diff --git a/README.md b/README.md index e93db98c..330010af 100644 --- a/README.md +++ b/README.md @@ -1,14 +1,616 @@ # Ably Chat SDK for Android -This is the repository for the Android version of the Ably Chat SDK. We aim to build the same functionality that’s available in the [JavaScript SDK](https://github.com/ably/ably-chat-js). +

+ Development status + License + +

+ +Ably Chat is a set of purpose-built APIs for a host of chat features enabling you to create 1:1, 1:Many, Many:1 and Many:Many chat rooms for +any scale. It is designed to meet a wide range of chat use cases, such as livestreams, in-game communication, customer support, or social +interactions in SaaS products. Built on [Ably's](https://ably.com/) core service, it abstracts complex details to enable efficient chat +architectures. > [!IMPORTANT] -> This SDK is currently in the early stages of development and is not ready to be used. +> This SDK is currently under development. If you are interested in being an early adopter and providing feedback then you +> can [sign up to the private beta](https://forms.gle/vB2kXhCXrTQpzHLu5) and are welcome +> to [provide us with feedback](https://forms.gle/mBw9M53NYuCBLFpMA). Coming soon: chat moderation, editing and deleting messages. + +Get started using the [📚 documentation](https://ably.com/docs/products/chat). + +![Ably Chat Header](/images/ably-chat-github-header.png) ## Supported Platforms -- Android 24 and above +This SDK works on Android 7.0+ (API level 24+) and Java 8+. + +## Supported chat features + +This project is under development so we will be incrementally adding new features. At this stage, you'll find APIs for the following chat +features: + +- Chat rooms for 1:1, 1:many, many:1 and many:many participation. +- Sending and receiving chat messages. +- Online status aka presence of chat participants. +- Chat room occupancy, i.e total number of connections and presence members. +- Typing indicators +- Room-level reactions (ephemeral at this stage) + +If there are other features you'd like us to prioritize, please [let us know](https://forms.gle/mBw9M53NYuCBLFpMA). + +## Usage + +You will need the following prerequisites: + +- An Ably account + - You can [sign up](https://ably.com/signup) to the generous free tier. +- An Ably API key + - Use the default or create a new API key in an app within + your [Ably account dashboard](https://ably.com/dashboard). + - Make sure your API key has the + following [capabilities](https://ably.com/docs/auth/capabilities): `publish`, `subscribe`, `presence`, `history` and + `channel-metadata`. + +[//]: # (## Installation) + +[//]: # () +[//]: # (The Ably Chat SDK is available on the Maven Central Repository. To include the dependency in your project, add the following to your `build.gradle` file:) + +[//]: # () +[//]: # (For Groovy:) + +[//]: # () +[//]: # (```groovy) + +[//]: # (implementation 'com.ably.chat:android') + +[//]: # (```) + +[//]: # () +[//]: # (For Kotlin Script (`build.gradle.kts`):) + +[//]: # () +[//]: # (```kotlin) + +[//]: # (implementation("com.ably.chat:android")) + +[//]: # (```) + +[//]: # () +[//]: # (### Dependency on ably-android) + +[//]: # () +[//]: # (Certain functionalities are powered by the [ably-android](https://github.com/ably/ably-java) library. ) + +[//]: # (The `ably-android` library is included as an api dependency within the Chat SDK, so there is no need to manually add it to your project.) + +## Versioning + +The Ably client library follows [Semantic Versioning](http://semver.org/). See https://github.com/ably/ably-chat-kotlin/tags for a list of +tagged releases. + +## Instantiation and authentication + +To instantiate the Chat SDK, create an [Ably client](https://ably.com/docs/getting-started/setup) and pass it into the +Chat constructor: + +```kotlin +import com.ably.chat.ChatClient +import io.ably.lib.realtime.AblyRealtime +import io.ably.lib.types.ClientOptions + +val realtimeClient = AblyRealtime( + ClientOptions().apply { + key = "" + clientId = "" + }, +) + +val chatClient = ChatClient(realtimeClient) +``` + +You can use [basic authentication](https://ably.com/docs/auth/basic) i.e. the API Key directly for testing purposes, +however it is strongly recommended that you use [token authentication](https://ably.com/docs/auth/token) in production +environments. + +To use Chat you must also set a [`clientId`](https://ably.com/docs/auth/identified-clients) so that clients are +identifiable. If you are prototyping, you can use `java.util.UUID` to generate an ID. + +## Connections + +The Chat SDK uses a single connection to Ably, which is exposed via the `ChatClient#connection` property. You can use this +property to observe the connection state and take action accordingly. + +### Current connection status + +You can view the current connection status at any time: + +```kotlin +val connectionStatus = chat.connection.status +val connectionError = chat.connection.error +``` + +### Subscribing to connection status changes + +You can subscribe to connection status changes by registering a listener, like so: + +```kotlin +val subscription = chat.connection.onStatusChange { statusChange: ConnectionStatusChange -> + println(statusChange.toString()) +} +``` + +To stop listening to changes, `unsubscribe` method on returned subscription instance: + +```ts +subscription.unsubscribe() +``` + +## Chat rooms + +### Creating or retrieving a chat room + +You can create or retrieve a chat room with name `"basketball-stream"` this way: + +```kotlin +val room = chat.rooms.get("basketball-stream", RoomOptions(reactions = RoomReactionsOptions())) +``` + +The second argument to `rooms.get` is a `RoomOptions` argument, which tells the Chat SDK what features you would like your room to use and +how they should be configured. + +For example, you can set the timeout between keystrokes for typing events as part of the room options. Sensible defaults for each of the +features are provided for your convenience: + +- A typing timeout (time of inactivity before typing stops) of 5 seconds. +- Entry into, and subscription to, presence. + +The defaults options for each feature may be +viewed [here](https://github.com/ably/ably-chat-js/blob/main/chat-android/src/main/java/com/ably/chat/RoomOptions.kt). + +In order to use the same room but with different options, you must first `release` the room before requesting an instance with the changed +options (see below for more information on releasing rooms). + +Note that: + +- If a `release` call is currently in progress for the room (see below), then a call to `get` will wait for that to resolve before resolving + itself. +- If a `get` call is currently in progress for the room and `release` is called, the `get` call will reject. + +### Attaching to a room + +To start receiving events on a room, it must first be attached. This can be done using the `attach` method. + +```kotlin +// Add a listener so it's ready at attach time (see below for more information on listeners) +room.messages.subscribe { message: Message -> + println(message.toString()) +} + +room.attach() +``` + +### Detaching from a room + +To stop receiving events on a room, it must be detached, which can be achieved by using the `detach` method. + +```kotlin +room.detach() +``` + +Note: This does not remove any event listeners you have registered and they will begin to receive events again in the +event that the room is re-attached. + +### Releasing a room + +Depending on your application, you may have multiple rooms that come and go over time (e.g. if you are running 1:1 support chat). When you +are completely finished with a room, you may `release` it which allows the underlying resources to be collected. + +```kotlin +rooms.release("basketball-stream") +``` + +Once `release` is called, the room will become unusable and you will need to get a new instance using `rooms.get` should you wish to +re-start the room. + +Note that releasing a room may be optional for many applications. + +### Monitoring room status + +Monitoring the status of the room is key to a number of common chat features. For example, you might want to display a warning when the room +has become detached. + +### Current status of a room + +To get the current status, you can use the `status` property: + +```kotlin +val roomStatus = room.status +val roomError = room.error +``` + +### Listening to room status updates + +You can also subscribe to changes in the room status and be notified whenever they happen by registering a listener: + +```kotlin +val subscription = room.onStatusChange { statusChange: RoomStatusChange -> + println(statusChange.toString()) +} +``` + +To stop listening to changes, `unsubscribe` method on returned subscription instance: + +```kotlin +subscription.unsubscribe() +``` + +## Handling discontinuity + +There may be instances where the connection to Ably is lost for a period of time, for example, when the user enters a tunnel. In many +circumstances, the connection will recover and operation +will continue with no discontinuity of messages. However, during extended periods of disconnection, continuity cannot be guaranteed and +you'll need to take steps to recover +messages you might have missed. + +Each feature of the Chat SDK provides an `onDiscontinuity` handler. Here you can register a listener that will be notified whenever a +discontinuity in that feature has been observed. + +Taking messages as an example, you can listen for discontinuities like so: + +```kotlin +val subscription = room.messages.onDiscontinuity { reason: ErrorInfo? -> + // Recover from the discontinuity +} +``` + +To stop listening to discontinuities, `unsubscribe` method on returned subscription instance. + +## Chat messages + +### Sending messages + +To send a message, simply call `send` on the `room.messages` property, with the message you want to send. + +```kotlin +val message = room.messages.send(SendMessageParams(text = "text")) +``` + +### Unsubscribing from incoming messages + +When you're done with the listener, call `unsubscribe` to remove that listeners subscription and prevent it from receiving +any more events. + +```kotlin +val subscription = room.messages.subscribe { message: Message -> + println(message.toString()) +} +// Time passes... +subscription.unsubscribe() +``` + +### Retrieving message history + +The messages object also exposes the `get` method which can be used to request historical messages in the chat room according +to the given criteria. It returns a paginated response that can be used to request more messages. + +```kotlin +var historicalMessages = room.messages.get(QueryParams(orderBy = NewestFirst, limit = 50)) +println(historicalMessages.items.toString()) + +while (historicalMessages.hasNext()) { + historicalMessages = historicalMessages.next() + println(historicalMessages.items.toString()) +} + +println("End of messages") +``` + +### Retrieving message history for a subscribed listener + +In addition to being able to unsubscribe from messages, the return value from `messages.subscribe` also includes the `getPreviousMessages` +method. It can be used to request +historical messages in the chat room that were sent up to the point a that particular listener was subscribed. It returns a +paginated response that can be used to request for more messages. + +```kotlin +val subscription = room.messages.subscribe { + println("New message received") +} + +var historicalMessages = subscription.getPreviousMessages(limit = 50) +println(historicalMessages.items.toString()) + +while (historicalMessages.hasNext()) { + historicalMessages = historicalMessages.next() + println(historicalMessages.items.toString()) +} + +println("End of messages") +``` + +## Online status + +### Retrieving online members + +You can get the complete list of currently online or present members, their state and data, by calling the `presence#get` method. + +```kotlin +// Retrieve the entire list of present members +val presentMembers = room.presence.get() + +// You can supply a clientId to retrieve the presence of a specific member with the given clientId +val presentMember = room.presence.get(clientId = "client-id") + +// You can call this to get a simple boolean value of whether a member is present or not +val isPresent = room.presence.isUserPresent("client-id") +``` + +Calls to `presence#get()` will return a list of the presence messages, where each message contains the most recent +data for a member. + +### Entering the presence set + +To appear online for other users, you can enter the presence set of a chat room. While entering presence, you can provide optional data that +will be associated with the presence message. + +```kotlin +room.presence.enter( + JsonObject().apply { + addProperty("status", "online") + }, +) +``` + +### Updating the presence data + +Updates allow you to make changes to the custom data associated with a present user. Common use-cases include updating the users' +status or profile picture. + +```kotlin +room.presence.update( + JsonObject().apply { + addProperty("status", "busy") + }, +) +``` + +### Leaving the presence set + +Ably automatically triggers a presence leave if a client goes offline. But you can also manually leave the presence set as a result of a UI +action. While leaving presence, you can provide optional data that will be associated with the presence message. + +```kotlin +room.presence.leave( + JsonObject().apply { + addProperty("status", "Be back later!") + }, +) +``` + +### Subscribing to presence updates + +You can provide a single listener, if so, the listener will be subscribed to receive all presence event types. + +```kotlin +val subscription = room.presence.subscribe { event: PresenceEvent -> + when (event.action) { + Action.enter -> println("${event.clientId} entered with data: ${event.data}") + Action.leave -> println("${event.clientId} left") + Action.update -> println("${event.clientId} updated with data: ${event.data}") + } +} +``` + +### Unsubscribing from presence updates + +To unsubscribe a specific listener from presence events, you can call the `unsubscribe` method provided in the subscription object returned +by the `subscribe` call. + +```kotlin +val subscription = room.presence.subscribe { event: PresenceEvent -> + // Handle events +} + +// Unsubscribe +subscription.unsubscribe() +``` + +## Typing indicators + +Typing events allow you to inform others that a client is typing and also subscribe to others' typing status. + +### Retrieving the set of current typers + +You can get the complete set of the current typing `clientId`s, by calling the `typing.get` method. + +```kotlin +// Retrieve the entire list of currently typing clients +val currentlyTypingClientIds = room.typing.get() +``` + +### Start typing + +To inform other users that you are typing, you can call the start method. This will begin a timer that will automatically stop typing after +a set amount of time. + +```kotlin +room.typing.start() +``` + +Repeated calls to start will reset the timer, so the clients typing status will remain active. + +```kotlin +room.typing.start() +// Some short delay - still typing +room.typing.start() +// Some short delay - still typing +room.typing.start() +// Some long delay - timer expires, stopped typing event emitted and