Remove the limitation of 1 cell to 1 section (MessageKit#601)

SD10 · zhongwuzw · commit 07c0e5859759 · 2018-03-29T13:16:32.000+08:00
* Add numberOfSections delegate method

* Remove numberOfMessages(in) and add other two substitution methods

* Fix tests failure
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -8,6 +8,9 @@ The changelog for `MessageKit`. Also see the [releases](https://github.com/Messa
 
 ### Added
 
+- **Breaking Change** Added new `MessagesDataSource` delegate methods, `numberOfSections(in)` and `numberOfItems(inSection:in)`.
+[#601](https://github.com/MessageKit/MessageKit/pull/601) by [@SD10](https://github.com/sd10), [@zhongwuzw](https://github.com/zhongwuzw).
+
 - **Breaking Change** Added new protocol `MediaItem` as the associated value for the
 `MessageData.video` and `MessageData.photo` cases.
 [#587](https://github.com/MessageKit/MessageKit/pull/587) by [@SD10](https://github.com/sd10).
@@ -71,6 +74,9 @@ You must now set this font explicitly through the `emojiMessageSizeCalculator` o
 
 ### Removed
 
+- **Breaking Change** Removed `numberOfMessages(in)` method of `MessagesDataSource`, instead please use `numberOfSections(in)` and `numberOfItems(inSection:in)`.
+[#601](https://github.com/MessageKit/MessageKit/pull/601) by [@SD10](https://github.com/sd10), [@zhongwuzw](https://github.com/zhongwuzw).
+
 - **Breaking Change** Removed the `messageLabelFont` property from `MessagesCollectionViewFlowLayout`.
 You can now set this property through `textMessageSizeCalculator` property.
 [#579](https://github.com/MessageKit/MessageKit/pull/579) by [@SD10](https://github.com/sd10).
diff --git a/Example/Sources/ConversationViewController.swift b/Example/Sources/ConversationViewController.swift
@@ -260,8 +260,8 @@ extension ConversationViewController: MessagesDataSource {
     func currentSender() -> Sender {
         return SampleData.shared.currentSender
     }
-
-    func numberOfMessages(in messagesCollectionView: MessagesCollectionView) -> Int {
+    
+    func numberOfSections(in messagesCollectionView: MessagesCollectionView) -> Int {
         return messageList.count
     }
 
diff --git a/Sources/Controllers/MessagesViewController.swift b/Sources/Controllers/MessagesViewController.swift
@@ -160,17 +160,14 @@ UICollectionViewDelegateFlowLayout, UICollectionViewDataSource {
         guard let collectionView = collectionView as? MessagesCollectionView else {
             fatalError(MessageKitError.notMessagesCollectionView)
         }
-        // Each message is its own section
-        return collectionView.messagesDataSource?.numberOfMessages(in: collectionView) ?? 0
+        return collectionView.messagesDataSource?.numberOfSections(in: collectionView) ?? 0
     }
 
     open func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
         guard let collectionView = collectionView as? MessagesCollectionView else {
             fatalError(MessageKitError.notMessagesCollectionView)
         }
-        let messageCount = collectionView.messagesDataSource?.numberOfMessages(in: collectionView) ?? 0
-        // There will only ever be 1 message per section
-        return messageCount > 0 ? 1 : 0
+        return collectionView.messagesDataSource?.numberOfItems(inSection: section, in: collectionView) ?? 0
     }
 
     open func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
diff --git a/Sources/Protocols/MessagesDataSource.swift b/Sources/Protocols/MessagesDataSource.swift
@@ -45,11 +45,20 @@ public protocol MessagesDataSource: AnyObject {
     ///   - messagesCollectionView: The `MessagesCollectionView` in which the message will be displayed.
     func messageForItem(at indexPath: IndexPath, in messagesCollectionView: MessagesCollectionView) -> MessageType
 
-    /// The number of messages to be displayed in the `MessagesCollectionView`.
+    /// The number of sections to be displayed in the `MessagesCollectionView`.
     ///
     /// - Parameters:
     ///   - messagesCollectionView: The `MessagesCollectionView` in which the messages will be displayed.
-    func numberOfMessages(in messagesCollectionView: MessagesCollectionView) -> Int
+    func numberOfSections(in messagesCollectionView: MessagesCollectionView) -> Int
+
+    /// The number of cells to be displayed in the `MessagesCollectionView`.
+    ///
+    /// - Parameters:
+    ///   - section: The number of the section in which the cells will be displayed.
+    ///   - messagesCollectionView: The `MessagesCollectionView` in which the messages will be displayed.
+    /// - Note:
+    ///   The default implementation of this method returns 1. Putting each message in its own section.
+    func numberOfItems(inSection section: Int, in messagesCollectionView: MessagesCollectionView) -> Int
 
