AsyncMessagesViewController

A smooth, responsive and flexible messages UI library for iOS apps. Built on top of the awesome Texture (formerly AsyncDisplayKit) framework, it takes full advantage of asynchronous layout and rendering to deliver a "butter smooth" scrolling experience.

Dependencies

• Texture.
• SlackTextViewController

Requirements

• iOS 9 and later.
• Swift 4.
• ARC.

Installation

From CocoaPods:

pod 'AsyncMessagesViewController'  

Without CocoaPods

Copy the Source\ directory to your project and install all dependencies.

How to use

• Example project
  • Run pod install.
  • Open AsyncMessagesViewController.xcworkspace.
  • Enjoy the simple ViewController.swift class.
• Model
  • Your message model object should conform to MessageData protocol.
• View
  • MessageCellNode is your friend. Most of the time you don't want to subclass it.
  • There are 2 basic built-in bubble nodes implemented for you: MessageTextBubbleNode for text based messages and MessageNetworkImageBubbleNode for remote image based messages.
  • Need a custom bubble node? Here you go.
• Controller
  • Your view controller should subclass AsyncMessagesViewController. As you may see, it's a very simple view controller (and should be). Most of the magic is in the data source.
  • What data source, you may ask. Any data source that conform to AsyncMessagesCollectionViewDataSource protocol.
  • There is a default implemention: DefaultAsyncMessagesCollectionViewDataSource. This class keeps a sorted list of messages, but doesn't allow you to change them directly. Instead, you must alter messages using given methods in its protocol and let it handle the heavy work. It can (supposedly) smartly determine which cells need to be inserted, deleted and reloaded. Why? because:
    • Calling reloadData is very expensive on ASCollectionView (and ASTableView).
    • Most of the time, inserting/deleting a cell causing UI changes in other cells as well. DefaultAsyncMessagesCollectionViewDataSource can detect those changes automatically.
  • MessageCellNodeMetadata provides runtime-computed information about a message and how its data should be presented in a MessageCellNode. Metadata of a message is often computed based on the relationship with other messages. For example, message's sender name should be displayed if it is an incoming message and is the first one in a set of consecutive messages sent by a same user. Or message's date should be shown if it is the first message sent within a 15 minutes window. This kind of UI logic is encapsulated in MessageCellNodeMetadataFactory and computed at runtime. Of course you can implement your own logic.

Customizations

• Custom bubble node:
  • Please read this guide on subclassing ASDisplayNode.
  • Implement a factory that conforms to MessageBubbleNodeFactory protocol.
  • Inject your factory to DefaultAsyncMessagesCollectionViewDataSource via its initializer.
  • Inject the data source to AsyncMessagesViewController (also via its initializer).
• Custom bubble image's colors:
  • Initiate a MessageBubbleImageProvider with whatever colors you want.
  • Inject it to your data source.
  • Inject the data source to your view controller.
• Custom bubble images:
  • Implementing your own MessageBubbleImageProvider.
  • Inject it to your data source.
  • Inject the data source to your view controller.
• Custom logic for computing cell metadata:
  • Subclass MessageCellNodeMetadataFactory and override any neccessary method.
  • Inject it to your data source.
  • Inject the data source to your view controller.
• Custom format for message date:
  • Subclass MessageTimestampFormatter and override attributedTimestamp(NSDate).
  • Inject it to your data source.
  • Inject the data source to your view controller.
• Any customization related to the input toolbar:
  • Please take a look at SlackTextViewController itself.
• Other customizations:
  • File an issue and I will be more than happy to help :)

Contributing

All feedbacks, questions and pull requests are very welcome. See here for details.

Credits

Created by Huy Nguyen, an Android developer :)

• Inspried by JSQMessagesViewController and Atlas.

License

AsyncMessagesViewController is released under an MIT License. See here for details.

Copyright © 2015 Huy Nguyen.