From 8eb363d9982e8bc15b459fdd5e23f5d1248a1a54 Mon Sep 17 00:00:00 2001
From: Morgan Chen <morganchen12@gmail.com>
Date: Wed, 19 Oct 2016 16:57:17 -0700
Subject: [PATCH 1/4] remove cell registration and creation from collection
 view data source

---
 FirebaseDatabaseUI/FirebaseArray.h            |   2 +-
 .../FirebaseCollectionViewDataSource.h        | 348 +-----------------
 .../FirebaseCollectionViewDataSource.m        | 245 +-----------
 3 files changed, 19 insertions(+), 576 deletions(-)

diff --git a/FirebaseDatabaseUI/FirebaseArray.h b/FirebaseDatabaseUI/FirebaseArray.h
index 2cb32ea37a3..59c40259dce 100644
--- a/FirebaseDatabaseUI/FirebaseArray.h
+++ b/FirebaseDatabaseUI/FirebaseArray.h
@@ -47,7 +47,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 /**
  * The delegate object that array changes are surfaced to, which conforms to the
- * [FirebaseArrayDelegate Protocol](FirebaseArrayDelegate).
+ * @c FirebaseArrayDelegate protocol.
  */
 @property(weak, nonatomic, nullable) id<FirebaseArrayDelegate> delegate;
 
diff --git a/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.h b/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.h
index 228f4ff16d4..76eb65c47d0 100644
--- a/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.h
+++ b/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.h
@@ -46,203 +46,19 @@ NS_ASSUME_NONNULL_BEGIN
  */
 @interface FirebaseCollectionViewDataSource : FirebaseDataSource<UICollectionViewDataSource>
 
-/**
- * The model class to coerce FIRDataSnapshots to (if desired). For instance, if
- * the modelClass is set
- * to [Message class] in Obj-C or Message.self in Swift, then objects of type
- * Message will be
- * returned instead of type FIRDataSnapshot.
- * Defaults to FIRDataSnapshot.
- */
-@property(strong, nonatomic, null_resettable) Class modelClass;
-
-/**
- * The cell class to coerce UICollectionViewCells to (if desired). For instance,
- * if the cellClass is
- * set to [CustomCollectionViewCell class] in Obj-C or CustomCollectionViewCell
- * in Swift, then
- * objects of type CustomCollectionViewCell will be returned instead of type
- * UICollectionViewCell.
- * Defaults to UICollectionViewCell.
- */
-@property(strong, nonatomic, null_resettable) Class cellClass;
-
-/**
- * The reuse identifier for cells in the UICollectionView.
- */
-@property(strong, nonatomic) NSString *reuseIdentifier;
-
 /**
  * The UICollectionView instance that operations (inserts, removals, moves,
- * etc.) are performed
- * against.
+ * etc.) are performed against. The data source does not claim ownership of
+ * the collection view it populates.
  */
-@property(strong, nonatomic) UICollectionView *collectionView;
-
-/**
- * Property to keep track of prototype cell use, to not register a class for the
- * UICollectionView or
- * do similar book keeping.
- */
-@property BOOL hasPrototypeCell;
+@property (nonatomic, readonly, weak) UICollectionView *collectionView;
 
 /**
  * The callback to populate a subclass of UICollectionViewCell with an object
- * provided by the
- * datasource.
- */
-@property(strong, nonatomic, readonly) void (^populateCell)
-    (__kindof UICollectionViewCell *cell, __kindof NSObject *object);
-
-/**
- * Initialize an instance of FirebaseCollectionViewDataSource that populates
- * UICollectionViewCells
- * with FIRDataSnapshots.
- * @param ref A Firebase reference to bind the datasource to
- * @param identifier A string to use as a CellReuseIdentifier
- * @param collectionView An instance of a UICollectionView to bind to
- * @return An instance of FirebaseCollectionViewDataSource that populates
- * UICollectionViewCells with
- * FIRDataSnapshots
- */
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-        cellReuseIdentifier:(NSString *)identifier
-                       view:(UICollectionView *)collectionView;
-
-/**
- * Initialize an instance of FirebaseCollectionViewDataSource that populates
- * UICollectionViewCells
- * with FIRDataSnapshots. Note that this method is used when using prototype
- * cells, where the cells
- * don't need to be registered in the class.
- * @param ref A Firebase reference to bind the datasource to
- * @param identifier A string to use as a CellReuseIdentifier
- * @param collectionView An instance of a UICollectionView to bind to
- * @return An instance of FirebaseCollectionViewDataSource that populates
- * UICollectionViewCells with
- * FIRDataSnapshots
- */
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-   prototypeReuseIdentifier:(NSString *)identifier
-                       view:(UICollectionView *)collectionView;
-
-/**
- * Initialize an instance of FirebaseCollectionViewDataSource that populates a
- * custom subclass of
- * UICollectionViewCell with FIRDataSnapshots.
- * @param ref A Firebase reference to bind the datasource to
- * @param cell A subclass of UICollectionViewCell used to populate the
- * UICollectionView, defaults to
- * UICollectionViewCell if nil
- * @param identifier A string to use as a CellReuseIdentifier
- * @param collectionView An instance of a UICollectionView to bind to
- * @return An instance of FirebaseCollectionViewDataSource that populates a
- * custom subclass of
- * UICollectionViewCell with FIRDataSnapshots
- */
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-                  cellClass:(nullable Class)cell
-        cellReuseIdentifier:(NSString *)identifier
-                       view:(UICollectionView *)collectionView;
-
-/**
- * Initialize an instance of FirebaseCollectionViewDataSource that populates a
- * custom xib with
- * FIRDataSnapshots.
- * @param ref A Firebase reference to bind the datasource to
- * @param nibName The name of a xib file to create the layout for a
- * UICollectionViewCell
- * @param identifier A string to use as a CellReuseIdentifier
- * @param collectionView An instance of a UICollectionView to bind to
- * @return An instance of FirebaseCollectionViewDataSource that populates a
- * custom xib with
- * FIRDataSnapshots
- */
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-                   nibNamed:(NSString *)nibName
-        cellReuseIdentifier:(NSString *)identifier
-                       view:(UICollectionView *)collectionView;
-
-/**
- * Initialize an instance of FirebaseCollectionViewDataSource that populates
- * UICollectionViewCells
- * with a custom model class.
- * @param ref A Firebase reference to bind the datasource to
- * @param model A custom class that FIRDataSnapshots are coerced to, defaults to
- * FIRDataSnapshot if nil
- * @param identifier A string to use as a CellReuseIdentifier
- * @param collectionView An instance of a UICollectionView to bind to
- * @return An instance of FirebaseCollectionViewDataSource that populates
- * UICollectionViewCells with
- * a custom model class
- */
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-                 modelClass:(nullable Class)model
-        cellReuseIdentifier:(NSString *)identifier
-                       view:(UICollectionView *)collectionView;
-
-/**
- * Initialize an instance of FirebaseCollectionViewDataSource that populates
- * UICollectionViewCells
- * with a custom model class. Note that this method is used when using prototype
- * cells, where the
- * cells don't need to be registered in the class.
- * @param ref A Firebase reference to bind the datasource to
- * @param model A custom class that FIRDataSnapshots are coerced to, defaults to
- * FIRDataSnapshot if nil
- * @param identifier A string to use as a CellReuseIdentifier
- * @param collectionView An instance of a UICollectionView to bind to
- * @return An instance of FirebaseCollectionViewDataSource that populates
- * UICollectionViewCells with
- * a custom model class
- */
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-                 modelClass:(nullable Class)model
-   prototypeReuseIdentifier:(NSString *)identifier
-                       view:(UICollectionView *)collectionView;
-
-/**
- * Initialize an instance of FirebaseCollectionViewDataSource that populates a
- * custom subclass of
- * UICollectionViewCell with a custom model class.
- * @param ref A Firebase reference to bind the datasource to
- * @param model A custom class that FIRDataSnapshots are coerced to, defaults to
- * FIRDataSnapshot if nil
- * @param cell A subclass of UICollectionViewCell used to populate the
- * UICollectionView, defaults to
- * UICollectionViewCell if nil
- * @param identifier A string to use as a CellReuseIdentifier
- * @param collectionView An instance of a UICollectionView to bind to
- * @return An instance of FirebaseCollectionViewDataSource that populates a
- * custom subclass of
- * UICollectionViewCell with a custom model class
- */
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-                 modelClass:(nullable Class)model
-                  cellClass:(nullable Class)cell
-        cellReuseIdentifier:(NSString *)identifier
-                       view:(UICollectionView *)collectionView;
-
-/**
- * Initialize an instance of FirebaseCollectionViewDataSource that populates a
- * custom xib with a
- * custom model class.
- * @param ref A Firebase reference to bind the datasource to
- * @param model A custom class that FIRDataSnapshots are coerced to, defaults to
- * FIRDataSnapshot if nil
- * @param nibName The name of a xib file to create the layout for a
- * UICollectionViewCell
- * @param identifier A string to use as a CellReuseIdentifier
- * @param collectionView An instance of a UICollectionView to bind to
- * @return An instance of FirebaseCollectionViewDataSource that populates a
- * custom xib with a custom
- * model class
+ * provided by the datasource.
  */
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-                 modelClass:(nullable Class)model
-                   nibNamed:(NSString *)nibName
-        cellReuseIdentifier:(NSString *)identifier
-                       view:(UICollectionView *)collectionView;
+@property(strong, nonatomic, readonly) UICollectionViewCell *(^populateCellAtIndexPath)
+  (NSIndexPath *indexPath, UICollectionView *collectionView, FIRDataSnapshot *object);
 
