refactor data sources to not have a shared base class

firebase · Feb 10, 2017 · 01d8bb0 · 01d8bb0
1 parent 0b1fd5c
commit 01d8bb0
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Showing 9 changed files with 105 additions and 36 deletions.
diff --git a/FirebaseDatabaseUI/FUICollectionViewDataSource.h b/FirebaseDatabaseUI/FUICollectionViewDataSource.h
@@ -41,16 +41,26 @@ NS_ASSUME_NONNULL_BEGIN
 @property (nonatomic, readwrite, weak, nullable) UICollectionView *collectionView;
 
 /**
- * The callback to populate a subclass of UICollectionViewCell with an object
- * provided by the datasource.
+ * The number of items in the data source.
  */
-@property (strong, nonatomic, readonly) UICollectionViewCell *(^populateCellAtIndexPath)
-  (UICollectionView *collectionView, NSIndexPath *indexPath, FIRDataSnapshot *object);
+@property (nonatomic, readonly) NSUInteger count;
 
 /**
- * The number of items in the data source.
+ * The snapshots in the data source.
  */
-@property (nonatomic, readonly) NSUInteger count;
+@property (nonatomic, readonly) NSArray<FIRDataSnapshot *> *items;
+
+/**
+ * A closure that should be invoked when the query encounters a fatal error. 
+ * After this is invoked, the query is no longer valid and the data source should
+ * be recreated.
+ */
+@property (nonatomic, copy, readwrite) void (^queryErrorHandler)(NSError *);
+
+/**
+ * Returns the snapshot at the given index. Throws an exception if the index is out of bounds.
+ */
+- (FIRDataSnapshot *)snapshotAtIndex:(NSInteger)index;
 
 /**
  * Initialize an instance of FUICollectionViewDataSource that populates

diff --git a/FirebaseDatabaseUI/FUICollectionViewDataSource.m b/FirebaseDatabaseUI/FUICollectionViewDataSource.m
@@ -23,10 +23,17 @@
 
 @import FirebaseDatabase;
 
-@interface FUICollectionViewDataSource ()
+@interface FUICollectionViewDataSource () <FUICollectionDelegate>
 
 @property (nonatomic, readonly, nonnull) id<FUICollection> collection;
 
+/**
+ * The callback to populate a subclass of UICollectionViewCell with an object
+ * provided by the datasource.
+ */
+@property (strong, nonatomic, readonly) UICollectionViewCell *(^populateCellAtIndexPath)
+  (UICollectionView *collectionView, NSIndexPath *indexPath, FIRDataSnapshot *object);
+
 @end
 
 @implementation FUICollectionViewDataSource
@@ -40,6 +47,7 @@ - (instancetype)initWithCollection:(id<FUICollection>)collection
   self = [super init];
   if (self) {
     _collection = collection;
+    _collection.delegate = self;
     _populateCellAtIndexPath = populateCell;
   }
   return self;
@@ -57,6 +65,14 @@ - (NSUInteger)count {
   return self.collection.count;
 }
 
+- (NSArray<FIRDataSnapshot *> *)items {
+  return self.collection.items;
+}
+
+- (FIRDataSnapshot *)snapshotAtIndex:(NSInteger)index {
+  return [self.collection snapshotAtIndex:index];
+}
+
 - (void)bindToView:(UICollectionView *)view {
   self.collectionView = view;
   view.dataSource = self;
@@ -92,6 +108,12 @@ - (void)array:(FUIArray *)array didMoveObject:(id)object
                                toIndexPath:[NSIndexPath indexPathForItem:toIndex inSection:0]];
 }
 
+- (void)array:(id<FUICollection>)array queryCancelledWithError:(NSError *)error {
+  if (self.queryErrorHandler != NULL) {
+    self.queryErrorHandler(error);
+  }
+}
+
 #pragma mark - UICollectionViewDataSource methods
 
 - (nonnull UICollectionViewCell *)collectionView:(nonnull UICollectionView *)collectionView

diff --git a/FirebaseDatabaseUI/FUITableViewDataSource.h b/FirebaseDatabaseUI/FUITableViewDataSource.h
@@ -42,15 +42,26 @@ NS_ASSUME_NONNULL_BEGIN
 @property (nonatomic, readwrite, weak, nullable) UITableView *tableView;
 
 /**
- * The callback used by the data source to populate the table view.
+ * The number of items in the data source.
  */
-@property (strong, nonatomic, readonly) UITableViewCell *(^populateCell)
-  (UITableView *tableView, NSIndexPath *indexPath, FIRDataSnapshot *snap);
+@property (nonatomic, readonly) NSUInteger count;
 