     /// The attributed text to be used for cell's top label.
     ///
@@ -79,6 +88,10 @@ public extension MessagesDataSource {
         return message.sender == currentSender()
     }
 
+    func numberOfItems(inSection section: Int, in messagesCollectionView: MessagesCollectionView) -> Int {
+        return 1
+    }
+
     func cellTopLabelAttributedText(for message: MessageType, at indexPath: IndexPath) -> NSAttributedString? {
         return nil
     }
diff --git a/Tests/ControllersTest/MessagesViewControllerTests.swift b/Tests/ControllersTest/MessagesViewControllerTests.swift
@@ -87,7 +87,7 @@ class MessagesViewControllerTests: XCTestCase {
         sut.messagesCollectionView.reloadData()
 
         let count = sut.messagesCollectionView.numberOfSections
-        let expectedCount = messagesDataSource.numberOfMessages(in: sut.messagesCollectionView)
+        let expectedCount = messagesDataSource.numberOfSections(in: sut.messagesCollectionView)
 
         XCTAssertEqual(count, expectedCount)
     }
diff --git a/Tests/Mocks/MockMessagesDataSource.swift b/Tests/Mocks/MockMessagesDataSource.swift
@@ -35,7 +35,7 @@ class MockMessagesDataSource: MessagesDataSource {
         return senders[0]
     }
 
-    func numberOfMessages(in messagesCollectionView: MessagesCollectionView) -> Int {
+    func numberOfSections(in messagesCollectionView: MessagesCollectionView) -> Int {
         return messages.count
     }
 

Original file line number	Diff line number	Diff line change
`@@ -260,8 +260,8 @@ extension ConversationViewController: MessagesDataSource {`
`260`	`260`	`func currentSender() -> Sender {`
`261`	`261`	`return SampleData.shared.currentSender`
`262`	`262`	`}`
`263`		`-`
`264`		`- func numberOfMessages(in messagesCollectionView: MessagesCollectionView) -> Int {`
	`263`	`+`
	`264`	`+ func numberOfSections(in messagesCollectionView: MessagesCollectionView) -> Int {`
`265`	`265`	`return messageList.count`
`266`	`266`	`}`
`267`	`267`
Original file line number	Diff line number	Diff line change
`@@ -160,17 +160,14 @@ UICollectionViewDelegateFlowLayout, UICollectionViewDataSource {`
`160`	`160`	`guard let collectionView = collectionView as? MessagesCollectionView else {`
`161`	`161`	`fatalError(MessageKitError.notMessagesCollectionView)`
`162`	`162`	`}`
`163`		`- // Each message is its own section`
`164`		`- return collectionView.messagesDataSource?.numberOfMessages(in: collectionView) ?? 0`
	`163`	`+ return collectionView.messagesDataSource?.numberOfSections(in: collectionView) ?? 0`
`165`	`164`	`}`
`166`	`165`
`167`	`166`	`open func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {`
`168`	`167`	`guard let collectionView = collectionView as? MessagesCollectionView else {`
`169`	`168`	`fatalError(MessageKitError.notMessagesCollectionView)`
`170`	`169`	`}`
`171`		`- let messageCount = collectionView.messagesDataSource?.numberOfMessages(in: collectionView) ?? 0`
`172`		`- // There will only ever be 1 message per section`
`173`		`- return messageCount > 0 ? 1 : 0`
	`170`	`+ return collectionView.messagesDataSource?.numberOfItems(inSection: section, in: collectionView) ?? 0`
`174`	`171`	`}`
`175`	`172`
`176`	`173`	`open func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {`
Original file line number	Diff line number	Diff line change
`@@ -87,7 +87,7 @@ class MessagesViewControllerTests: XCTestCase {`
`87`	`87`	`sut.messagesCollectionView.reloadData()`
`88`	`88`
`89`	`89`	`let count = sut.messagesCollectionView.numberOfSections`
`90`		`- let expectedCount = messagesDataSource.numberOfMessages(in: sut.messagesCollectionView)`
	`90`	`+ let expectedCount = messagesDataSource.numberOfSections(in: sut.messagesCollectionView)`
`91`	`91`
`92`	`92`	`XCTAssertEqual(count, expectedCount)`
`93`	`93`	`}`
Original file line number	Diff line number	Diff line change
`@@ -35,7 +35,7 @@ class MockMessagesDataSource: MessagesDataSource {`
`35`	`35`	`return senders[0]`
`36`	`36`	`}`
`37`	`37`
`38`		`- func numberOfMessages(in messagesCollectionView: MessagesCollectionView) -> Int {`
	`38`	`+ func numberOfSections(in messagesCollectionView: MessagesCollectionView) -> Int {`
`39`	`39`	`return messages.count`
`40`	`40`	`}`
`41`	`41`