Make MeViewControllers observe changes to account

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/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/ViewRelated/MeViewController.swift

@@ -22,7 +22,6 @@ class MeViewController: UITableViewController, UIViewControllerRestoration {
     required convenience init() {
         self.init(style: .Grouped)
         let notificationCenter = NSNotificationCenter.defaultCenter()
-        notificationCenter.addObserver(self, selector: "refreshModelWithNotification:", name: WPAccountDefaultWordPressComAccountChangedNotification, object: nil)
         notificationCenter.addObserver(self, selector: "refreshModelWithNotification:", name: HelpshiftUnreadCountUpdatedNotification, object: nil)
     }
 
@@ -45,12 +44,15 @@ class MeViewController: UITableViewController, UIViewControllerRestoration {
             ], tableView: self.tableView)
 
         handler = ImmuTableViewHandler(takeOver: self)
-        reloadViewModel()
-        // FIXME: @koke 2015-12-17
-        // See https://github.com/wordpress-mobile/WordPress-iOS/issues/4416
-        // The view controller should observe changes to account details
-        // regardless of who asked for them.
-        // For now I'm just porting this to Swift as it is.
+
+        let context = ContextManager.sharedInstance().mainContext
+        let service = AccountService(managedObjectContext: context)
+        _ = service.defaultAccountChanged
+            .takeUntil(rx_deallocated)
+            .subscribeNext({ [unowned self] _ in
+                self.reloadViewModel()
+                })
+
         refreshAccountDetails()
 
         WPStyleGuide.resetReadableMarginsForTableView(tableView)
@@ -275,9 +277,7 @@ class MeViewController: UITableViewController, UIViewControllerRestoration {
         guard let account = defaultAccount() else { return }
         let context = ContextManager.sharedInstance().mainContext
         let service = AccountService(managedObjectContext: context)
-        service.updateUserDetailsForAccount(account, success: { [weak self] in
-            self?.reloadViewModel()
-            }, failure: { _ in })
+        service.updateUserDetailsForAccount(account, success: { _ in }, failure: { _ in })
     }
 