 /**
  * Initialize an instance of FirebaseCollectionViewDataSource that populates
@@ -256,154 +72,10 @@ NS_ASSUME_NONNULL_BEGIN
  * FIRDataSnapshots
  */
 - (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-          cellReuseIdentifier:(NSString *)identifier
-                         view:(UICollectionView *)collectionView;
-
-/**
- * Initialize an instance of FirebaseCollectionViewDataSource that populates
- * UICollectionViewCells
- * with FIRDataSnapshots. Note that this method is used when using prototype
- * cells, where the cells
- * don't need to be registered in the class.
- * @param query A Firebase query to bind the datasource to
- * @param identifier A string to use as a CellReuseIdentifier
- * @param collectionView An instance of a UICollectionView to bind to
- * @return An instance of FirebaseCollectionViewDataSource that populates
- * UICollectionViewCells with
- * FIRDataSnapshots
- */
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-     prototypeReuseIdentifier:(NSString *)identifier
-                         view:(UICollectionView *)collectionView;
-
-/**
- * Initialize an instance of FirebaseCollectionViewDataSource that populates a
- * custom subclass of
- * UICollectionViewCell with FIRDataSnapshots.
- * @param query A Firebase query to bind the datasource to
- * @param cell A subclass of UICollectionViewCell used to populate the
- * UICollectionView, defaults to
- * UICollectionViewCell if nil
- * @param identifier A string to use as a CellReuseIdentifier
- * @param collectionView An instance of a UICollectionView to bind to
- * @return An instance of FirebaseCollectionViewDataSource that populates a
- * custom subclass of
- * UICollectionViewCell with FIRDataSnapshots
- */
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-                    cellClass:(nullable Class)cell
-          cellReuseIdentifier:(NSString *)identifier
-                         view:(UICollectionView *)collectionView;
-
-/**
- * Initialize an instance of FirebaseCollectionViewDataSource that populates a
- * custom xib with
- * FIRDataSnapshots.
- * @param query A Firebase query to bind the datasource to
- * @param nibName The name of a xib file to create the layout for a
- * UICollectionViewCell
- * @param identifier A string to use as a CellReuseIdentifier
- * @param collectionView An instance of a UICollectionView to bind to
- * @return An instance of FirebaseCollectionViewDataSource that populates a
- * custom xib with
- * FIRDataSnapshots
- */
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-                     nibNamed:(NSString *)nibName
-          cellReuseIdentifier:(NSString *)identifier
-                         view:(UICollectionView *)collectionView;
-
-/**
- * Initialize an instance of FirebaseCollectionViewDataSource that populates
- * UICollectionViewCells
- * with a custom model class.
- * @param query A Firebase query to bind the datasource to
- * @param model A custom class that FIRDataSnapshots are coerced to, defaults to
- * FIRDataSnapshot if nil
- * @param identifier A string to use as a CellReuseIdentifier
- * @param collectionView An instance of a UICollectionView to bind to
- * @return An instance of FirebaseCollectionViewDataSource that populates
- * UICollectionViewCells with
- * a custom model class
- */
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-                   modelClass:(nullable Class)model
-          cellReuseIdentifier:(NSString *)identifier
-                         view:(UICollectionView *)collectionView;
-
-/**
- * Initialize an instance of FirebaseCollectionViewDataSource that populates
- * UICollectionViewCells
- * with a custom model class. Note that this method is used when using prototype
- * cells, where the
- * cells don't need to be registered in the class.
- * @param query A Firebase query to bind the datasource to
- * @param model A custom class that FIRDataSnapshots are coerced to, defaults to
- * FIRDataSnapshot if nil
- * @param identifier A string to use as a CellReuseIdentifier
- * @param collectionView An instance of a UICollectionView to bind to
- * @return An instance of FirebaseCollectionViewDataSource that populates
- * UICollectionViewCells with
- * a custom model class
- */
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-                   modelClass:(nullable Class)model
-     prototypeReuseIdentifier:(NSString *)identifier
-                         view:(UICollectionView *)collectionView;
-
-/**
- * Initialize an instance of FirebaseCollectionViewDataSource that populates a
- * custom subclass of
- * UICollectionViewCell with a custom model class.
- * @param query A Firebase query to bind the datasource to
- * @param model A custom class that FIRDataSnapshots are coerced to, defaults to
- * FIRDataSnapshot if nil
- * @param cell A subclass of UICollectionViewCell used to populate the
- * UICollectionView, defaults to
- * UICollectionViewCell if nil
- * @param identifier A string to use as a CellReuseIdentifier
- * @param collectionView An instance of a UICollectionView to bind to
- * @return An instance of FirebaseCollectionViewDataSource that populates a
- * custom subclass of
- * UICollectionViewCell with a custom model class
- */
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-                   modelClass:(nullable Class)model
-                    cellClass:(nullable Class)cell
-          cellReuseIdentifier:(NSString *)identifier
-                         view:(UICollectionView *)collectionView;
-
-/**
- * Initialize an instance of FirebaseCollectionViewDataSource that populates a
- * custom xib with a
- * custom model class.
- * @param query A Firebase query to bind the datasource to
- * @param model A custom class that FIRDataSnapshots are coerced to, defaults to
- * FIRDataSnapshot if nil
- * @param nibName The name of a xib file to create the layout for a
- * UICollectionViewCell
- * @param identifier A string to use as a CellReuseIdentifier
- * @param collectionView An instance of a UICollectionView to bind to
- * @return An instance of FirebaseCollectionViewDataSource that populates a
- * custom xib with a custom
- * model class
- */
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-                   modelClass:(nullable Class)model
-                     nibNamed:(NSString *)nibName
-          cellReuseIdentifier:(NSString *)identifier
-                         view:(UICollectionView *)collectionView;
-
-/**
- * This method populates the fields of a UICollectionViewCell or subclass given
- * an FIRDataSnapshot (or
- * custom model object).
- * @param callback A block which returns an initialized UICollectionViewCell (or
- * subclass) and the
- * corresponding object to populate the cell with.
- */
-- (void)populateCellWithBlock:(void (^)(__kindof UICollectionViewCell *cell,
-                                        __kindof NSObject *object))callback;
+                         view:(UICollectionView *)collectionView
+                 populateCell:(UICollectionViewCell * (^)(NSIndexPath *indexPath,
+                                                          UICollectionView *collectionView,
+                                                          FIRDataSnapshot *object))populateCell;
 
 @end
 
diff --git a/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.m b/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.m
index 8c10cebc6b9..94bbab38fee 100644
--- a/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.m
+++ b/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.m
@@ -22,216 +22,20 @@
 
 @import FirebaseDatabase;
 
-@interface FirebaseCollectionViewDataSource ()
-@property(strong, nonatomic, readwrite) void (^populateCell)
-(__kindof UICollectionViewCell *cell, __kindof NSObject *object);
-@end
-
 @implementation FirebaseCollectionViewDataSource
 
