Refactor My Profile to use RxSwift

Podfile

@@ -39,6 +39,8 @@ target 'WordPress', :exclusive => true do
   pod 'WPMediaPicker', '~> 0.7.3'
   pod 'ReactiveCocoa', '~> 2.4.7'
   pod 'FormatterKit', '~> 1.8.0'
+  pod 'RxSwift', '~> 2.1.0'
+  pod 'RxCocoa', '~> 2.1.0'
 end
 
 target 'WordPressTodayWidget', :exclusive => true do
@@ -53,6 +55,7 @@ target :WordPressTest, :exclusive => true do
   pod 'Specta', '1.0.5'
   pod 'Expecta', '0.3.2'
   pod 'Nimble', '~> 3.0.0'
+  pod 'RxSwift', '~> 2.1.0'
 end
 
 target 'UITests', :exclusive => true do

Podfile.lock

@@ -135,6 +135,9 @@ PODS:
   - ReactiveCocoa/no-arc (2.4.7)
   - ReactiveCocoa/UI (2.4.7):
     - ReactiveCocoa/Core
+  - RxCocoa (2.1.0):
+    - RxSwift (~> 2.0)
+  - RxSwift (2.1.0)
   - Simperium (0.8.10):
     - Simperium/DiffMatchPach (= 0.8.10)
     - Simperium/JRSwizzle (= 0.8.10)
@@ -205,6 +208,8 @@ DEPENDENCIES:
   - OHHTTPStubs/Swift (~> 4.6.0)
   - Reachability (= 3.2)
   - ReactiveCocoa (~> 2.4.7)
+  - RxCocoa (~> 2.1.0)
+  - RxSwift (~> 2.1.0)
   - Simperium (= 0.8.10)
   - Specta (= 1.0.5)
   - SVProgressHUD (~> 1.1.3)
@@ -275,6 +280,8 @@ SPEC CHECKSUMS:
   PDKTZipArchive: 81c4824eb5587131e422fc58b92c043c4aa96466
   Reachability: 33e18b67625424e47b6cde6d202dce689ad7af96
   ReactiveCocoa: eb38dee0a0e698f73a9b25e5c1faea2bb4c79240
+  RxCocoa: 79b5feb8378545336e756a0a33fcf5e95050b71c
+  RxSwift: 110fb07f81c17c2c3b3254d168363057b1880d18
   Simperium: f507d9b400c499048a98fe728a0b2b9956fd14c1
   Specta: ac94d110b865115fe60ff2c6d7281053c6f8e8a2
   SVProgressHUD: 748080e4f36e603f6c02aec292664239df5279c1

WordPress/Classes/Models/ManagedAccountSettings.swift

@@ -103,3 +103,6 @@ enum AccountSettingsChange {
         }
     }
 }
+
+typealias AccountSettingsChangeWithString = String -> AccountSettingsChange
+typealias AccountSettingsChangeWithInt = Int -> AccountSettingsChange

WordPress/Classes/Services/AccountService+Rx.swift

@@ -0,0 +1,51 @@
+import Foundation
+import RxSwift
+import RxCocoa
+
+extension AccountService {
+    /// Observable that emits new values when the default account is set
+    ///
+    /// - warning: This should only be observed from the main thread, otherwise behavior is undefined
+    var defaultAccountObjectID: Observable<NSManagedObjectID?> {
+        return NSNotificationCenter.defaultCenter()
+            .rx_notification(WPAccountDefaultWordPressComAccountChangedNotification)
+            .map({ ($0.object as! WPAccount?)?.objectID })
+            .startWith(defaultWordPressComAccount()?.objectID)
+    }
+
+    /// Observable that emits values when there is a change in the default account.
+    /// This can be that the default account is set or removed, or one of its properties changes.
+    ///
+    /// - warning: This should only be observed from the main thread, otherwise behavior is undefined
+    var defaultAccountChanged: Observable<WPAccount?> {
+        // Keep a reference to the context to avoid having to reference self
+        // within the closure
+        let context = managedObjectContext
+
+        return defaultAccountObjectID
+            // When the default account is set return the values of this new signal
+            .flatMapLatest({ (objectID) -> Observable<WPAccount?> in
+                if let objectID = objectID,
+                    let account = try? context.existingObjectWithID(objectID) as? WPAccount {
+
+                    return NSNotificationCenter.defaultCenter()
+                        .rx_notification(NSManagedObjectContextObjectsDidChangeNotification, object: context)
+                        // Transform the notifications into the changed account if it changed
+                        .map({ (note) -> WPAccount? in
+                            guard let updatedObjects = note.userInfo?[NSUpdatedObjectsKey] as? Set<NSManagedObject> else {
+                                return nil
+                            }
+
+                            let matchingObject = updatedObjects.filter({ $0.objectID == objectID }).first
+                            return matchingObject as? WPAccount
+                        })
+                        // A nil value here means the change didn't affect the current account
+                        .filter({ $0 != nil })
+                        .startWith(account)
+                } else {
+                    // If the default account was removed, just send a nil value
+                    return Observable.just(nil)
+                }
+            })
+    }
+}