 /**
- * The number of items in the data source.
+ * The snapshots in the data source.
  */
-@property (nonatomic, readonly) NSUInteger count;
+@property (nonatomic, readonly) NSArray<FIRDataSnapshot *> *items;
+
+/**
+ * A closure that should be invoked when the query encounters a fatal error.
+ * After this is invoked, the query is no longer valid and the data source should
+ * be recreated.
+ */
+@property (nonatomic, copy, readwrite) void (^queryErrorHandler)(NSError *);
+
+/**
+ * Returns the snapshot at the given index. Throws an exception if the index is out of bounds.
+ */
+- (FIRDataSnapshot *)snapshotAtIndex:(NSInteger)index;
 
 /**
  * Initialize an instance of FUITableViewDataSource.

diff --git a/FirebaseDatabaseUI/FUITableViewDataSource.m b/FirebaseDatabaseUI/FUITableViewDataSource.m
@@ -23,7 +23,7 @@
 
 @import FirebaseDatabase;
 
-@interface FUITableViewDataSource ()
+@interface FUITableViewDataSource () <FUICollectionDelegate>
 
 @property (strong, nonatomic, readwrite) UITableViewCell *(^populateCell)
   (UITableView *tableView, NSIndexPath *indexPath, FIRDataSnapshot *snap);
@@ -43,6 +43,7 @@ - (instancetype)initWithCollection:(id<FUICollection>)collection
   self = [super init];
   if (self != nil) {
     _collection = collection;
+    _collection.delegate = self;
     _populateCell = populateCell;
   }
   return self;
@@ -60,6 +61,14 @@ - (NSUInteger)count {
   return self.collection.count;
 }
 
+- (NSArray<FIRDataSnapshot *> *)items {
+  return self.collection.items;
+}
+
+- (FIRDataSnapshot *)snapshotAtIndex:(NSInteger)index {
+  return [self.collection snapshotAtIndex:index];
+}
+
 - (void)bindToView:(UITableView *)view {
   self.tableView = view;
   view.dataSource = self;
@@ -103,6 +112,12 @@ - (void)array:(FUIArray *)array didMoveObject:(id)object
                          toIndexPath:[NSIndexPath indexPathForRow:toIndex inSection:0]];
 }
 
+- (void)array:(id<FUICollection>)array queryCancelledWithError:(NSError *)error {
+  if (self.queryErrorHandler != NULL) {
+    self.queryErrorHandler(error);
+  }
+}
+
 #pragma mark - UITableViewDataSource methods
 
 - (id)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

diff --git a/FirebaseDatabaseUITests/FUICollectionViewDataSourceTest.m b/FirebaseDatabaseUITests/FUICollectionViewDataSourceTest.m
@@ -55,6 +55,9 @@ - (void)setUp {
     return cell;
   }];
 
+  // Removing this line causes the tests to crash.
+  NSLog(@"%lu", (unsigned long)[self.collectionView numberOfItemsInSection:0]);
+
   [self.observable populateWithCount:10];
 }
 
@@ -70,6 +73,11 @@ - (void)testItHasACount {
   XCTAssert(count == 10, @"expected data source to have 10 elements after 10 insertions, but got %lu", count);
 }
 
+- (void)testItReturnsSnapshots {
+  id snap = [self.dataSource snapshotAtIndex:0];
+  XCTAssert(snap != nil, @"expected snapshot to exist");
+}
+
 - (void)testItPopulatesCells {
   UICollectionViewCell *cell = [self.dataSource collectionView:self.collectionView
                                         cellForItemAtIndexPath:[NSIndexPath indexPathForItem:0 inSection:0]];

diff --git a/FirebaseDatabaseUITests/FUITableViewDataSourceTest.m b/FirebaseDatabaseUITests/FUITableViewDataSourceTest.m
@@ -67,6 +67,11 @@ - (void)testItHasACount {
   XCTAssert(count == 10, @"expected data source to have 10 elements after 10 insertions, but got %lu", count);
 }
 
+- (void)testItReturnsSnapshots {
+  id snap = [self.dataSource snapshotAtIndex:0];
+  XCTAssert(snap != nil, @"expected snapshot to exist");
+}
+
 - (void)testItPopulatesCells {
   UITableViewCell *cell = [self.dataSource tableView:self.tableView
                                cellForRowAtIndexPath:[NSIndexPath indexPathForRow:5 inSection:0]];

diff --git a/FirebaseUI.podspec b/FirebaseUI.podspec
@@ -1,10 +1,10 @@
 Pod::Spec.new do |s|
   s.name         = 'FirebaseUI'
-  s.version      = '2.0.3'
+  s.version      = '3.0.0'
   s.summary      = 'UI binding libraries for Firebase.'
   s.homepage     = 'https://github.com/firebase/FirebaseUI-iOS'
   s.license      = { :type => 'Apache 2.0', :file => 'FirebaseUIFrameworks/LICENSE' }
-  s.source       = { :http => 'https://github.com/firebase/FirebaseUI-iOS/releases/download/v2.0.3/FirebaseUIFrameworks.zip' }
+  s.source       = { :http => 'https://github.com/firebase/FirebaseUI-iOS/releases/download/v3.0.0/FirebaseUIFrameworks.zip' }
   s.author       = 'Firebase'
   s.platform = :ios
   s.ios.deployment_target = '8.0'