 #pragma mark - FirebaseDataSource initializer methods
 
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-        cellReuseIdentifier:(NSString *)identifier
-                       view:(UICollectionView *)collectionView {
-  return [self initWithQuery:ref
-                  modelClass:nil
-                   cellClass:nil
-         cellReuseIdentifier:identifier
-                        view:collectionView];
-}
-
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-   prototypeReuseIdentifier:(NSString *)identifier
-                       view:(UICollectionView *)collectionView {
-  return [self initWithQuery:ref
-                    modelClass:nil
-      prototypeReuseIdentifier:identifier
-                          view:collectionView];
-}
-
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-                  cellClass:(Class)cell
-        cellReuseIdentifier:(NSString *)identifier
-                       view:(UICollectionView *)collectionView {
-  return [self initWithQuery:ref
-                  modelClass:nil
-                   cellClass:cell
-         cellReuseIdentifier:identifier
-                        view:collectionView];
-}
-
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-                   nibNamed:(NSString *)nibName
-        cellReuseIdentifier:(NSString *)identifier
-                       view:(UICollectionView *)collectionView {
-  return [self initWithQuery:ref
-                  modelClass:nil
-                    nibNamed:nibName
-         cellReuseIdentifier:identifier
-                        view:collectionView];
-}
-
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-                 modelClass:(Class)model
-        cellReuseIdentifier:(NSString *)identifier
-                       view:(UICollectionView *)collectionView {
-  return [self initWithQuery:ref
-                  modelClass:model
-                   cellClass:nil
-         cellReuseIdentifier:identifier
-                        view:collectionView];
-}
-
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-                 modelClass:(Class)model
-   prototypeReuseIdentifier:(NSString *)identifier
-                       view:(UICollectionView *)collectionView {
-  return [self initWithQuery:ref
-                  modelClass:model
-    prototypeReuseIdentifier:identifier
-                        view:collectionView];
-}
-
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-                 modelClass:(Class)model
-                  cellClass:(Class)cell
-        cellReuseIdentifier:(NSString *)identifier
-                       view:(UICollectionView *)collectionView {
-  return [self initWithQuery:ref
-                  modelClass:model
-                   cellClass:cell
-         cellReuseIdentifier:identifier
-                        view:collectionView];
-}
-
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-                 modelClass:(Class)model
-                   nibNamed:(NSString *)nibName
-        cellReuseIdentifier:(NSString *)identifier
-                       view:(UICollectionView *)collectionView {
-  return [self initWithQuery:ref
-                  modelClass:model
-                    nibNamed:nibName
-         cellReuseIdentifier:identifier
-                        view:collectionView];
-}
-
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-          cellReuseIdentifier:(NSString *)identifier
-                         view:(UICollectionView *)collectionView {
-  return [self initWithQuery:query
-                  modelClass:nil
-                   cellClass:nil
-         cellReuseIdentifier:identifier
-                        view:collectionView];
-}
-
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-     prototypeReuseIdentifier:(NSString *)identifier
-                         view:(UICollectionView *)collectionView {
-  self.hasPrototypeCell = YES;
-  return [self initWithQuery:query
-                  modelClass:nil
-                   cellClass:nil
-         cellReuseIdentifier:identifier
-                        view:collectionView];
-}
-
 - (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-                    cellClass:(Class)cell
-          cellReuseIdentifier:(NSString *)identifier
-                         view:(UICollectionView *)collectionView {
-  return [self initWithQuery:query
-                  modelClass:nil
-                   cellClass:cell
-         cellReuseIdentifier:identifier
-                        view:collectionView];
-}
-
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-                     nibNamed:(NSString *)nibName
-          cellReuseIdentifier:(NSString *)identifier
-                         view:(UICollectionView *)collectionView {
-  return [self initWithQuery:query
-                  modelClass:nil
-                    nibNamed:nibName
-         cellReuseIdentifier:identifier
-                        view:collectionView];
-}
-
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-                   modelClass:(Class)model
-          cellReuseIdentifier:(NSString *)identifier
-                         view:(UICollectionView *)collectionView {
-  return [self initWithQuery:query
-                  modelClass:model
-                   cellClass:nil
-         cellReuseIdentifier:identifier
-                        view:collectionView];
-}
-
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-                   modelClass:(Class)model
-     prototypeReuseIdentifier:(NSString *)identifier
-                         view:(UICollectionView *)collectionView {
-  self.hasPrototypeCell = YES;
-  return [self initWithQuery:query
-                  modelClass:model
-                   cellClass:nil
-         cellReuseIdentifier:identifier
-                        view:collectionView];
-}
-
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-                   modelClass:(Class)model
-                    cellClass:(Class)cell
-          cellReuseIdentifier:(NSString *)identifier
-                         view:(UICollectionView *)collectionView {
-  FirebaseArray *array = [[FirebaseArray alloc] initWithQuery:query];
-  self = [super initWithArray:array];
-  if (self) {
-    if (!model) {
-      model = [FIRDataSnapshot class];
-    }
-
-    if (!cell) {
-      cell = [UICollectionViewCell class];
-    }
-
-    self.collectionView = collectionView;
-    self.modelClass = model;
-    self.cellClass = cell;
-    self.reuseIdentifier = identifier;
-    self.populateCell = ^(id cell, id object) {};
-
-    if (!self.hasPrototypeCell) {
-      [self.collectionView registerClass:self.cellClass
-              forCellWithReuseIdentifier:self.reuseIdentifier];
-    }
-  }
-  return self;
-}
-
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-                   modelClass:(Class)model
-                     nibNamed:(NSString *)nibName
-          cellReuseIdentifier:(NSString *)identifier
-                         view:(UICollectionView *)collectionView {
+                         view:(UICollectionView *)collectionView
+                 populateCell:(UICollectionViewCell *(^)(NSIndexPath *,
+                                                         UICollectionView *,
+                                                         FIRDataSnapshot *))populateCell {
   FirebaseArray *array = [[FirebaseArray alloc] initWithQuery:query];
   self = [super initWithArray:array];
   if (self) {
-    if (!model) {
-      model = [FIRDataSnapshot class];
-    }
-
-    self.collectionView = collectionView;
-    self.modelClass = model;
-    self.reuseIdentifier = identifier;
-    self.populateCell = ^(id cell, id object) {};
-
-    UINib *nib = [UINib nibWithNibName:nibName bundle:nil];
-    [self.collectionView registerNib:nib forCellWithReuseIdentifier:self.reuseIdentifier];
+    _collectionView = collectionView;
+    _populateCellAtIndexPath = populateCell;
   }
   return self;
 }
@@ -263,19 +67,9 @@ - (void)array:(FirebaseArray *)array didMoveObject:(id)object
 
 - (nonnull UICollectionViewCell *)collectionView:(nonnull UICollectionView *)collectionView
                           cellForItemAtIndexPath:(nonnull NSIndexPath *)indexPath {
-  id cell = [self.collectionView dequeueReusableCellWithReuseIdentifier:self.reuseIdentifier
-                                                           forIndexPath:indexPath];
-
   FIRDataSnapshot *snap = [self.items objectAtIndex:indexPath.row];
-  if (![self.modelClass isSubclassOfClass:[FIRDataSnapshot class]]) {
-    id model = [[self.modelClass alloc] init];
-    // TODO: replace setValuesForKeysWithDictionary with client API
-    // valueAsObject method
-    [model setValuesForKeysWithDictionary:snap.value];
-    self.populateCell(cell, model);
-  } else {
-    self.populateCell(cell, snap);
-  }
+
+  UICollectionViewCell *cell = self.populateCellAtIndexPath(indexPath, collectionView, snap);
 
   return cell;
 }
@@ -289,27 +83,4 @@ - (NSInteger)collectionView:(nonnull UICollectionView *)collectionView
   return self.count;
 }
 
-- (void)populateCellWithBlock:(void (^)(__kindof UICollectionViewCell *cell,
-                                        __kindof NSObject *object))callback {
-  self.populateCell = callback;
-}
-
-#pragma mark - Accessors
-
-- (void)setModelClass:(Class)modelClass {
-  if (modelClass == nil) {
-    _modelClass = [FIRDataSnapshot class];
-  } else {
-    _modelClass = modelClass;
-  }
-}
-
-- (void)setCellClass:(Class)cellClass {
-  if (cellClass == nil) {
-    _cellClass = [UICollectionViewCell class];
-  } else {
-    _cellClass = cellClass;
-  }
-}
-
 @end

From 3c286b9ad4793d942627ebed7ab685455e4332b6 Mon Sep 17 00:00:00 2001
From: Morgan Chen <morganchen12@gmail.com>
Date: Wed, 19 Oct 2016 17:10:11 -0700
Subject: [PATCH 2/4] change tests for new api

