FeedKit

FeedKit is a Swift library for Reading and Generating RSS, RDF, Atom, and JSON feeds.

Features

• Atom
• RSS
• RDF (RSS 1.0 and 0.90)
• JSON
• Namespaces
  • Atom
  • Dublin Core
  • Syndication
  • Content
  • Media RSS
  • Geo RSS
  • GML
  • iTunes
  • YouTube
  • Podcast
  • Feed Paging and Archiving
  • Comment API
  • Podlove Simple Chapters
• Examples
• Documentation
• Unit Tests

Feed Reader

Feed reading can be made with a dedicated type, such as RSSFeed, RDFFeed, AtomFeed and JSONFeed, or a universal type Feed.

Dedicated

When you know the type of feed to be read, use a dedicated type.

try await RSSFeed(urlString: "https://developer.apple.com/news/rss/news.rss")

Universal

When you don't know the type of feed, use the universal Feed enum type.

The Feed enum type handles RSS, RDF, Atom and JSON feeds and will determine the type of feed before reading, parsing and decoding occurs.

// Read any type of feed
let feed = try await Feed(urlString: "https://surprise.example/feed")

// Use a switch to get the resulting feed model
switch feed {
case let .atom(feed): // An AtomFeed instance
case let .rss(feed): // An RSSFeed instance
case let .rdf(feed): // An RDFFeed instance
case let .json(feed): // A JSONFeed instance
}

Manual Feed Type Detection

The universal Feed enum above automatically determines the feed type, so you generally don't need to do it manually. However, using a FeedType enum can be helpful when you want to identify the type of feed without the overhead of parsing and decoding.

let feedType = try FeedType(data: data)

// Detect feed type
switch feedType {
case .rss: // RSS feed detected
case .rdf: // RDF feed detected
case .atom: // Atom feed detected
case .json: // JSON feed detected
}

// Or feed content type
if feedType.isXML {
  // XML feed detected
} else if feedType.isJSON {
  // JSON feed detected
}

Initializers

All feed types conform to FeedInitializable, sharing multiple common initializers. They provide a flexible way to read feeds from the most common sources.

Note: The URL-fetching initializers require URLSession, which Foundation does not provide on WASI. On WASI, use the local fileURL:, string:, and data: initializers.

From a URL String:

init(urlString: String) async throws

From a URL, handling both local file URLs and remote URLs:

init(url: URL) async throws

From a local file URL:

init(fileURL url: URL) throws

From a remote URL:

init(remoteURL url: URL) async throws

From an XML or JSON String:

init(string: String) throws

From raw Data:

init(data: Data) throws

Feed Generator

XML

To generate an XML string for any given XML feed, create an instance of an RSSFeed or AtomFeed and populate it with the necessary data.

let feed = RSSFeed(
  channel: .init(
    title: "Breaking News",
    link: "http://www.breakingnews.example/",
    description: "Get the latest updates as they happen.",
    // ...
    items: [
      .init(
        title: "Breaking News: All Hearts are Joyful",
        link: "http://breakingnews.example/2025/01/09/joyful-hearts",
        description: "A heartwarming story of unity and celebration."
        // ...
      ),
    ]
  )
)

Then call toXMLString(formatted:) to generate the XML string.

try feed.toXMLString(formatted: true)

<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0">
  <channel>
    <title>Breaking News</title>
    <link>http://www.breakingnews.example/</link>
    <description>Get the latest updates as they happen.</description>
    <item>
      <title>Breaking News: All Hearts are Joyful</title>
      <link>http://breakingnews.example/2025/01/09/joyful-hearts</link>
      <description>A heartwarming story of unity and celebration.</description>
    </item>
  </channel>
</rss>

JSON

In the same way, you can create an instance of a JSONFeed, populate it, and then call toJSONString(formatted:) to generate a JSON string.

try feed.toJSONString(formatted: true)

Feed Models

The RSS, RDF, Atom, and JSON feed models are highly comprehensive, especially when combined with all the supported namespaces. Below is a small preview of what’s available.

RSS

channel.title
channel.link
channel.description
channel.language
channel.copyright
channel.managingEditor
channel.webMaster
channel.pubDate
channel.lastBuildDate
channel.categories
channel.generator
channel.docs
channel.cloud
channel.rating
channel.ttl
channel.image
channel.textInput
channel.skipHours
channel.skipDays
// ...
channel.dublinCore
channel.syndication
channel.iTunes
channel.atom
// ...

let item = channel.items?.first

item?.title
item?.link
item?.description
item?.author
item?.categories
item?.comments
item?.enclosure
item?.guid
item?.pubDate
item?.source
//...
item?.dublinCore
item?.content
item?.iTunes
item?.media
// ...

RDF

feed.channel?.title
feed.channel?.link
feed.channel?.description
// ...
feed.channel?.dublinCore
feed.channel?.syndication

// In RSS 1.0 the items are siblings of the channel
let item = feed.items?.first

item?.title
item?.link
item?.description
// ...
item?.dublinCore
item?.content

Atom

feed.title
feed.subtitle
feed.links
feed.updated
feed.authors
feed.contributors
feed.id
feed.generator
feed.icon
feed.logo
feed.rights
// ...

let entry = feed.entries?.first

entry?.title
entry?.summary
entry?.authors
entry?.contributors
entry?.links
entry?.updated
entry?.categories
entry?.id
entry?.content
entry?.published
entry?.source
entry?.rights
// ...
entry?.media
entry?.youTube

JSON

feed.version
feed.title
feed.homePageURL
feed.feedURL
feed.description
feed.userComment
feed.nextURL
feed.icon
feed.favicon
feed.author
feed.expired
feed.hubs
// ...

let item = feed.items?.first

item?.id
item?.url
item?.externalURL
item?.title
item?.contentText
item?.contentHtml
item?.summary
item?.image
item?.bannerImage
item?.datePublished
item?.dateModified
item?.author
item?.url
item?.tags
item?.attachments
// ...

Installation

To add FeedKit to your Xcode project, follow these steps:

• Open your project in Xcode and go to the "File" menu.
• Select "Add Package Dependencies…"
• Enter the "Package URL": https://github.com/nmdias/FeedKit
• Select "Add Package"

Performance

Parsing speed across versions is tracked in PERFORMANCE.md. To measure and add a row:

cd Benchmarks
./bench.sh

License

FeedKit is released under the MIT license. See LICENSE for details.