WordPress/Classes/Services/AccountService.m

@@ -74,14 +74,22 @@ - (void)setDefaultWordPressComAccount:(WPAccount *)account
     [[NSUserDefaults standardUserDefaults] synchronize];
 
     NSManagedObjectID *accountID = account.objectID;
-    dispatch_async(dispatch_get_main_queue(), ^{
+    void (^notifyAccountChange)() = ^{
         NSManagedObjectContext *mainContext = [[ContextManager sharedInstance] mainContext];
         NSManagedObject *accountInContext = [mainContext existingObjectWithID:accountID error:nil];
         [[NSNotificationCenter defaultCenter] postNotificationName:WPAccountDefaultWordPressComAccountChangedNotification object:accountInContext];
 
         [[PushNotificationsManager sharedInstance] registerForRemoteNotifications];
         [[InteractiveNotificationsHandler sharedInstance] registerForUserNotifications];
-    });
+    };
+    if ([NSThread isMainThread]) {
+        // This is meant to help with testing account observers.
+        // Short version: dispatch_async and XCTest asynchronous helpers don't play nice with each other
+        // Long version: see the comment in https://github.com/wordpress-mobile/WordPress-iOS/blob/2f9a2100ca69d8f455acec47a1bbd6cbc5084546/WordPress/WordPressTest/AccountServiceRxTests.swift#L7
+        notifyAccountChange();
+    } else {
+        dispatch_async(dispatch_get_main_queue(), notifyAccountChange);
+    }
 }
 
 /**

WordPress/Classes/Services/AccountSettingsService.swift

@@ -1,4 +1,6 @@
 import Foundation
+import RxCocoa
+import RxSwift
 
 let AccountSettingsServiceChangeSaveFailedNotification = "AccountSettingsServiceChangeSaveFailed"
 
@@ -28,13 +30,6 @@ struct AccountSettingsService {
         })
     }
 
-    func subscribeSettings(next: AccountSettings? -> Void) -> AccountSettingsSubscription {
-        return AccountSettingsSubscription(userID: userID, context: context, changed: { (managedSettings) -> Void in
-            let settings = managedSettings.map({ AccountSettings(managed: $0) })
-            next(settings)
-        })
-    }
-
     func saveChange(change: AccountSettingsChange) {
         guard let reverse = try? applyChange(change) else {
             return
@@ -53,8 +48,18 @@ struct AccountSettingsService {
         }
     }
 
+    var settingsObserver: Observable<AccountSettings?> {
+        let notificationCenter = NSNotificationCenter.defaultCenter()
+        let notificationObserver = notificationCenter.rx_notification(NSManagedObjectContextDidSaveNotification, object: context)
+        return notificationObserver.map(getSettings).startWith(getSettings())
+    }
+
+    private func getSettings(_: Any? = nil) -> AccountSettings? {
+        return accountSettingsWithID(self.userID)
+    }
+
     private func applyChange(change: AccountSettingsChange) throws -> AccountSettingsChange {
-        guard let settings = accountSettingsWithID(userID) else {
+        guard let settings = managedAccountSettingsWithID(userID) else {
             DDLogSwift.logError("Tried to apply a change to nonexistent settings (ID: \(userID)")
             throw Errors.NotFound
         }
@@ -67,7 +72,7 @@ struct AccountSettingsService {
     }
 
     private func updateSettings(settings: AccountSettings) {
-        if let managedSettings = accountSettingsWithID(userID) {
+        if let managedSettings = managedAccountSettingsWithID(userID) {
             managedSettings.updateWith(settings)
         } else {
             createAccountSettings(userID, settings: settings)
@@ -76,7 +81,11 @@ struct AccountSettingsService {
         ContextManager.sharedInstance().saveContext(context)
     }
 