---
 FirebaseDatabaseUI/FirebaseCollectionViewDataSource.h  |  1 -
 .../FirebaseCollectionViewDataSourceTest.m             | 10 +++++-----
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.h b/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.h
index 76eb65c47d0..cef0f5d70a4 100644
--- a/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.h
+++ b/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.h
@@ -65,7 +65,6 @@ NS_ASSUME_NONNULL_BEGIN
  * UICollectionViewCells
  * with FIRDataSnapshots.
  * @param query A Firebase query to bind the datasource to
- * @param identifier A string to use as a CellReuseIdentifier
  * @param collectionView An instance of a UICollectionView to bind to
  * @return An instance of FirebaseCollectionViewDataSource that populates
  * UICollectionViewCells with
diff --git a/FirebaseDatabaseUITests/FirebaseCollectionViewDataSourceTest.m b/FirebaseDatabaseUITests/FirebaseCollectionViewDataSourceTest.m
index 9645b1f1b62..61a578814b9 100644
--- a/FirebaseDatabaseUITests/FirebaseCollectionViewDataSourceTest.m
+++ b/FirebaseDatabaseUITests/FirebaseCollectionViewDataSourceTest.m
@@ -44,12 +44,12 @@ - (void)setUp {
   self.observable = [[FUITestObservable alloc] init];
   // Horrible abuse of type system, knowing that the initializer passes the observable straight to
   // FirebaseArray anyway.
-  self.dataSource = [[FirebaseCollectionViewDataSource alloc] initWithRef:(FIRDatabaseReference *)self.observable
-                                                      cellReuseIdentifier:kTestReuseIdentifier
-                                                                     view:self.collectionView];
-  [self.dataSource populateCellWithBlock:^(__kindof UICollectionViewCell *_Nonnull cell,
-                                           FUIFakeSnapshot * _Nonnull object) {
+  self.dataSource = [[FirebaseCollectionViewDataSource alloc] initWithQuery:(FIRDatabaseReference *)self.observable
+                                                                       view:self.collectionView
+                                                               populateCell:^UICollectionViewCell *(NSIndexPath *indexPath, UICollectionView *collectionView, FIRDataSnapshot *object) {
+    UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:kTestReuseIdentifier forIndexPath:indexPath];
     cell.accessibilityValue = object.key;
+    return cell;
   }];
   self.collectionView.dataSource = self.dataSource;
   

From 752624884a9b7951469d52bc231e56793681b15a Mon Sep 17 00:00:00 2001
From: Morgan Chen <morganchen12@gmail.com>
Date: Thu, 20 Oct 2016 10:58:17 -0700
Subject: [PATCH 3/4] refactor table view data source

---
 .../FirebaseCollectionViewDataSource.h        |  25 +-
 .../FirebaseCollectionViewDataSource.m        |   6 +-
 .../FirebaseTableViewDataSource.h             | 371 ++----------------
 .../FirebaseTableViewDataSource.m             | 241 +-----------
 .../FirebaseCollectionViewDataSourceTest.m    |   2 +-
 .../FirebaseTableViewDataSourceTest.m         |  12 +-
 6 files changed, 65 insertions(+), 592 deletions(-)

diff --git a/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.h b/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.h
index cef0f5d70a4..d3650c5eaf0 100644
--- a/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.h
+++ b/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.h
@@ -58,23 +58,28 @@ NS_ASSUME_NONNULL_BEGIN
  * provided by the datasource.
  */
 @property(strong, nonatomic, readonly) UICollectionViewCell *(^populateCellAtIndexPath)
-  (NSIndexPath *indexPath, UICollectionView *collectionView, FIRDataSnapshot *object);
+  (UICollectionView *collectionView, NSIndexPath *indexPath, FIRDataSnapshot *object);
 
 /**
  * Initialize an instance of FirebaseCollectionViewDataSource that populates
- * UICollectionViewCells
- * with FIRDataSnapshots.
- * @param query A Firebase query to bind the datasource to
- * @param collectionView An instance of a UICollectionView to bind to
+ * UICollectionViewCells with FIRDataSnapshots.
+ * @param query A Firebase query to bind the data source to.
+ * @param collectionView An instance of a UICollectionView to bind to. This view
+ *   is not retained by its data source.
+ * @param populateCell A closure used by the data source to create the cells that 
+ *   are displayed in the collection view. This closure is retained by the data
+ *   source, so if you capture self in the closure and also claim ownership of the
+ *   data source, be sure to avoid retain cycles by capturing a weak reference to self.
  * @return An instance of FirebaseCollectionViewDataSource that populates
- * UICollectionViewCells with
- * FIRDataSnapshots
+ *   UICollectionViewCells with FIRDataSnapshots.
  */
 - (instancetype)initWithQuery:(FIRDatabaseQuery *)query
                          view:(UICollectionView *)collectionView
-                 populateCell:(UICollectionViewCell * (^)(NSIndexPath *indexPath,
-                                                          UICollectionView *collectionView,
-                                                          FIRDataSnapshot *object))populateCell;
+                 populateCell:(UICollectionViewCell *(^)(UICollectionView *collectionView,
+                                                         NSIndexPath *indexPath,
+                                                         FIRDataSnapshot *object))populateCell NS_DESIGNATED_INITIALIZER;
+
+- (instancetype)initWithArray:(FirebaseArray *)array NS_UNAVAILABLE;
 
 @end
 
diff --git a/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.m b/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.m
index 94bbab38fee..a8954832c00 100644
--- a/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.m
+++ b/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.m
@@ -28,8 +28,8 @@ @implementation FirebaseCollectionViewDataSource
 
 - (instancetype)initWithQuery:(FIRDatabaseQuery *)query
                          view:(UICollectionView *)collectionView
-                 populateCell:(UICollectionViewCell *(^)(NSIndexPath *,
-                                                         UICollectionView *,
+                 populateCell:(UICollectionViewCell *(^)(UICollectionView *,
+                                                         NSIndexPath *,
                                                          FIRDataSnapshot *))populateCell {
   FirebaseArray *array = [[FirebaseArray alloc] initWithQuery:query];
   self = [super initWithArray:array];
@@ -69,7 +69,7 @@ - (nonnull UICollectionViewCell *)collectionView:(nonnull UICollectionView *)col
                           cellForItemAtIndexPath:(nonnull NSIndexPath *)indexPath {
   FIRDataSnapshot *snap = [self.items objectAtIndex:indexPath.row];
 
-  UICollectionViewCell *cell = self.populateCellAtIndexPath(indexPath, collectionView, snap);
+  UICollectionViewCell *cell = self.populateCellAtIndexPath(collectionView, indexPath, snap);
 
   return cell;
 }
diff --git a/FirebaseDatabaseUI/FirebaseTableViewDataSource.h b/FirebaseDatabaseUI/FirebaseTableViewDataSource.h
index 6b840c71c81..114d3c747eb 100644
--- a/FirebaseDatabaseUI/FirebaseTableViewDataSource.h
+++ b/FirebaseDatabaseUI/FirebaseTableViewDataSource.h
@@ -18,7 +18,7 @@
 
 // clang-format on
 
-#import <UIKit/UIKit.h>
+@import UIKit;
 
 #import "FirebaseDataSource.h"
 
@@ -28,366 +28,49 @@ NS_ASSUME_NONNULL_BEGIN
 
 /**
  * FirebaseTableViewDataSource provides an class that conforms to the
- * UITableViewDataSource protocol
- * which allows UITableViews to implement FirebaseTableViewDataSource in order
- * to provide a
- * UITableView synchronized to a Firebase reference or query. In addition to
- * handling all Firebase
- * child events (added, changed, removed, moved), FirebaseTableViewDataSource
- * handles
- * UITableViewCell creation, either with the default UITableViewCell, prototype
- * cells, custom
- * UITableViewCell subclasses, or custom XIBs, and provides a simple
- * [FirebaseTableViewDataSource
- * populateCellWithBlock:] method which allows developers to populate the cells
- * created for them
+ * UITableViewDataSource protocol which allows UITableViews to implement 
+ * FirebaseTableViewDataSource in order to provide a UITableView synchronized 
+ * to a Firebase reference or query. In addition to handling all Firebase 
+ * child events (added, changed, removed, moved), FirebaseTableViewDataSource 
+ * handles UITableViewCell creation, either with the default UITableViewCell, 
+ * prototype cells, custom UITableViewCell subclasses, or custom XIBs, and 
+ * provides a simple [FirebaseTableViewDataSource populateCellWithBlock:]
+ * method which allows developers to populate the cells created for them
  * with desired data from Firebase.
  */
 @interface FirebaseTableViewDataSource : FirebaseDataSource<UITableViewDataSource>
 