diff --git a/samples/swift/FirebaseUI-demo-swift/Samples/Chat/ChatViewController.swift b/samples/swift/FirebaseUI-demo-swift/Samples/Chat/ChatViewController.swift
@@ -62,18 +62,15 @@ class ChatViewController: UIViewController, UICollectionViewDelegateFlowLayout {
       self.query = self.chatReference.queryLimited(toLast: 50)
 
       self.collectionViewDataSource =
-        FUICollectionViewDataSource(query: self.query!,
-                                    view: self.collectionView,
-                                    populateCell: { (view, indexPath, snap) -> UICollectionViewCell in
-        let cell = view.dequeueReusableCell(withReuseIdentifier: ChatViewController.reuseIdentifier,
-                                            for: indexPath) as! ChatCollectionViewCell
-        let chat = Chat(snapshot: snap)!
-        cell.populateCellWithChat(chat, user: self.user, maxWidth: self.view.frame.size.width)
-        return cell
-      })
-      self.collectionView.dataSource = self.collectionViewDataSource
+          self.collectionView.bind(to: self.query!) { (view, indexPath, snap) -> UICollectionViewCell in
+            let cell = view.dequeueReusableCell(withReuseIdentifier: ChatViewController.reuseIdentifier,
+                                                for: indexPath) as! ChatCollectionViewCell
+            let chat = Chat(snapshot: snap)!
+            cell.populateCellWithChat(chat, user: self.user, maxWidth: self.view.frame.size.width)
+            return cell
+      }
 
-      // FirebaseArray has a delegate method `childAdded` that could be used here,
+      // FUIArray has a delegate method `childAdded` that could be used here,
       // but unfortunately FirebaseCollectionViewDataSource uses the FUICollection
       // delegate methods to update its own internal state, so in order to scroll
       // on new insertions we still need to use the query directly.
@@ -94,13 +91,13 @@ class ChatViewController: UIViewController, UICollectionViewDelegateFlowLayout {
 
     // Notification boilerplate to handle keyboard appearance/disappearance
     NotificationCenter.default.addObserver(self,
-                                                     selector: #selector(keyboardWillShow),
-                                                     name: NSNotification.Name.UIKeyboardWillShow,
-                                                     object: nil)
+                                           selector: #selector(keyboardWillShow),
+                                           name: NSNotification.Name.UIKeyboardWillShow,
+                                           object: nil)
     NotificationCenter.default.addObserver(self,
-                                                     selector: #selector(keyboardWillHide),
-                                                     name: NSNotification.Name.UIKeyboardWillHide,
-                                                     object: nil)
+                                           selector: #selector(keyboardWillHide),
+                                           name: NSNotification.Name.UIKeyboardWillHide,
+                                           object: nil)
   }
 
   @objc fileprivate func didTapSend(_ sender: AnyObject) {
@@ -174,8 +171,9 @@ class ChatViewController: UIViewController, UICollectionViewDelegateFlowLayout {
   }
 
   fileprivate func scrollToBottom(animated: Bool) {
-    let count = self.collectionViewDataSource.collectionView(self.collectionView, numberOfItemsInSection: 0)
-    let indexPath = IndexPath(row: count - 1, section: 0)
+    let count = Int(self.collectionViewDataSource.count)
+    guard count > 0 else { return }
+    let indexPath = IndexPath(item: count - 1, section: 0)
     self.collectionView.scrollToItem(at: indexPath, at: .bottom, animated: animated)
   }
 
@@ -186,7 +184,7 @@ class ChatViewController: UIViewController, UICollectionViewDelegateFlowLayout {
     let heightPadding: CGFloat = 16
 
     let width = self.view.frame.size.width
-    let blob = self.collectionViewDataSource.object(at: UInt((indexPath as NSIndexPath).row))!
+    let blob = self.collectionViewDataSource.snapshot(at: indexPath.item)
     let text = Chat(snapshot: blob)!.text
 
     let rect = ChatCollectionViewCell.boundingRectForText(text, maxWidth: width)

diff --git a/samples/swift/Podfile b/samples/swift/Podfile
@@ -1,7 +1,7 @@
 target 'FirebaseUI-demo-swift' do
   use_frameworks!
 
-  pod 'FirebaseUI', :podspec => 'https://raw.githubusercontent.com/firebase/FirebaseUI-iOS/master/FirebaseUI.podspec'
+  pod 'FirebaseUI', :podspec => '../../FirebaseUI.podspec'
 
   target 'FirebaseUI-demo-swiftTests' do
     inherit! :search_paths