[Obsolete, but see end of thread] Add Combine support and RxSwift extension

.gitignore

@@ -4,3 +4,4 @@ xcuserdata
 Carthage/
 .build
 Siesta.xcodeproj/xcshareddata/xcbaselines
+.idea/

Cartfile.private

@@ -2,6 +2,7 @@
 
 github "Alamofire/Alamofire"
 # github "ReactiveCocoa/ReactiveCocoa" "master"  # add to Cartfile if/when it has tests
+github "ReactiveX/RxSwift"
 
 # Testing
 

Cartfile.resolved

@@ -1,3 +1,4 @@
 github "Alamofire/Alamofire" "5.0.5"
 github "Quick/Nimble" "v8.0.5"
+github "ReactiveX/RxSwift" "5.1.1"
 github "pcantrell/Quick" "d91676d00600c42f9b55349765b1f1099141bfba"

Examples/GithubBrowser/Podfile

@@ -5,3 +5,20 @@ target 'GithubBrowser' do
 
   pod 'Siesta/UI', path: '../..'
 end
+
+target "GithubBrowserCombine" do
+	use_frameworks!
+	platform :ios, '13.0'
+	pod 'Siesta/UI', path: '../..'
+	pod 'CombineCocoa'
+	pod 'CombineExt'
+	pod 'CombineDataSources'
+end
+
+target "GithubBrowserRx" do
+	use_frameworks!
+	pod 'Siesta/UI', path: '../..'
+	pod 'RxSwift'
+	pod 'RxCocoa'
+	pod 'RxOptional'
+end

Examples/GithubBrowser/Podfile.lock

@@ -1,18 +1,53 @@
 PODS:
+  - CombineCocoa (0.2.0)
+  - CombineDataSources (0.2.5)
+  - CombineExt (1.2.0)
+  - RxCocoa (5.1.1):
+    - RxRelay (~> 5)
+    - RxSwift (~> 5)
+  - RxOptional (4.1.0):
+    - RxCocoa (~> 5)
+    - RxSwift (~> 5)
+  - RxRelay (5.1.1):
+    - RxSwift (~> 5)
+  - RxSwift (5.1.1)
   - Siesta/Core (1.5.2)
   - Siesta/UI (1.5.2):
     - Siesta/Core
 
 DEPENDENCIES:
+  - CombineCocoa
+  - CombineDataSources
+  - CombineExt
+  - RxCocoa
+  - RxOptional
+  - RxSwift
   - Siesta/UI (from `../..`)
 
+SPEC REPOS:
+  trunk:
+    - CombineCocoa
+    - CombineDataSources
+    - CombineExt
+    - RxCocoa
+    - RxOptional
+    - RxRelay
+    - RxSwift
+
 EXTERNAL SOURCES:
   Siesta:
     :path: "../.."
 
 SPEC CHECKSUMS:
+  CombineCocoa: 92b2579a9e4a364f8ba94be7fc68335bd3d73d92
+  CombineDataSources: dcbc3b06a038ffdf620b3b4533d3ecaf76ca6a2e
+  CombineExt: f6ad3c8e9a0c85f06e5c66ddd85eb32875d906d2
+  RxCocoa: 32065309a38d29b5b0db858819b5bf9ef038b601
+  RxOptional: b1fcd60856807a564c0215c2184b8d33e7826dc2
+  RxRelay: d77f7d771495f43c556cbc43eebd1bb54d01e8e9
+  RxSwift: 81470a2074fa8780320ea5fe4102807cb7118178
   Siesta: d1e1966af43ffca170f658ad6d987228a5b40873
 
-PODFILE CHECKSUM: 974001388daa9ecbfa915ea0bc4093a33242099c
+PODFILE CHECKSUM: 71f3353904f6db031a60fe5063ce84284832882f
 
 COCOAPODS: 1.10.0

Examples/GithubBrowser/README.md

@@ -51,3 +51,9 @@ Siesta solves all these problems transparently, with minimal code.
 If you hit the GitHub API’s rate limit while running the demo, press the “Log In” button. If you’re experimenting with the demo a lot, you can set `GITHUB_USER` and `GITHUB_PASS` environment variables in the “Run” build scheme to make the app automatically log you in on launch.
 
 You can use a [personal access token](https://github.com/settings/tokens) in place of your password. You don’t need to grant any permissions to your token for this app; just the public access will do.
+
+## Combine and RxSwift
+
+The main view controllers have *Combine and *Rx variants to demonstrate the use of Siesta's reactive extensions, and the project has accompanying Combine and Rx targets.
+
+You might find it instructive to compare the reactive controllers with their non-reactive versions, particularly if you're an existing Siesta user thinking of adopting the reactive extensions.