-/**
- * The model class to coerce FIRDataSnapshots to (if desired). For instance, if
- * the modelClass is set
- * to [Message class] in Obj-C or Message.self in Swift, then objects of type
- * Message will be
- * returned instead of type FIRDataSnapshot.
- * Defaults to FIRDataSnapshot.
- */
-@property(strong, nonatomic, null_resettable) Class modelClass;
-
-/**
- * The reuse identifier for cells in the UITableView.
- */
-@property(strong, nonatomic) NSString *reuseIdentifier;
-
 /**
  * The UITableView instance that operations (inserts, removals, moves, etc.) are
  * performed against.
  */
-@property(strong, nonatomic) UITableView *tableView;
-
-/**
- * Property to keep track of prototype cell use, to not register a class for the
- * UICollectionView or
- * do similar book keeping.
- */
-@property BOOL hasPrototypeCell;
-
-/**
- * The callback to populate a subclass of UITableViewCell with an object
- * provided by the datasource.
- */
-@property(strong, nonatomic, readonly) void (^populateCell)
-  (__kindof UITableViewCell *cell,__kindof NSObject  *object);
-
-/**
- * Initialize an instance of FirebaseTableViewDataSource that populates
- * UITableViewCells with
- * FIRDataSnapshots.
- * @param ref A Firebase reference to bind the datasource to
- * @param identifier A string to use as a CellReuseIdentifier
- * @param tableView An instance of a UITableView to bind to
- * @return An instance of FirebaseTableViewDataSource that populates
- * UITableViewCells with
- * FIRDataSnapshots
- */
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-                   cellReuseIdentifier:(NSString *)identifier
-                                  view:(UITableView *)tableView;
-
-/**
- * Initialize an instance of FirebaseTableViewDataSource that populates
- * UITableViewCells with
- * FIRDataSnapshots. Note that this method is used when using prototype cells,
- * where the cells don't
- * need to be registered in the class.
- * @param ref A Firebase reference to bind the datasource to
- * @param identifier A string to use as a CellReuseIdentifier
- * @param tableView An instance of a UITableView to bind to
- * @return An instance of FirebaseTableViewDataSource that populates
- * UITableViewCells with
- * FIRDataSnapshots
- */
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-              prototypeReuseIdentifier:(NSString *)identifier
-                                  view:(UITableView *)tableView;
-
-/**
- * Initialize an instance of FirebaseTableViewDataSource that populates a custom
- * subclass of
- * UITableViewCell with FIRDataSnapshots.
- * @param ref A Firebase reference to bind the datasource to
- * @param cell A subclass of UITableViewCell used to populate the UITableView,
- * defaults to
- * UITableViewCell if nil
- * @param identifier A string to use as a CellReuseIdentifier
- * @param tableView An instance of a UITableView to bind to
- * @return An instance of FirebaseTableViewDataSource that populates a custom
- * subclass of
- * UITableViewCell with FIRDataSnapshots
- */
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-                             cellClass:(nullable Class)cell
-                   cellReuseIdentifier:(NSString *)identifier
-                                  view:(UITableView *)tableView;
-
-/**
- * Initialize an instance of FirebaseTableViewDataSource that populates a custom
- * xib with
- * FIRDataSnapshots.
- * @param ref A Firebase reference to bind the datasource to
- * @param nibName The name of a xib file to create the layout for a
- * UITableViewCell
- * @param identifier A string to use as a CellReuseIdentifier
- * @param tableView An instance of a UITableView to bind to
- * @return An instance of FirebaseTableViewDataSource that populates a custom
- * xib with
- * FIRDataSnapshots
- */
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-                              nibNamed:(NSString *)nibName
-                   cellReuseIdentifier:(NSString *)identifier
-                                  view:(UITableView *)tableView;
-
-/**
- * Initialize an instance of FirebaseTableViewDataSource that populates
- * UITableViewCells with a
- * custom model class.
- * @param ref A Firebase reference to bind the datasource to
- * @param model A custom class that FIRDataSnapshots are coerced to, defaults to
- * FIRDataSnapshot if nil
- * @param identifier A string to use as a CellReuseIdentifier
- * @param tableView An instance of a UITableView to bind to
- * @return An instance of FirebaseTableViewDataSource that populates
- * UITableViewCells with a custom
- * model class
- */
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-                            modelClass:(nullable Class)model
-                   cellReuseIdentifier:(NSString *)identifier
-                                  view:(UITableView *)tableView;
-
-/**
- * Initialize an instance of FirebaseTableViewDataSource that populates
- * UITableViewCells with a
- * custom model class. Note that this method is used when using prototype cells,
- * where the cells
- * don't need to be registered in the class.
- * @param ref A Firebase reference to bind the datasource to
- * @param model A custom class that FIRDataSnapshots are coerced to, defaults to
- * FIRDataSnapshot if nil
- * @param identifier A string to use as a CellReuseIdentifier
- * @param tableView An instance of a UITableView to bind to
- * @return An instance of FirebaseTableViewDataSource that populates
- * UITableViewCells with a custom
- * model class
- */
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-                            modelClass:(nullable Class)model
-              prototypeReuseIdentifier:(NSString *)identifier
-                                  view:(UITableView *)tableView;
-
-/**
- * Initialize an instance of FirebaseTableViewDataSource that populates a custom
- * subclass of
- * UITableViewCell with a custom model class.
- * @param ref A Firebase reference to bind the datasource to
- * @param model A custom class that FIRDataSnapshots are coerced to, defaults to
- * FIRDataSnapshot if nil
- * @param cell A subclass of UITableViewCell used to populate the UITableView,
- * defaults to
- * UITableViewCell if nil
- * @param identifier A string to use as a CellReuseIdentifier
- * @param tableView An instance of a UITableView to bind to
- * @return An instance of FirebaseTableViewDataSource that populates a custom
- * subclass of
- * UITableViewCell with a custom model class
- */
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-                            modelClass:(nullable Class)model
-                             cellClass:(nullable Class)cell
-                   cellReuseIdentifier:(NSString *)identifier
-                                  view:(UITableView *)tableView;
-
-/**
- * Initialize an instance of FirebaseTableViewDataSource that populates a custom
- * xib with a custom
- * model class.
- * @param ref A Firebase reference to bind the datasource to
- * @param model A custom class that FIRDataSnapshots are coerced to, defaults to
- * FIRDataSnapshot if nil
- * @param nibName The name of a xib file to create the layout for a
- * UITableViewCell
- * @param identifier A string to use as a CellReuseIdentifier
- * @param tableView An instance of a UITableView to bind to
- * @return An instance of FirebaseTableViewDataSource that populates a custom
- * xib with a custom
- * model class
- */
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-                            modelClass:(nullable Class)model
-                              nibNamed:(NSString *)nibName
-                   cellReuseIdentifier:(NSString *)identifier
-                                  view:(UITableView *)tableView;
-
-/**
- * Initialize an instance of FirebaseTableViewDataSource that populates
- * UITableViewCells with
- * FIRDataSnapshots.
- * @param query A Firebase query to bind the datasource to
- * @param identifier A string to use as a CellReuseIdentifier
- * @param tableView An instance of a UITableView to bind to
- * @return An instance of FirebaseTableViewDataSource that populates
- * UITableViewCells with
- * FIRDataSnapshots
- */
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-                     cellReuseIdentifier:(NSString *)identifier
-                                    view:(UITableView *)tableView;
+@property (nonatomic, readonly, weak) UITableView *tableView;
 
 /**
- * Initialize an instance of FirebaseTableViewDataSource that populates
- * UITableViewCells with
- * FIRDataSnapshots. Note that this method is used when using prototype cells,
- * where the cells don't
- * need to be registered in the class.
- * @param query A Firebase query to bind the datasource to
- * @param identifier A string to use as a CellReuseIdentifier
- * @param tableView An instance of a UITableView to bind to
- * @return An instance of FirebaseTableViewDataSource that populates
- * UITableViewCells with
- * FIRDataSnapshots
+ * The callback used by the data source to populate the table view.
  */
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-                prototypeReuseIdentifier:(NSString *)identifier
-                                    view:(UITableView *)tableView;
+@property(strong, nonatomic, readonly) UITableViewCell *(^populateCell)
+  (UITableView *tableView, NSIndexPath *indexPath, FIRDataSnapshot *snap);
 
-/**
- * Initialize an instance of FirebaseTableViewDataSource that populates a custom
- * subclass of
- * UITableViewCell with FIRDataSnapshots.
- * @param query A Firebase query to bind the datasource to
- * @param cell A subclass of UITableViewCell used to populate the UITableView,
- * defaults to
- * UITableViewCell if nil
- * @param identifier A string to use as a CellReuseIdentifier
- * @param tableView An instance of a UITableView to bind to
- * @return An instance of FirebaseTableViewDataSource that populates a custom
- * subclass of
- * UITableViewCell with FIRDataSnapshots
- */
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-                               cellClass:(nullable Class)cell
-                     cellReuseIdentifier:(NSString *)identifier
-                                    view:(UITableView *)tableView;
 