listeners are notified +``` + +### Stop typing + +You can immediately stop typing without waiting for the timer to expire. + +```kotlin +room.typing.start() +// Some short delay - timer not yet expired +room.typing.stop() +// Timer cleared and stopped typing event emitted and listeners are notified +``` + +### Subscribing to typing updates + +To subscribe to typing events, provide a listener to the `subscribe` method. + +```kotlin +val subscription = room.typing.subscribe { event: TypingEvent -> + println("currently typing: ${event.currentlyTyping}") +} +``` + +### Unsubscribing from typing updates + +To unsubscribe the listener, you can call the `unsubscribe` method on the subscription object returned by the `subscribe` call: + +```kotlin +val subscription = room.typing.subscribe { event: TypingEvent -> + println("currently typing: ${event.currentlyTyping}") +} + +// Time passes +subscription.unsubscribe() +``` + +## Occupancy of a chat room + +Occupancy tells you how many users are connected to the chat room. + +### Subscribing to occupancy updates + +To subscribe to occupancy updates, subscribe a listener to the chat rooms `occupancy` member: + +```kotlin +val subscription = room.occupancy.subscribe { event: OccupancyEvent -> + println(event.toString()) +} +``` + +### Unsubscribing from occupancy updates + +To unsubscribe the listener, you can call the `unsubscribe` method on the subscription object returned by the `subscribe` call: + +```kotlin +val subscription = room.occupancy.subscribe { event: OccupancyEvent -> + println(event.toString()) +} + +// Time passes... +subscription.unsubscribe() +``` + +Occupancy updates are delivered in near-real-time, with updates in quick succession batched together for performance. + +### Retrieving the occupancy of a chat room + +You can request the current occupancy of a chat room using the `occupancy.get` method: + +```kotlin +val occupancy = room.occupancy.get() +``` + +## Room-level reactions + +You can subscribe to and send ephemeral room-level reactions by using the `room.reactions` objects. + +To send room-level reactions, you must be [attached](#attaching-to-a-room) to the room. + +### Sending a reaction + +To send a reaction such as `"like"`: + +```kotlin +room.reactions.send(SendReactionParams(type = "like")) +``` + +You can also add any metadata and headers to reactions: + +```kotlin +room.reactions.send(SendReactionParams( + type ="like", + metadata = mapOf("effect" to "fireworks"), + headers = mapOf("streamId" to "basketball-stream"), +)) +``` + +### Subscribing to room reactions + +Subscribe to receive room-level reactions: + +```kotlin +val subscription = room.reactions.subscribe { reaction: ReactionEvent -> + println("received a ${reaction.type} with metadata ${reaction.metadata}") +} +``` + +### Unsubscribing from room reactions + +To unsubscribe the listener, you can call the `unsubscribe` method on the subscription object returned by the `subscribe` call: + +```kotlin +val subscription = room.reactions.subscribe { reaction: ReactionEvent -> + println("received a ${reaction.type} with metadata ${reaction.metadata}") +} + +// Time passes... +subscription.unsubscribe() +``` + +## In-depth + +### Channels Behind Chat Features + +It might be useful to know that each feature is backed by an underlying Pub/Sub channel. You can use this information to enable +interoperability with other platforms by subscribing to the channels directly using +the [Ably Pub/Sub SDKs](https://ably.com/docs/products/channels) for those platforms. + +The channel for each feature can be obtained via the `channel` property +on that feature. + +```kotlin +val messagesChannel = room.messages.channel +``` + +**Warning**: You should not attempt to change the state of a channel directly. Doing so may cause unintended side-effects in the Chat SDK. + +### Channels Used + +For a given chat room, the channels used for features are as follows: + +| Feature | Channel | +|-----------|--------------------------------------| +| Messages | `::$chat::$chatMessages` | +| Presence | `::$chat::$chatMessages` | +| Occupancy | `::$chat::$chatMessages` | +| Reactions | `::$chat::$reactions` | +| Typing | `::$chat::$typingIndicators` | + +--- ## Contributing -For information on how to contribute to this repository, please see the [contributing guidelines](CONTRIBUTING.md). \ No newline at end of file +For guidance on how to contribute to this project, see the [contributing guidelines](CONTRIBUTING.md). + +## Support, feedback and troubleshooting + +Please visit http://support.ably.com/ for access to our knowledge base and to ask for any assistance. You can also view +the [community reported Github issues](https://github.com/ably/ably-chat-kotlin/issues) or raise one yourself. + +To see what has changed in recent versions, see the [changelog](CHANGELOG.md). + +## Further reading + +- See a [simple chat example](/demo/) in this repo. +- [Sign up](https://forms.gle/gRZa51erqNp1mSxVA) to the private beta and get started. +- [Share feedback or request](https://forms.gle/mBw9M53NYuCBLFpMA) a new feature.