Render a JSON feed

SiteGenerator/Sources/SiteGenerator/Feeds/JSONFeedPlugin.swift

@@ -0,0 +1,39 @@
+//
+//  JSONFeedPlugin.swift
+//  SiteGenerator
+//
+//  Created by Sami Samhuri on 2019-12-10.
+//
+
+import Foundation
+
+final class JSONFeedPlugin: Plugin {
+    let postRepo: PostRepo
+    let jsonFeedWriter: JSONFeedWriter
+
+    init(
+        postRepo: PostRepo = PostRepo(),
+        jsonFeedWriter: JSONFeedWriter = JSONFeedWriter()
+    ) {
+        self.postRepo = postRepo
+        self.jsonFeedWriter = jsonFeedWriter
+    }
+
+    // MARK: - Plugin methods
+
+    func setUp(site: Site, sourceURL: URL) throws {
+        guard postRepo.postDataExists(at: sourceURL) else {
+            return
+        }
+
+        try postRepo.readPosts(sourceURL: sourceURL, makePath: jsonFeedWriter.urlPathForPost)
+    }
+
+    func render(site: Site, targetURL: URL, templateRenderer: TemplateRenderer) throws {
+        guard !postRepo.isEmpty else {
+            return
+        }
+
+        try jsonFeedWriter.writeFeed(postRepo.postsForFeed, site: site, to: targetURL, with: templateRenderer)
+    }
+}

SiteGenerator/Sources/SiteGenerator/Feeds/JSONFeedWriter.swift

@@ -0,0 +1,98 @@
+//
+//  JSONFeedWriter.swift
+//  SiteGenerator
+//
+//  Created by Sami Samhuri on 2019-12-10.
+//
+
+import Foundation
+
+private struct Feed: Codable {
+    let version = "https://jsonfeed.org/version/1"
+    let title: String
+    let home_page_url: String
+    let feed_url: String
+    let author: FeedAuthor
+    let icon: String?
+    let favicon: String?
+    let items: [FeedItem]
+}
+
+private struct FeedAuthor: Codable {
+    let name: String
+    let avatar: String?
+    let url: String?
+}
+
+private struct FeedItem: Codable {
+    let title: String
+    let date_published: Date
+    let id: String
+    let url: String
+    let external_url: String?
+    let author: FeedAuthor
+    let content_html: String
+    let tags: [String]
+}
+
+final class JSONFeedWriter {
+    let fileManager: FileManager
+    let feedPath: String
+    let postsPath: String
+
+    var baseURL: URL!
+
+    init(fileManager: FileManager = .default, feedPath: String = "feed.json", postsPath: String = "posts") {
+        self.fileManager = fileManager
+        self.feedPath = feedPath
+        self.postsPath = postsPath
+    }
+
+    #warning("These urlPath methods were copied from PostsPlugin and should possibly be moved somewhere else")
+
+    func urlPath(year: Int) -> String {
+        "/\(postsPath)/\(year)"
+    }
+
+    func urlPath(year: Int, month: Month) -> String {
+        urlPath(year: year).appending("/\(month.padded)")
+    }
+
+    func urlPathForPost(date: Date, slug: String) -> String {
+        urlPath(year: date.year, month: Month(date.month)).appending("/\(slug)")
+    }
+
+    func writeFeed(_ posts: [Post], site: Site, to targetURL: URL, with templateRenderer: TemplateRenderer) throws {
+        let items: [FeedItem] = try posts.map { post in
+            let url = site.url.appendingPathComponent(post.path)
+            return FeedItem(
+                title: post.isLink ? "→ \(post.title)" : post.title,
+                date_published: post.date,
+                id: url.absoluteString,
+                url: url.absoluteString,
+                external_url: post.link?.absoluteString,
+                author: FeedAuthor(name: post.author, avatar: nil, url: nil),
+                content_html: try templateRenderer.renderTemplate(name: "feed-post.html", context: [
+                    "post": post,
+                ]),
+                tags: post.tags
+            )
+        }
+        let avatar = site.avatarPath.map(site.url.appendingPathComponent)
+        let feed: Feed = Feed(
+            title: site.title,
+            home_page_url: site.url.absoluteString,
+            feed_url: site.url.appendingPathComponent(feedPath).absoluteString,
+            author: FeedAuthor(name: site.author, avatar: avatar?.absoluteString, url: site.url.absoluteString),
+            icon: site.iconPath.map(site.url.appendingPathComponent)?.absoluteString,
+            favicon: site.faviconPath.map(site.url.appendingPathComponent)?.absoluteString,
+            items: items
+        )
+        let encoder = JSONEncoder()
+        encoder.dateEncodingStrategy = .iso8601
+        encoder.outputFormatting = [.prettyPrinted, .withoutEscapingSlashes]
+        let feedJSON = try encoder.encode(feed)
+        let feedURL = targetURL.appendingPathComponent(feedPath)
+        try feedJSON.write(to: feedURL, options: [.atomic])
+    }
+}

SiteGenerator/Sources/SiteGenerator/Generator/HumanSite.swift

@@ -17,6 +17,9 @@ struct HumanSite: Codable {
     let template: String?
     let styles: [String]?
     let scripts: [String]?
+    let avatar: String?
+    let icon: String?
+    let favicon: String?
 }
 
 extension Site {
@@ -29,7 +32,10 @@ extension Site {
             url: humanSite.url,
             template: humanSite.template ?? "page",
             styles: humanSite.styles ?? [],
-            scripts: humanSite.scripts ?? []
+            scripts: humanSite.scripts ?? [],
+            avatarPath: humanSite.avatar,
+            iconPath: humanSite.icon,
+            faviconPath: humanSite.favicon
         )
     }
 }

SiteGenerator/Sources/SiteGenerator/Generator/Site.swift

@@ -16,6 +16,11 @@ public struct Site {
     public let template: String
     public let styles: [String]
     public let scripts: [String]
+
+    // Used for JSON feed
+    public let avatarPath: String?
+    public let iconPath: String?
+    public let faviconPath: String?
 }
 
 extension Site {

SiteGenerator/Sources/SiteGenerator/main.swift

@@ -13,7 +13,7 @@ func main(sourcePath: String, targetPath: String) throws {
     let targetURL = URL(fileURLWithPath: targetPath)
     let generator = try Generator(
         sourceURL: sourceURL,
-        plugins: [ProjectsPlugin(), PostsPlugin(), RSSFeedPlugin()],
+        plugins: [ProjectsPlugin(), PostsPlugin(), RSSFeedPlugin(), JSONFeedPlugin()],
         renderers: [LessRenderer(), MarkdownRenderer()]
     )
     try generator.generate(targetURL: targetURL)

site.json

@@ -8,5 +8,8 @@
     "/css/normalize.css",
     "/css/style.css"
   ],
-  "scripts": []
+  "scripts": [],
+  "icon": "images/apple-touch-icon-300.png",
+  "favicon": "images/apple-touch-icon-80.png",
+  "avatar": "images/me.jpg",
 }