     func logOut() {

WordPress/WordPress.xcodeproj/project.pbxproj

@@ -446,6 +446,7 @@
 		E10B3652158F2D3F00419A93 /* QuartzCore.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = E10B3651158F2D3F00419A93 /* QuartzCore.framework */; };
 		E10B3654158F2D4500419A93 /* UIKit.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = E10B3653158F2D4500419A93 /* UIKit.framework */; };
 		E10B3655158F2D7800419A93 /* CoreGraphics.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 834CE7371256D0F60046A4A3 /* CoreGraphics.framework */; };
+		E10B5ACF1C4518E100F6A390 /* AccountService+Rx.swift in Sources */ = {isa = PBXBuildFile; fileRef = E10B5ACE1C4518E100F6A390 /* AccountService+Rx.swift */; };
 		E11330511A13BAA300D36D84 /* me-sites-with-jetpack.json in Resources */ = {isa = PBXBuildFile; fileRef = E11330501A13BAA300D36D84 /* me-sites-with-jetpack.json */; };
 		E114D79A153D85A800984182 /* WPError.m in Sources */ = {isa = PBXBuildFile; fileRef = E114D799153D85A800984182 /* WPError.m */; };
 		E1209FA41BB4978B00D69778 /* PeopleService.swift in Sources */ = {isa = PBXBuildFile; fileRef = E1209FA31BB4978B00D69778 /* PeopleService.swift */; };
@@ -1446,6 +1447,7 @@
 		E10675C9183FA78E00E5CE5C /* XCTest.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = XCTest.framework; path = Library/Frameworks/XCTest.framework; sourceTree = DEVELOPER_DIR; };
 		E10B3651158F2D3F00419A93 /* QuartzCore.framework */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = wrapper.framework; name = QuartzCore.framework; path = System/Library/Frameworks/QuartzCore.framework; sourceTree = SDKROOT; };
 		E10B3653158F2D4500419A93 /* UIKit.framework */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = wrapper.framework; name = UIKit.framework; path = System/Library/Frameworks/UIKit.framework; sourceTree = SDKROOT; };
+		E10B5ACE1C4518E100F6A390 /* AccountService+Rx.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = "AccountService+Rx.swift"; sourceTree = "<group>"; };
 		E11330501A13BAA300D36D84 /* me-sites-with-jetpack.json */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.json; path = "me-sites-with-jetpack.json"; sourceTree = "<group>"; };
 		E114D798153D85A800984182 /* WPError.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = WPError.h; sourceTree = "<group>"; };
 		E114D799153D85A800984182 /* WPError.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = WPError.m; sourceTree = "<group>"; };
@@ -2856,6 +2858,7 @@
 				E1209FA31BB4978B00D69778 /* PeopleService.swift */,
 				93C1147D18EC5DD500DAC95C /* AccountService.h */,
 				93C1147E18EC5DD500DAC95C /* AccountService.m */,
+				E10B5ACE1C4518E100F6A390 /* AccountService+Rx.swift */,
 				E1FD45DF1C030B3800750F4C /* AccountSettingsService.swift */,
 				93C1148318EDF6E100DAC95C /* BlogService.h */,
 				93C1148418EDF6E100DAC95C /* BlogService.m */,
@@ -4631,6 +4634,7 @@
 				5D8D53F119250412003C8859 /* BlogSelectorViewController.m in Sources */,
 				5D3D559718F88C3500782892 /* ReaderPostService.m in Sources */,
 				B532D4EE199D4418006E4DF6 /* NoteBlockImageTableViewCell.swift in Sources */,
+				E10B5ACF1C4518E100F6A390 /* AccountService+Rx.swift in Sources */,
 				93FA59DD18D88C1C001446BC /* PostCategoryService.m in Sources */,
 				5DCC4CD819A50CC0003E548C /* ReaderSite.m in Sources */,
 				93C4864F181043D700A24725 /* ActivityLogDetailViewController.m in Sources */,

WordPress/WordPressTest/AccountServiceTests.swift

@@ -1,5 +1,7 @@
 import UIKit
+import RxSwift
 import XCTest
+@testable import WordPress
 
