Add podcast namespace guid tag

Sources/FeedKit/FeedNamespace.swift

@@ -57,6 +57,8 @@ enum FeedNamespace: CaseIterable {
   /// Represents the Atom feed namespace, typically used for syndication
   /// in the Atom format.
   case atom
+  /// Represents the podcast namespace. 
+  case podcast
 
   // MARK: Internal
 
@@ -81,6 +83,8 @@ enum FeedNamespace: CaseIterable {
       "xmlns:yt"
     case .atom:
       "xmlns:atom"
+    case .podcast:
+      "xmlns:podcast"
     }
   }
 
@@ -105,6 +109,8 @@ enum FeedNamespace: CaseIterable {
       "http://www.youtube.com/xml/schemas/2015"
     case .atom:
       "http://www.w3.org/2005/Atom"
+    case .podcast:
+      "https://podcastindex.org/namespace/1.0"
     }
   }
 }
@@ -145,6 +151,9 @@ extension FeedNamespace {
 
     case .atom:
       feed.channel?.atom != nil
+
+    case .podcast:
+      feed.channel?.podcast != nil
     }
   }
 

Sources/FeedKit/Feeds/RSS/RSSFeedChannel.swift

@@ -60,7 +60,8 @@ public struct RSSFeedChannel {
     dublinCore: DublinCore? = nil,
     iTunes: ITunes? = nil,
     syndication: Syndication? = nil,
-    atom: Atom? = nil
+    atom: Atom? = nil,
+    podcast: Podcast? = nil
   ) {
     self.title = title
     self.link = link
@@ -86,6 +87,7 @@ public struct RSSFeedChannel {
     self.iTunes = iTunes
     self.syndication = syndication
     self.atom = atom
+    self.podcast = podcast
   }
 
   // MARK: Public
@@ -307,6 +309,10 @@ public struct RSSFeedChannel {
   /// and hub information.
   /// See https://www.w3.org/TR/websub/#discovery
   public var atom: Atom?
+
+  /// A wholistic RSS namespace for podcasting that is meant to synthesize the fragmented world of podcast namespaces.
+  /// See https://github.com/Podcastindex-org/podcast-namespace
+  public var podcast: Podcast?
 }
 
 // MARK: - Sendable
@@ -349,6 +355,7 @@ extension RSSFeedChannel: Codable {
     case iTunes = "itunes"
     case syndication = "sy"
     case atom
+    case podcast
   }
 
   public init(from decoder: any Decoder) throws {
@@ -378,6 +385,7 @@ extension RSSFeedChannel: Codable {
     iTunes = try container.decodeIfPresent(ITunes.self, forKey: CodingKeys.iTunes)
     syndication = try container.decodeIfPresent(Syndication.self, forKey: CodingKeys.syndication)
     atom = try container.decodeIfPresent(Atom.self, forKey: CodingKeys.atom)
+    podcast = try container.decodeIfPresent(Podcast.self, forKey: CodingKeys.podcast)
   }
 
   public func encode(to encoder: any Encoder) throws {
@@ -407,5 +415,6 @@ extension RSSFeedChannel: Codable {
     try container.encodeIfPresent(iTunes, forKey: CodingKeys.iTunes)
     try container.encodeIfPresent(syndication, forKey: CodingKeys.syndication)
     try container.encodeIfPresent(atom, forKey: CodingKeys.atom)
+    try container.encodeIfPresent(podcast, forKey: CodingKeys.podcast)
   }
 }

Sources/FeedKit/Namespaces/Podcast/Podcast.swift

@@ -0,0 +1,58 @@
+import Foundation
+import XMLKit
+
+/// The podcast namespace
+///
+/// See https://github.com/Podcastindex-org/podcast-namespace
+public struct Podcast {
+  // MARK: Lifecycle
+
+  public init(
+    guid: String? = nil
+
+  ) {
+    self.guid = guid
+  }
+
+  // MARK: Public
+  /// This element is used to declare a unique, global identifier for a podcast. 
+  /// See https://github.com/Podcastindex-org/podcast-namespace/blob/main/docs/tags/guid.md
+  public var guid: String?
+}
+
+// MARK: - XMLNamespaceDecodable
+
+extension Podcast: XMLNamespaceCodable {}
+
+// MARK: - Sendable
+
+extension Podcast: Sendable {}
+
+// MARK: - Equatable
+
+extension Podcast: Equatable {}
+
+// MARK: - Hashable
+
+extension Podcast: Hashable {}
+
+// MARK: - Codable
+
+extension Podcast: Codable {
+  private enum CodingKeys: String, CodingKey {
+    case guid = "podcast:guid"
+  }
+
+  public init(from decoder: any Decoder) throws {
+    let container: KeyedDecodingContainer<CodingKeys> = try decoder.container(
+      keyedBy: CodingKeys.self)
+
+    guid = try container.decodeIfPresent(String.self, forKey: CodingKeys.guid)
+  }
+
+  public func encode(to encoder: any Encoder) throws {
+    var container: KeyedEncodingContainer<CodingKeys> = encoder.container(keyedBy: CodingKeys.self)
+
+    try container.encodeIfPresent(guid, forKey: CodingKeys.guid)
+  }
+}