 /**
- * Initialize an instance of FirebaseTableViewDataSource that populates a custom
- * xib with
- * FIRDataSnapshots.
- * @param query A Firebase query to bind the datasource to
- * @param nibName The name of a xib file to create the layout for a
- * UITableViewCell
- * @param identifier A string to use as a CellReuseIdentifier
- * @param tableView An instance of a UITableView to bind to
- * @return An instance of FirebaseTableViewDataSource that populates a custom
- * xib with
- * FIRDataSnapshots
+ * Initialize an instance of FirebaseTableViewDataSource.
+ * @param query A Firebase query to bind the data source to.
+ * @param tableView An instance of a UITableView to bind to. This view is
+ *   not retained by the data source.
+ * @param populateCell A closure used by the data source to create/reuse
+ *   table view cells and populate their content. This closure is retained
+ *   by the data source, so if you capture self in the closure and also claim ownership 
+ *   of the data source, be sure to avoid retain cycles by capturing a weak reference to self.
+ * @return An instance of FirebaseTableViewDataSource.
  */
 - (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-                                nibNamed:(NSString *)nibName
-                     cellReuseIdentifier:(NSString *)identifier
-                                    view:(UITableView *)tableView;
+                         view:(UITableView *)tableView
+                 populateCell:(UITableViewCell *(^)(UITableView *tableView,
+                                                    NSIndexPath *indexPath,
+                                                    FIRDataSnapshot *object))populateCell NS_DESIGNATED_INITIALIZER;
 
-/**
- * Initialize an instance of FirebaseTableViewDataSource that populates
- * UITableViewCells with a
- * custom model class.
- * @param query A Firebase query to bind the datasource to
- * @param model A custom class that FIRDataSnapshots are coerced to, defaults to
- * FIRDataSnapshot if nil
- * @param identifier A string to use as a CellReuseIdentifier
- * @param tableView An instance of a UITableView to bind to
- * @return An instance of FirebaseTableViewDataSource that populates
- * UITableViewCells with a custom
- * model class
- */
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-                              modelClass:(nullable Class)model
-                     cellReuseIdentifier:(NSString *)identifier
-                                    view:(UITableView *)tableView;
-
-/**
- * Initialize an instance of FirebaseTableViewDataSource that populates
- * UITableViewCells with a
- * custom model class. Note that this method is used when using prototype cells,
- * where the cells
- * don't need to be registered in the class.
- * @param query A Firebase query to bind the datasource to
- * @param model A custom class that FIRDataSnapshots are coerced to, defaults to
- * FIRDataSnapshot if nil
- * @param identifier A string to use as a CellReuseIdentifier
- * @param tableView An instance of a UITableView to bind to
- * @return An instance of FirebaseTableViewDataSource that populates
- * UITableViewCells with a custom
- * model class
- */
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-                              modelClass:(nullable Class)model
-                prototypeReuseIdentifier:(NSString *)identifier
-                                    view:(UITableView *)tableView;
-
-/**
- * Initialize an instance of FirebaseTableViewDataSource that populates a custom
- * subclass of
- * UITableViewCell with a custom model class.
- * @param query A Firebase query to bind the datasource to
- * @param model A custom class that FIRDataSnapshots are coerced to, defaults to
- * FIRDataSnapshot if nil
- * @param cell A subclass of UITableViewCell used to populate the UITableView,
- * defaults to
- * UITableViewCell if nil
- * @param identifier A string to use as a CellReuseIdentifier
- * @param tableView An instance of a UITableView to bind to
- * @return An instance of FirebaseTableViewDataSource that populates a custom
- * subclass of
- * UITableViewCell with a custom model class
- */
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-                              modelClass:(nullable Class)model
-                               cellClass:(nullable Class)cell
-                     cellReuseIdentifier:(NSString *)identifier
-                                    view:(UITableView *)tableView;
-
-/**
- * Initialize an instance of FirebaseTableViewDataSource that populates a custom
- * xib with a custom
- * model class.
- * @param query A Firebase query to bind the datasource to
- * @param model A custom class that FIRDataSnapshots are coerced to, defaults to
- * FIRDataSnapshot if nil
- * @param nibName The name of a xib file to create the layout for a
- * UITableViewCell
- * @param identifier A string to use as a CellReuseIdentifier
- * @param tableView An instance of a UITableView to bind to
- * @return An instance of FirebaseTableViewDataSource that populates a custom
- * xib with a custom
- * model class
- */
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-                              modelClass:(nullable Class)model
-                                nibNamed:(NSString *)nibName
-                     cellReuseIdentifier:(NSString *)identifier
-                                    view:(UITableView *)tableView;
-
-/**
- * This method populates the fields of a UITableViewCell or subclass given a
- * model object (or
- * FIRDataSnapshot).
- * @param callback A block which returns an initialized UITableViewCell 
- * (or subclass) and the corresponding object to populate the cell with.
- */
-- (void)populateCellWithBlock:(void (^)(__kindof UITableViewCell *cell, __kindof NSObject *object))callback;
+- (instancetype)initWithArray:(FirebaseArray *)array NS_UNAVAILABLE;
 
 @end
 
diff --git a/FirebaseDatabaseUI/FirebaseTableViewDataSource.m b/FirebaseDatabaseUI/FirebaseTableViewDataSource.m
index 997ebab7403..bd1ae1959cf 100644
--- a/FirebaseDatabaseUI/FirebaseTableViewDataSource.m
+++ b/FirebaseDatabaseUI/FirebaseTableViewDataSource.m
@@ -23,219 +23,28 @@
 @import FirebaseDatabase;
 
 @interface FirebaseTableViewDataSource ()
-@property(strong, nonatomic) void (^populateCell)
-  (__kindof UITableViewCell *cell,__kindof NSObject  *object);
-@end
-
-@implementation FirebaseTableViewDataSource
-
-#pragma mark - FirebaseDataSource initializer methods
-
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-        cellReuseIdentifier:(NSString *)identifier
-                       view:(UITableView *)tableView {
-  return [self initWithQuery:ref
-                  modelClass:nil
-                   cellClass:nil
-         cellReuseIdentifier:identifier
-                        view:tableView];
-}
-
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-   prototypeReuseIdentifier:(NSString *)identifier
-                       view:(UITableView *)tableView {
-  return [self initWithQuery:ref
-                  modelClass:nil
-                   cellClass:nil
-         cellReuseIdentifier:identifier
-                        view:tableView];
-}
-
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-                  cellClass:(Class)cell
-        cellReuseIdentifier:(NSString *)identifier
-                       view:(UITableView *)tableView {
-  return [self initWithQuery:ref
-                  modelClass:nil
-                   cellClass:cell
-         cellReuseIdentifier:identifier
-                        view:tableView];
-}
-
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-                   nibNamed:(NSString *)nibName
-        cellReuseIdentifier:(NSString *)identifier
-                       view:(UITableView *)tableView {
-  return [self initWithQuery:ref
-                  modelClass:nil
-                    nibNamed:nibName
-         cellReuseIdentifier:identifier
-                        view:tableView];
-}
-
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-                 modelClass:(Class)model
-        cellReuseIdentifier:(NSString *)identifier
-                       view:(UITableView *)tableView {
-  return [self initWithQuery:ref
-                  modelClass:model
-                   cellClass:nil
-         cellReuseIdentifier:identifier
-                        view:tableView];
-}
 
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-                 modelClass:(Class)model
-   prototypeReuseIdentifier:(NSString *)identifier
-                       view:(UITableView *)tableView {
-  return [self initWithQuery:ref
-                  modelClass:model
-                   cellClass:nil
-         cellReuseIdentifier:identifier
-                        view:tableView];
-}
-
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-                 modelClass:(Class)model
-                  cellClass:(Class)cell
-        cellReuseIdentifier:(NSString *)identifier
-                       view:(UITableView *)tableView {
-  return [self initWithQuery:ref
-                  modelClass:model
-                   cellClass:cell
-         cellReuseIdentifier:identifier
-                        view:tableView];
-}
-
-- (instancetype)initWithRef:(FIRDatabaseReference *)ref
-                 modelClass:(Class)model
-                   nibNamed:(NSString *)nibName
-        cellReuseIdentifier:(NSString *)identifier
-                       view:(UITableView *)tableView {
-  return [self initWithQuery:ref
-                  modelClass:model
-                    nibNamed:nibName
-         cellReuseIdentifier:identifier
-                        view:tableView];
-}
+@property (nonatomic, readwrite, weak) UITableView *tableView;
 