 class AccountServiceTests: XCTestCase {
     var contextManager: TestContextManager!
@@ -84,4 +86,130 @@ class AccountServiceTests: XCTestCase {
         XCTAssertNil(accountService.defaultWordPressComAccount(), "No default account should be set")
         XCTAssertTrue(account.fault, "Account should be deleted")
     }
+
+    func testCreateAccountSetsDefaultAccount() {
+        XCTAssertNil(accountService.defaultWordPressComAccount())
+
+        let account = accountService.createOrUpdateAccountWithUsername("username", authToken: "authtoken")
+        XCTAssertEqual(accountService.defaultWordPressComAccount(), account)
+    }
+
+    func testCreateAccountDoesntReplaceDefaultAccount() {
+        XCTAssertNil(accountService.defaultWordPressComAccount())
+
+        let account = accountService.createOrUpdateAccountWithUsername("username", authToken: "authtoken")
+        XCTAssertEqual(accountService.defaultWordPressComAccount(), account)
+
+        accountService.createOrUpdateAccountWithUsername("another", authToken: "authtoken")
+        XCTAssertEqual(accountService.defaultWordPressComAccount(), account)
+    }
+
+    func testDefaultAccountObjectIDEmitsInitialValue() {
+        let currentObjectID = waitForValueIn(accountService.defaultAccountObjectID, block: {})
+
+        XCTAssertNil(currentObjectID)
+    }
+
+    func testDefaultAccountObjectIDEmitsValueWhenAccountIsSet() {
+        var createdAccount: WPAccount? = nil
+        let currentObjectID = waitForValueIn(accountService.defaultAccountObjectID, skip: 1) { [unowned self] in
+            createdAccount = self.accountService.createOrUpdateAccountWithUsername("username", authToken: "authtoken")
+        }
+        guard let account = createdAccount else {
+            XCTFail("account should not be nil")
+            return
+        }
+
+        XCTAssertEqual(currentObjectID, account.objectID)
+    }
+
+    func testDefaultAccountObjectIDEmitsValueWhenAccointIsRemoved() {
+        let currentObjectID = waitForValueIn(accountService.defaultAccountObjectID, skip: 2) { [unowned self] in
+            self.accountService.createOrUpdateAccountWithUsername("username", authToken: "authtoken")
+            self.accountService.removeDefaultWordPressComAccount()
+        }
+        XCTAssertNil(currentObjectID)
+    }
+
+    func testDefaultAccountChangedEmitsInitialValue() {
+        let value = waitForValueIn(accountService.defaultAccountChanged, block: {})
+
+        XCTAssertNil(value)
+    }
+
+    func testDefaultAccountChangedEmitsValueWhenPropertyIsChanged() {
+        let value = waitForValueIn(accountService.defaultAccountChanged, skip: 2) { [unowned self] in
+            // Emits initial nil (1)
+            // Emits account (2)
+            let account = self.accountService.createOrUpdateAccountWithUsername("jack", authToken: "authtoken")
+
+            // Emits account (3)
+            account.email = "jack@sparrow.com"
+            self.contextManager.saveContextAndWait(self.accountService.managedObjectContext)
+        }
+
+        XCTAssertNotNil(value)
+        XCTAssertEqual(value?.email, "jack@sparrow.com")
+        XCTAssertNil(value?.displayName)
+    }
+
+    func testDefaultAccountChangedEmitsValueWhenPropertyIsChangedAfterAnotherAccountChanges() {
+        let value = waitForValueIn(accountService.defaultAccountChanged, skip: 3) { [unowned self] in
+            // Emits initial nil (1)
+            // Emits account (2)
+            let account = self.accountService.createOrUpdateAccountWithUsername("jack", authToken: "authtoken")
+
+            // Emits account (3)
+            account.email = "jack@sparrow.com"
+            self.contextManager.saveContextAndWait(self.accountService.managedObjectContext)
+
+            // Doesn't emit (3)
+            let another = self.accountService.createOrUpdateAccountWithUsername("elizabeth", authToken: "authtoken2")
+            another.displayName = "Elizabeth Swann"
+            self.contextManager.saveContextAndWait(self.accountService.managedObjectContext)
+
+            // Emits account (4)
+            account.displayName = "Jack Sparrow"
+            self.contextManager.saveContextAndWait(self.accountService.managedObjectContext)
+        }
+
+        XCTAssertNotNil(value)
+        XCTAssertEqual(value?.email, "jack@sparrow.com")
+        XCTAssertEqual(value?.displayName, "Jack Sparrow")
+    }
+
+    func testDefaultAccountChangedEmitsValueAfterAccountIsRemoved() {
+        let value = waitForValueIn(accountService.defaultAccountChanged, skip: 2) { [unowned self] in
+            // Emits initial nil (1)
+            // Emits account (2)
+            self.accountService.createOrUpdateAccountWithUsername("jack", authToken: "authtoken")
+
+            // Emits nil (3)
+            self.accountService.removeDefaultWordPressComAccount()
+        }
+
+        XCTAssertNil(value)
+    }
+
+    private func waitForValueIn<T>(observable: Observable<T>, skip: Int = 0, block: () -> Void) -> T {
+        var result: T? = nil
+        let expectation = expectationWithDescription("Observable completed \(observable)")
+        let subscription = observable.skip(skip).take(1).subscribe { (event) -> Void in
+            switch event {
+            case .Next(let value):
+                result = value
+            case .Error(let error):
+                XCTFail("Observable emitted error \(error)")
+            case .Completed:
+                expectation.fulfill()
+            }
+        }
+
+        block()
+
+        waitForExpectationsWithTimeout(5) { _ in
+            subscription.dispose()
+        }
+        return result!
+    }
 }