-    private func accountSettingsWithID(userID: Int) -> ManagedAccountSettings? {
+    private func accountSettingsWithID(userID: Int) -> AccountSettings? {
+        return managedAccountSettingsWithID(userID).map(AccountSettings.init)
+    }
+
+    private func managedAccountSettingsWithID(userID: Int) -> ManagedAccountSettings? {
         let request = NSFetchRequest(entityName: ManagedAccountSettings.entityName)
         request.predicate = NSPredicate(format: "account.userID = %d", userID)
         request.fetchLimit = 1
@@ -100,37 +109,3 @@ struct AccountSettingsService {
         case NotFound
     }
 }
-
-class AccountSettingsSubscription {
-    private var subscription: NSObjectProtocol? = nil
-
-    init(userID: Int, context: NSManagedObjectContext, changed: ManagedAccountSettings? -> Void) {
-        subscription = NSNotificationCenter.defaultCenter().addObserverForName(NSManagedObjectContextDidSaveNotification, object: context, queue: NSOperationQueue.mainQueue()) {
-            [unowned self]
-            notification in
-            // FIXME: Inspect changed objects in notification instead of fetching for performance (@koke 2015-11-23)
-            let account = self.fetchAccount(userID, context: context)
-            changed(account)
-        }
-
-        let initial = fetchAccount(userID, context: context)
-        dispatch_async(dispatch_get_main_queue()) {
-            changed(initial)
-        }
-    }
-
-    private func fetchAccount(userID: Int, context: NSManagedObjectContext) -> ManagedAccountSettings? {
-        let request = NSFetchRequest(entityName: ManagedAccountSettings.entityName)
-        request.predicate = NSPredicate(format: "account.userID = %d", userID)
-        request.fetchLimit = 1
-        let results = (try? context.executeFetchRequest(request) as! [ManagedAccountSettings]) ?? []
-        return results.first
-    }
-
-    deinit {
-        if let subscription = subscription {
-            NSNotificationCenter.defaultCenter().removeObserver(subscription)
-        }
-    }
-}
-

WordPress/Classes/Utility/ImmuTable.swift

@@ -12,7 +12,7 @@
      struct DestructiveButtonRow: ImmuTableRow {
          static let cell = ImmuTableCell.Class(UITableViewCell.self)
          let title: String
-         let action: ImmuTableActionType?
+         let action: ImmuTableAction?
 
          func configureCell(cell: UITableViewCell) {
              cell.textLabel?.text = title
@@ -137,7 +137,7 @@ public protocol ImmuTableRow {
          }
 
      */
-    var action: ImmuTableActionType? { get }
+    var action: ImmuTableAction? { get }
 
     /// This method is called when an associated cell needs to be configured.
     /// - precondition: You can assume that the passed cell is of the type defined
@@ -297,7 +297,7 @@ public class ImmuTableViewHandler: NSObject, UITableViewDataSource, UITableViewD
 // MARK: - Type aliases
 
 
-public typealias ImmuTableActionType = (ImmuTableRow) -> Void
+public typealias ImmuTableAction = (ImmuTableRow) -> Void
 
 
 // MARK: - Internal testing helpers

WordPress/Classes/Utility/ImmuTableViewController.swift

@@ -0,0 +1,74 @@
+import UIKit
+import RxSwift
+import WordPressShared
+
+typealias ImmuTableRowControllerGenerator = ImmuTableRow -> UIViewController
+
+protocol ImmuTablePresenter: AnyObject {
+    func push(controllerGenerator: ImmuTableRowControllerGenerator) -> ImmuTableAction
+}
+
+extension ImmuTablePresenter where Self: UIViewController {
+    func push(controllerGenerator: ImmuTableRowControllerGenerator) -> ImmuTableAction {
+        return {
+            [unowned self] in
+            let controller = controllerGenerator($0)
+            self.navigationController?.pushViewController(controller, animated: true)
+        }
+    }
+}
+
+/// Generic view controller to present ImmuTable-based tables
+///
+/// Instead of subclassing the view controller, this is designed to be used from
+/// a "controller" class that handles all the logic, and updates the view
+/// controller, like you would update a view.
+final class ImmuTableViewController: UITableViewController, ImmuTablePresenter {
+    private lazy var handler: ImmuTableViewHandler = {
+        return ImmuTableViewHandler(takeOver: self)
+    }()
+
+    private var willAppearSubject: PublishSubject<Void> {
+        return willAppear as! PublishSubject<Void>
+    }
+
+    // MARK: - Table View Controller
+
+    init() {
+        super.init(style: .Grouped)
+    }
+
+    required init?(coder aDecoder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+
+    override func viewDidLoad() {
+        super.viewDidLoad()
+
+        WPStyleGuide.resetReadableMarginsForTableView(tableView)
+        WPStyleGuide.configureColorsForView(view, andTableView: tableView)
+    }
+
+    override func viewWillAppear(animated: Bool) {
+        super.viewWillAppear(animated)
+        willAppearSubject.onNext()
+    }
+
+    // MARK: - Inputs
+
+    /// Sets the view model for the view controller
+    func bindViewModel(viewModel: ImmuTable) {
+        handler.viewModel = viewModel
+    }
+
+    /// Registers custom rows
+    /// - seealso: ImmuTable.registerRows(_:tableView)
+    func registerRows(rows: [ImmuTableRow.Type]) {
+        ImmuTable.registerRows(rows, tableView: tableView)
+    }
+
+    // MARK: - Outputs
+
+    /// Emits a value every time viewWillAppear is called
+    let willAppear: Observable<Void> = PublishSubject()
+}