Examples/GithubBrowser/Source/API/GitHubAPI+Combine.swift

@@ -0,0 +1,15 @@
+import Combine
+
+extension _GitHubAPI {
+
+    /*
+    An unintrusive way to publish isAuthenticated - _GitHubAPI is shared with the other non-Combine examples.
+    In reality if we were using a stored property we'd annotate with @Published.
+    */
+    var isAuthenticatedPublisher: AnyPublisher<Bool, Never> {
+        publisher(for: \.basicAuthHeader)
+                .map { $0 != nil }
+                .eraseToAnyPublisher()
+    }
+
+}

Examples/GithubBrowser/Source/API/GitHubAPI+Rx.swift

@@ -0,0 +1,14 @@
+import RxSwift
+import RxCocoa
+
+extension _GitHubAPI {
+
+    /*
+    An unintrusive way to publish isAuthenticated - _GitHubAPI is shared with the other non-rx examples.
+    In reality we'd do this differently.
+    */
+    var isAuthenticatedObservable: Observable<Bool> {
+        rx.observe(String?.self, "basicAuthHeader").map { $0.map { $0 != nil} ?? false }.distinctUntilChanged()
+    }
+
+}

Examples/GithubBrowser/Source/API/GithubAPI.swift

@@ -5,15 +5,17 @@ import Siesta
 
 let GitHubAPI = _GitHubAPI()
 
-class _GitHubAPI {
+class _GitHubAPI: NSObject { /* NSObject just for reactive extensions */
 
     // MARK: - Configuration
 
     private let service = Service(
         baseURL: "https://api.github.com",
         standardTransformers: [.text, .image])  // No .json because we use Swift 4 JSONDecoder instead of older JSONSerialization
 
-    fileprivate init() {
+    fileprivate override init() {
+        super.init()
+
         #if DEBUG
             // Bare-bones logging of which network calls Siesta makes:
             SiestaLog.Category.enabled = [.network]
@@ -128,7 +130,8 @@ class _GitHubAPI {
         return basicAuthHeader != nil
     }
 
-    private var basicAuthHeader: String? {
+    /* "@objc dynamic" just for reactive extensions */
+    @objc dynamic var basicAuthHeader: String? {
         didSet {
             // These two calls are almost always necessary when you have changing auth for your API:
 
@@ -181,6 +184,16 @@ class _GitHubAPI {
             named: repositoryModel.name)
     }
 
+    func contributors(_ repositoryModel: Repository) -> Resource? {
+        return repository(repositoryModel)
+                .optionalRelative(repositoryModel.contributorsURL)
+    }
+
+    func languages(_ repositoryModel: Repository) -> Resource? {
+        return repository(repositoryModel)
+                .optionalRelative(repositoryModel.languagesURL)
+    }
+
     func currentUserStarred(_ repositoryModel: Repository) -> Resource {
         return service
             .resource("/user/starred")

Examples/GithubBrowser/Source/Info-Combine.plist

@@ -0,0 +1,40 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>en</string>
+	<key>CFBundleExecutable</key>
+	<string>$(EXECUTABLE_NAME)</string>
+	<key>CFBundleIdentifier</key>
+	<string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>$(PRODUCT_NAME)</string>
+	<key>CFBundlePackageType</key>
+	<string>APPL</string>
+	<key>CFBundleShortVersionString</key>
+	<string>1.0</string>
+	<key>CFBundleSignature</key>
+	<string>????</string>
+	<key>CFBundleVersion</key>
+	<string>1</string>
+	<key>LSRequiresIPhoneOS</key>
+	<true/>
+	<key>UILaunchStoryboardName</key>
+	<string>LaunchScreen</string>
+	<key>UIMainStoryboardFile</key>
+	<string>Main</string>
+	<key>UIRequiredDeviceCapabilities</key>
+	<array>
+		<string>armv7</string>
+	</array>
+	<key>UISupportedInterfaceOrientations</key>
+	<array>
+		<string>UIInterfaceOrientationPortrait</string>
+		<string>UIInterfaceOrientationLandscapeLeft</string>
+		<string>UIInterfaceOrientationLandscapeRight</string>
+	</array>
+</dict>
+</plist>

Examples/GithubBrowser/Source/Info-Rx.plist

@@ -0,0 +1,40 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>en</string>
+	<key>CFBundleExecutable</key>
+	<string>$(EXECUTABLE_NAME)</string>
+	<key>CFBundleIdentifier</key>
+	<string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>$(PRODUCT_NAME)</string>
+	<key>CFBundlePackageType</key>
+	<string>APPL</string>
+	<key>CFBundleShortVersionString</key>
+	<string>1.0</string>
+	<key>CFBundleSignature</key>
+	<string>????</string>
+	<key>CFBundleVersion</key>
+	<string>1</string>
+	<key>LSRequiresIPhoneOS</key>
+	<true/>
+	<key>UILaunchStoryboardName</key>
+	<string>LaunchScreen</string>
+	<key>UIMainStoryboardFile</key>
+	<string>Main</string>
+	<key>UIRequiredDeviceCapabilities</key>
+	<array>
+		<string>armv7</string>
+	</array>
+	<key>UISupportedInterfaceOrientations</key>
+	<array>
+		<string>UIInterfaceOrientationPortrait</string>
+		<string>UIInterfaceOrientationLandscapeLeft</string>
+		<string>UIInterfaceOrientationLandscapeRight</string>
+	</array>
+</dict>
+</plist>

