let start = chapter["start"].double
else {
return nil
}
return Chapter(title: title, image: image, start: start)
}
}
private func contentItemsDictionary(from content: JSON) -> JSON {
if let key = Self.contentItemsKeys.first(where: { content.dictionaryValue.keys.contains($0) }),
let items = content.dictionaryValue[key]
{
return items
}
return .null
}
}