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-          cellReuseIdentifier:(NSString *)identifier
-                         view:(UITableView *)tableView {
-  return [self initWithQuery:query
-                  modelClass:nil
-                   cellClass:nil
-         cellReuseIdentifier:identifier
-                        view:tableView];
-}
+@property(strong, nonatomic, readwrite) UITableViewCell *(^populateCell)
+  (UITableView *tableView, NSIndexPath *indexPath, FIRDataSnapshot *snap);
 
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-     prototypeReuseIdentifier:(NSString *)identifier
-                         view:(UITableView *)tableView {
-  self.hasPrototypeCell = YES;
-  return [self initWithQuery:query
-                  modelClass:nil
-                   cellClass:nil
-         cellReuseIdentifier:identifier
-                        view:tableView];
-}
-
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-                    cellClass:(Class)cell
-          cellReuseIdentifier:(NSString *)identifier
-                         view:(UITableView *)tableView {
-  return [self initWithQuery:query
-                  modelClass:nil
-                   cellClass:cell
-         cellReuseIdentifier:identifier
-                        view:tableView];
-}
-
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-                     nibNamed:(NSString *)nibName
-          cellReuseIdentifier:(NSString *)identifier
-                         view:(UITableView *)tableView {
-  return [self initWithQuery:query
-                  modelClass:nil
-                    nibNamed:nibName
-         cellReuseIdentifier:identifier
-                        view:tableView];
-}
-
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-                   modelClass:(Class)model
-          cellReuseIdentifier:(NSString *)identifier
-                         view:(UITableView *)tableView {
-  return [self initWithQuery:query
-                  modelClass:model
-                   cellClass:nil
-         cellReuseIdentifier:identifier
-                        view:tableView];
-}
-
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-                   modelClass:(Class)model
-     prototypeReuseIdentifier:(NSString *)identifier
-                         view:(UITableView *)tableView {
-  self.hasPrototypeCell = YES;
-  return [self initWithQuery:query
-                  modelClass:model
-                   cellClass:nil
-         cellReuseIdentifier:identifier
-                        view:tableView];
-}
-
-- (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-                   modelClass:(Class)model
-                    cellClass:(Class)cell
-          cellReuseIdentifier:(NSString *)identifier
-                         view:(UITableView *)tableView {
-  FirebaseArray *array = [[FirebaseArray alloc] initWithQuery:query];
-  self = [super initWithArray:array];
-  if (self) {
-    if (!model) {
-      model = [FIRDataSnapshot class];
-    }
-
-    if (!cell) {
-      cell = [UITableViewCell class];
-    }
+@end
 
-    self.tableView = tableView;
-    self.modelClass = model;
-    self.reuseIdentifier = identifier;
-    self.populateCell = ^(id cell, id object) {
-    };
+@implementation FirebaseTableViewDataSource
 
-    if (!self.hasPrototypeCell) {
-      [self.tableView registerClass:cell forCellReuseIdentifier:self.reuseIdentifier];
-    }
-  }
-  return self;
-}
+#pragma mark - FirebaseDataSource initializer methods
 
 - (instancetype)initWithQuery:(FIRDatabaseQuery *)query
-                   modelClass:(Class)model
-                     nibNamed:(NSString *)nibName
-          cellReuseIdentifier:(NSString *)identifier
-                         view:(UITableView *)tableView {
+                         view:(UITableView *)tableView
+                 populateCell:(UITableViewCell *(^)(UITableView *,
+                                                    NSIndexPath *,
+                                                    FIRDataSnapshot *))populateCell {
   FirebaseArray *array = [[FirebaseArray alloc] initWithQuery:query];
   self = [super initWithArray:array];
   if (self) {
-    if (!model) {
-      model = [FIRDataSnapshot class];
-    }
-
     self.tableView = tableView;
-    self.modelClass = model;
-    self.reuseIdentifier = identifier;
-    self.populateCell = ^(id cell, id object) {
-    };
-
-    if (!self.hasPrototypeCell) {
-      UINib *nib = [UINib nibWithNibName:nibName bundle:nil];
-      [self.tableView registerNib:nib forCellReuseIdentifier:self.reuseIdentifier];
-    }
+    self.populateCell = populateCell;
   }
   return self;
 }
@@ -274,20 +83,9 @@ - (void)array:(FirebaseArray *)array didMoveObject:(id)object
 #pragma mark - UITableViewDataSource methods
 
 - (id)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
-  id cell = [self.tableView dequeueReusableCellWithIdentifier:self.reuseIdentifier
-                                                 forIndexPath:indexPath];
-
   FIRDataSnapshot *snap = [self.items objectAtIndex:indexPath.row];
-  if (![self.modelClass isSubclassOfClass:[FIRDataSnapshot class]]) {
-    id model = [[self.modelClass alloc] init];
-    // TODO: replace setValuesForKeysWithDictionary with client API
-    // valueAsObject method
-    [model setValuesForKeysWithDictionary:snap.value];
-    self.populateCell(cell, model);
-  } else {
-    self.populateCell(cell, snap);
-  }
 
+  UITableViewCell *cell = self.populateCell(tableView, indexPath, snap);
   return cell;
 }
 
@@ -295,19 +93,4 @@ - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger
   return self.count;
 }
 
-- (void)populateCellWithBlock:(void (^)(__kindof UITableViewCell *cell,
-                                        __kindof NSObject *object))callback {
-  self.populateCell = callback;
-}
-
-#pragma mark - Accessors
-
-- (void)setModelClass:(Class)modelClass {
-  if (modelClass == nil) {
-    _modelClass = [FIRDataSnapshot class];
-  } else {
-    _modelClass = modelClass;
-  }
-}
-
 @end
diff --git a/FirebaseDatabaseUITests/FirebaseCollectionViewDataSourceTest.m b/FirebaseDatabaseUITests/FirebaseCollectionViewDataSourceTest.m
index 61a578814b9..44357ac831a 100644
--- a/FirebaseDatabaseUITests/FirebaseCollectionViewDataSourceTest.m
+++ b/FirebaseDatabaseUITests/FirebaseCollectionViewDataSourceTest.m
@@ -46,7 +46,7 @@ - (void)setUp {
   // FirebaseArray anyway.
   self.dataSource = [[FirebaseCollectionViewDataSource alloc] initWithQuery:(FIRDatabaseReference *)self.observable
                                                                        view:self.collectionView
-                                                               populateCell:^UICollectionViewCell *(NSIndexPath *indexPath, UICollectionView *collectionView, FIRDataSnapshot *object) {
+                                                               populateCell:^UICollectionViewCell *(UICollectionView *collectionView, NSIndexPath *indexPath, FIRDataSnapshot *object) {
     UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:kTestReuseIdentifier forIndexPath:indexPath];
     cell.accessibilityValue = object.key;
     return cell;
diff --git a/FirebaseDatabaseUITests/FirebaseTableViewDataSourceTest.m b/FirebaseDatabaseUITests/FirebaseTableViewDataSourceTest.m
index a68e207e9e6..54661b26992 100644
--- a/FirebaseDatabaseUITests/FirebaseTableViewDataSourceTest.m
+++ b/FirebaseDatabaseUITests/FirebaseTableViewDataSourceTest.m
@@ -44,12 +44,14 @@ - (void)setUp {
   self.observable = [[FUITestObservable alloc] init];
   // Horrible abuse of type system, knowing that the initializer passes the observable straight to
   // FirebaseArray anyway.
-  self.dataSource = [[FirebaseTableViewDataSource alloc] initWithRef:(FIRDatabaseReference *)self.observable
-                                                 cellReuseIdentifier:kTestReuseIdentifier
-                                                                view:self.tableView];
-  [self.dataSource populateCellWithBlock:^(__kindof UITableViewCell *_Nonnull cell,
-                                           FUIFakeSnapshot * _Nonnull object) {
+  self.dataSource = [[FirebaseTableViewDataSource alloc] initWithQuery:(FIRDatabaseQuery *)self.observable
+                                                                  view:self.tableView
+                                                          populateCell:^UITableViewCell *(UITableView *tableView,
+                                                                                          NSIndexPath *indexPath,
+                                                                                          FIRDataSnapshot *object) {
+    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:kTestReuseIdentifier];
     cell.accessibilityValue = object.key;
+    return cell;
   }];
   self.tableView.dataSource = self.dataSource;
   