Examples/GithubBrowser/Source/UI/RepositoryListViewControllerCombine.swift

@@ -0,0 +1,114 @@
+import UIKit
+import Siesta
+import Combine
+import CombineExt
+import CombineDataSources
+
+class RepositoryListViewController: UITableViewController {
+
+    private var statusOverlay = ResourceStatusOverlay()
+    private var subs = [AnyCancellable]()
+
+    override func viewDidLoad() {
+        super.viewDidLoad()
+
+        view.backgroundColor = SiestaTheme.darkColor
+        statusOverlay.embed(in: self)
+
+        // Standard table view stuff we don't want here (we're sharing the storyboard with the other examples)
+        tableView.dataSource = nil
+        tableView.delegate = nil
+    }
+
+    override func viewDidLayoutSubviews() {
+        statusOverlay.positionToCoverParent()
+    }
+
+    /**
+    The input to this class - the repositories to display.
+
+    Whether it's better to pass in a resource or a publisher here is much the same argument as whether to define
+    APIs in terms of resources or publishers. See UserViewController for a discussion about that.
+    */
+    func configure(repositories: AnyPublisher<Resource? /* [Repository] */, Never>) {
+        /*
+        Oh hey, in the next small handful of lines, let's:
+        - make an api call if necessary to fetch the latest repo list we're to show
+        - display progress and errors while doing that, and
+        - populate the table.
+        */
+        repositories
+                // In this project we have an extension to tell Siesta's status overlay to be
+                // interested in the latest Resource output by a Resource publisher. The following
+                // line gives us a progress spinner, error display and retry functionality.
+                .watchedBy(statusOverlay: statusOverlay)
+
+                // Transform the sequence of Resources into a sequence of their content: [Repository].
+                .flatMapLatest { resource -> AnyPublisher<[Repository], Never> in
+                    resource?.contentPublisher() ?? Just([]).eraseToAnyPublisher()
+                }
+
+                // This is everything we need to populate the table with the list of repos,
+                // courtesy of CombineDataSources.
+                .bind(subscriber: tableView.rowsSubscriber(cellIdentifier: "repo", cellType: RepositoryTableViewCell.self, cellConfig: { cell, indexPath, repo in
+                    cell.repository = repo
+                }))
+                .store(in: &subs)
+    }
+
+    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
+        if segue.identifier == "repoDetail" {
+            if let repositoryVC = segue.destination as? RepositoryViewController,
+               let cell = sender as? RepositoryTableViewCell {
+
+                if let repo = cell.repository {
+                    repositoryVC.repositoryResource = Just(GitHubAPI.repository(repo)).eraseToAnyPublisher()
+                }
+            }
+        }
+    }
+}
+
+class RepositoryTableViewCell: UITableViewCell {
+    @IBOutlet weak var icon: RemoteImageView!
+    @IBOutlet weak var userLabel: UILabel!
+    @IBOutlet weak var repoLabel: UILabel!
+    @IBOutlet weak var starCountLabel: UILabel!
+
+    var repository: Repository? {
+        didSet {
+            userLabel.text = repository?.owner.login
+            repoLabel.text = repository?.name
+            starCountLabel.text = repository?.starCount?.description
+
+            // Note how powerful this next line is:
+            //
+            // • RemoteImageView calls loadIfNeeded() when we set imageURL, so this automatically triggers a network
+            //   request for the image. However...
+            //
+            // • loadIfNeeded() won’t make redundant requests, so no need to worry about whether this avatar is used in
+            //   other table cells, or whether we’ve already requested it! Many cells sharing one image spawn one
+            //   request. One response updates _all_ the cells that image.
+            //
+            // • If imageURL was already set, RemoteImageView calls cancelLoadIfUnobserved() on the old image resource.
+            //   This means that if the user is scrolling fast and table cells are being reused:
+            //
+            //   - a request in progress gets cancelled
+            //   - unless other cells are also waiting on the same image, in which case the request continues, and
+            //   - an image that we’ve already fetch stay available in memory, fully parsed & ready for instant resuse.
+            //
+            // Finally, note that all of this nice behavior is not special magic that’s specific to images. These are
+            // basic Siesta behaviors you can use for resources of any kind. Look at the RemoteImageView source code
+            // and study how it uses the core Siesta API.
+
+            icon.imageURL = repository?.owner.avatarURL
+        }
+    }
+}
+
+// Required by CombineDataSources for binding the repositories to the table
+extension Repository: Hashable {
+    public func hash(into hasher: inout Hasher) { url.hash(into: &hasher) }
+
+    public static func ==(lhs: Repository, rhs: Repository) -> Bool { lhs.url == rhs.url }
+}