Cleaned the PostList API a bit with a list of posts and a selected post id init parameters;

Using a computed property for the list and navigation link selections;
Listing now has a computed property to return an array of Posts.

Author: Fábio Oliveira

Reddit-macOS/ContentView.swift

@@ -15,7 +15,7 @@ struct ContentView : View {
     @State private var showSortSheet: Bool = false
     @State private var showSubredditSheet: Bool = false
 
-    @State private var selectedPost: String? = nil
+    @State private var selectedPostId: String? = nil
 
     @EnvironmentObject private var state: ContentViewState
 
@@ -26,8 +26,13 @@ struct ContentView : View {
                 Url(API.subredditURL(state.subreddit, sortBy))
                 Query(["raw_json":"1"])
             }) { listing in
-                PostList(listing: listing, subreddit: self.state.subreddit, sortBy: self.state.sortBy)
+                if listing != nil {
+                    PostList(posts: listing!.posts, subreddit: self.state.subreddit, sortBy: self.state.sortBy, selectedPostId: self.$selectedPostId)
                     .frame(minWidth: 300)
+                }
+                else {
+                    Text("Error while loading posts").frame(minWidth: 300, minHeight: 300)
+                }
                 /// Spinner when loading
                 SpinnerView()
                     .frame(minWidth: 300, minHeight: 300)

Reddit-macOS/Views/PostList.swift

@@ -10,39 +10,64 @@ import SwiftUI
 import Request
 
 struct PostList: View {
-    let listing: Listing?
+    let posts: [Post]
     let subreddit: String
     let sortBy: SortBy
-    
-    @State private var selection: String? = nil
-    @State private var selectedPostIds: Set<String> = Set()
+
+    @Binding var selectedPostId: String?
+
+    private var selectedPostIds: Binding<Set<String>> {
+        Binding(
+            get: {
+                if let selectedPostId = self.selectedPostId {
+                    return Set(arrayLiteral: selectedPostId)
+                }
+                else {
+                    return Set()
+                }
+        },
+            set: {
+                self.selectedPostId = $0.first
+        }
+        )
+    }
+
+    private var selectedNavigationLink: Binding<String?> {
+        Binding<String?>(
+            get: {
+                return self.selectedPostId
+        },
+            set: { selectedPostId in
+                // Absorbing any change that NavigationLink does to its selection property
+        }
+        )
+    }
 
     var body: some View {
-        List(selection: $selectedPostIds) {
+        List(selection: selectedPostIds) {
             Section(header: Text("\(subreddit) | \(sortBy.rawValue)")) {
                 /// List of `PostView`s when loaded
-                ForEach(listing != nil ? listing!.data.children.map { $0.data } : []) { post in
+                ForEach(posts) { post in
                     VStack {
-                        NavigationLink(destination: PostDetailView(post: post), tag: post.id, selection: self.$selection) { EmptyView() }
+                        NavigationLink(destination: PostDetailView(post: post), tag: post.id, selection: self.selectedNavigationLink) { EmptyView() }
                         PostView(post: post)
-                            .tag(post.id)
-                            .padding(EdgeInsets(top: 5, leading: 0, bottom: 5, trailing: 0))
-                            .contentShape(Rectangle())
-                            /// Double-click to open a new window for the `PostDetailView`
-                            .onTapGesture(count: 2) {
-                                let detailView = PostDetailView(post: post)
-                                
-                                let controller = DetailWindowController(rootView: detailView)
-                                controller.window?.title = post.title
-                                controller.showWindow(nil)
-                        }
-                            /// Adding after the double tap so that double tap takes precedence
-                        .onTapGesture(count: 1) {
-                            self.selection = post.id
-                            self.selectedPostIds = Set(arrayLiteral: post.id)
-                        }
                     }
                     .tag(post.id)
+                    .padding(EdgeInsets(top: 5, leading: 0, bottom: 5, trailing: 0))
+                    .contentShape(Rectangle())
+
+                        /// Double-click to open a new window for the `PostDetailView`
+                        .onTapGesture(count: 2) {
+                            let detailView = PostDetailView(post: post)
+
+                            let controller = DetailWindowController(rootView: detailView)
+                            controller.window?.title = post.title
+                            controller.showWindow(nil)
+                    }
+                        /// Adding after the double tap so that double tap takes precedence
+                        .onTapGesture(count: 1) {
+                            self.selectedPostId = post.id
+                    }
                 }
             }
         }

Shared/Models/Listing.swift

@@ -11,6 +11,11 @@ import Foundation
 /// Root of Reddit API response
 struct Listing: Decodable {
     let data: ListingData
+    var posts: [Post] {
+        return data.children.map { (postData) -> Post in
+            postData.data
+        }
+    }
 
     struct ListingData: Decodable {
         let children: [PostData]