From 466cbfa4cde1ae925c66f6c04fae9f20badc526f Mon Sep 17 00:00:00 2001
From: Morgan Chen <morganchen12@gmail.com>
Date: Mon, 24 Oct 2016 16:40:07 -0700
Subject: [PATCH 4/4] add syntax shorthand for data sources

---
 .../FirebaseCollectionViewDataSource.h        | 20 +++++++++++++++++++
 .../FirebaseCollectionViewDataSource.m        | 14 +++++++++++++
 .../FirebaseTableViewDataSource.h             | 20 +++++++++++++++++++
 .../FirebaseTableViewDataSource.m             | 14 +++++++++++++
 .../FirebaseCollectionViewDataSourceTest.m    |  8 ++++----
 .../FirebaseTableViewDataSourceTest.m         | 12 +++++------
 6 files changed, 77 insertions(+), 11 deletions(-)

diff --git a/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.h b/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.h
index d3650c5eaf0..d1cf036cf5b 100644
--- a/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.h
+++ b/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.h
@@ -83,4 +83,24 @@ NS_ASSUME_NONNULL_BEGIN
 
 @end
 
+@interface UICollectionView (FirebaseCollectionViewDataSource)
+
+/**
+ * Creates a data source, attaches it to the collection view, and returns it.
+ * The returned data source is not retained by the collection view and must be
+ * retained or it will be deallocated while still in use by the collection view.
+ * @param query A Firebase database query to bind the collection view to.
+ * @param populateCell A closure used by the data source to create the cells
+ *   displayed in the collection view. The closure is retained by the returned
+ *   data source.
+ * @return The created data source. This value must be retained while the collection
+ *   view is in use.
+ */
+- (FirebaseCollectionViewDataSource *)bindToQuery:(FIRDatabaseQuery *)query
+                                     populateCell:(UICollectionViewCell *(^)(UICollectionView *collectionView,
+                                                                             NSIndexPath *indexPath,
+                                                                             FIRDataSnapshot *object))populateCell __attribute__((warn_unused_result));
+
+@end
+
 NS_ASSUME_NONNULL_END
diff --git a/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.m b/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.m
index a8954832c00..711464e7ffd 100644
--- a/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.m
+++ b/FirebaseDatabaseUI/FirebaseCollectionViewDataSource.m
@@ -84,3 +84,17 @@ - (NSInteger)collectionView:(nonnull UICollectionView *)collectionView
 }
 
 @end
+
+@implementation UICollectionView (FirebaseCollectionViewDataSource)
+
+- (FirebaseCollectionViewDataSource *)bindToQuery:(FIRDatabaseQuery *)query
+                                     populateCell:(UICollectionViewCell *(^)(UICollectionView *,
+                                                                             NSIndexPath *,
+                                                                             FIRDataSnapshot *))populateCell {
+  FirebaseCollectionViewDataSource *dataSource =
+    [[FirebaseCollectionViewDataSource alloc] initWithQuery:query view:self populateCell:populateCell];
+  self.dataSource = dataSource;
+  return dataSource;
+}
+
+@end
diff --git a/FirebaseDatabaseUI/FirebaseTableViewDataSource.h b/FirebaseDatabaseUI/FirebaseTableViewDataSource.h
index 114d3c747eb..cb1c9cec641 100644
--- a/FirebaseDatabaseUI/FirebaseTableViewDataSource.h
+++ b/FirebaseDatabaseUI/FirebaseTableViewDataSource.h
@@ -74,4 +74,24 @@ NS_ASSUME_NONNULL_BEGIN
 
 @end
 
+@interface UITableView (FirebaseTableViewDataSource)
+
+/**
+ * Creates a data source, attaches it to the table view, and returns it.
+ * The returned data source is not retained by the table view and must be
+ * retained or it will be deallocated while still in use by the table view.
+ * @param query A Firebase database query to bind the table view to.
+ * @param populateCell A closure used by the data source to create the cells
+ *   displayed in the table view. The closure is retained by the returned
+ *   data source.
+ * @return The created data source. This value must be retained while the table
+ *   view is in use.
+ */
+- (FirebaseTableViewDataSource *)bindToQuery:(FIRDatabaseQuery *)query
+                                populateCell:(UITableViewCell *(^)(UITableView *tableView,
+                                                                   NSIndexPath *indexPath,
+                                                                   FIRDataSnapshot *object))populateCell __attribute__((warn_unused_result));
+
+@end
+
 NS_ASSUME_NONNULL_END
diff --git a/FirebaseDatabaseUI/FirebaseTableViewDataSource.m b/FirebaseDatabaseUI/FirebaseTableViewDataSource.m
index bd1ae1959cf..cba8739547f 100644
--- a/FirebaseDatabaseUI/FirebaseTableViewDataSource.m
+++ b/FirebaseDatabaseUI/FirebaseTableViewDataSource.m
@@ -94,3 +94,17 @@ - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger
 }
 
 @end
+
+@implementation UITableView (FirebaseTableViewDataSource)
+
+- (FirebaseTableViewDataSource *)bindToQuery:(FIRDatabaseQuery *)query
+                                populateCell:(UITableViewCell *(^)(UITableView *tableView,
+                                                                   NSIndexPath *indexPath,
+                                                                   FIRDataSnapshot *snap))populateCell {
+  FirebaseTableViewDataSource *dataSource =
+    [[FirebaseTableViewDataSource alloc] initWithQuery:query view:self populateCell:populateCell];
+  self.dataSource = dataSource;
+  return dataSource;
+}
+
+@end
diff --git a/FirebaseDatabaseUITests/FirebaseCollectionViewDataSourceTest.m b/FirebaseDatabaseUITests/FirebaseCollectionViewDataSourceTest.m
index 44357ac831a..7f787e7de2e 100644
--- a/FirebaseDatabaseUITests/FirebaseCollectionViewDataSourceTest.m
+++ b/FirebaseDatabaseUITests/FirebaseCollectionViewDataSourceTest.m
@@ -44,14 +44,14 @@ - (void)setUp {
   self.observable = [[FUITestObservable alloc] init];
   // Horrible abuse of type system, knowing that the initializer passes the observable straight to
   // FirebaseArray anyway.
-  self.dataSource = [[FirebaseCollectionViewDataSource alloc] initWithQuery:(FIRDatabaseReference *)self.observable
-                                                                       view:self.collectionView
-                                                               populateCell:^UICollectionViewCell *(UICollectionView *collectionView, NSIndexPath *indexPath, FIRDataSnapshot *object) {
+  self.dataSource = [self.collectionView bindToQuery:(FIRDatabaseReference *)self.observable
+                                        populateCell:^UICollectionViewCell *(UICollectionView *collectionView,
+                                                                             NSIndexPath *indexPath,
+                                                                             FIRDataSnapshot *object) {
     UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:kTestReuseIdentifier forIndexPath:indexPath];
     cell.accessibilityValue = object.key;
     return cell;
   }];
-  self.collectionView.dataSource = self.dataSource;
   
   // Removing this NSLog causes the tests to crash since `numberOfItemsInSection`
   // actually pulls updates from the data source or something
diff --git a/FirebaseDatabaseUITests/FirebaseTableViewDataSourceTest.m b/FirebaseDatabaseUITests/FirebaseTableViewDataSourceTest.m
index 54661b26992..bc81871da2c 100644
--- a/FirebaseDatabaseUITests/FirebaseTableViewDataSourceTest.m
+++ b/FirebaseDatabaseUITests/FirebaseTableViewDataSourceTest.m
@@ -44,17 +44,15 @@ - (void)setUp {
   self.observable = [[FUITestObservable alloc] init];
   // Horrible abuse of type system, knowing that the initializer passes the observable straight to
   // FirebaseArray anyway.
-  self.dataSource = [[FirebaseTableViewDataSource alloc] initWithQuery:(FIRDatabaseQuery *)self.observable
-                                                                  view:self.tableView
-                                                          populateCell:^UITableViewCell *(UITableView *tableView,
-                                                                                          NSIndexPath *indexPath,
-                                                                                          FIRDataSnapshot *object) {
+  self.dataSource = [self.tableView bindToQuery:(FIRDatabaseReference *)self.observable
+                                   populateCell:^UITableViewCell *(UITableView *tableView,
+                                                                   NSIndexPath *indexPath,
+                                                                   FIRDataSnapshot *object) {
     UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:kTestReuseIdentifier];
     cell.accessibilityValue = object.key;
     return cell;
   }];
-  self.tableView.dataSource = self.dataSource;
-  
+
   [self.observable populateWithCount:10];
 }