Ably iOS client library

An iOS client library for ably.io, the realtime messaging service, written in Objective-C.

Documentation

Visit https://www.ably.io/documentation for a complete API reference and more examples.

Installation

You can install Ably for iOS through CocoaPods, Carthage or manually.

Installing through CocoaPods (recommended)

Add this line to your application's Podfile:

# For Xcode 7.3 and newer
pod 'Ably', '~> 1.0'

And then install the dependency:

$ pod install

Installing through Carthage

Add this line to your application's Cartfile:

# For Xcode 7.3 and newer
github "ably/ably-ios" ~> 1.0

And then run carthage update to build the framework and drag the built Ably.framework into your Xcode project.

Manual installation

1. Get the code from GitHub from the release page, or clone it to get the latest, unstable and possibly underdocumented version: git clone git@github.com:ably/ably-ios.git
2. Drag the directory ably-ios/ably-ios into your project as a group.
3. Ably depends on SocketRocket 0.5.1; get it from the releases page and follow its manual installation instructions.
4. Ably also depends on msgpack 0.1.8; get it from the releases page and link it into your project.

Using the Realtime API

Introduction

All examples assume a client has been created as follows:

Swift

// basic auth with an API key
let client = ARTRealtime(key: "xxxx:xxxx")

// using token auth
let client = ARTRealtime(token: "xxxx")

Objective-C

// basic auth with an API key
ARTRealtime* client = [[ARTRealtime alloc] initWithKey:@"xxxx:xxxx"];

// using token auth
ARTRealtime* client = [[ARTRealtime alloc] initWithToken:@"xxxx"];

Connection

Instantiating ARTRealtime starts a connection by default. You can catch connection success or error by listening to the connection's state changes:

Swift

client.connection.on { stateChange in
    let stateChange = stateChange!
    switch stateChange.current {
    case .Connected:
        print("connected!")
    case .Failed:
        print("failed! \(stateChange.reason)")
    default:
        break
    }
}

Objective-C

[client.connection on:^(ARTConnectionStateChange *stateChange) {
    switch (stateChange.current) {
        case ARTRealtimeConnected:
            NSLog(@"connected!");
            break;
        case ARTRealtimeFailed:
            NSLog(@"failed! %@", stateChange.reason);
            break;
        default:
            break;
    }
}];

You can also connect manually by setting the appropiate option.

Swift

let options = ARTClientOptions(key: "xxxx:xxxx")
options.autoConnect = false
let client = ARTRealtime(options: options)
client.connection.connect()

Objective-C

ARTClientOptions *options = [[ARTClientOptions alloc] initWithKey:@"xxxx:xxxx"];
options.autoConnect = false;
ARTRealtime *client = [[ARTRealtime alloc] initWithOptions:options];
[client.connection connect];

Subscribing to a channel

Given:

Swift

let channel = client.channels.get("test")

Objective-C

ARTRealtimeChannel *channel = [client.channels get:@"test"];

Subscribe to all events:

Swift

channel.subscribe { message in
    print(message.name)
    print(message.data)
}

Objective-C

[channel subscribe:^(ARTMessage *message) {
    NSLog(@"%@", message.name);
    NSLog(@"%@", message.data);
}];

Only certain events:

Swift

channel.subscribe("myEvent") { message in
    print(message.name)
    print(message.data)
}

Objective-C

[channel subscribe:@"myEvent" callback:^(ARTMessage *message) {
    NSLog(@"%@", message.name);
    NSLog(@"%@", message.data);
}];

Publishing to a channel

Swift

channel.publish("greeting", data: "Hello World!")

Objective-C

[channel publish:@"greeting" data:@"Hello World!"];

Querying the history

Swift

channel.history { messagesPage, error in
    let messagesPage = messagesPage!
    print(messagesPage.items)
    print(messagesPage.items.first)
    print((messagesPage.items.first as? ARTMessage)?.data) // payload for the message
    print(messagesPage.items.count) // number of messages in the current page of history
    messagesPage.next { nextPage, error in
        // retrieved the next page in nextPage
    }
    print(messagesPage.hasNext) // true, there are more pages
}

Objective-C

[channel history:^(ARTPaginatedResult<ARTMessage *> *messagesPage, ARTErrorInfo *error) {
    NSLog(@"%@", messagesPage.items);
    NSLog(@"%@", messagesPage.items.firstObject);
    NSLog(@"%@", messagesPage.items.firstObject.data); // payload for the message
    NSLog(@"%lu", (unsigned long)[messagesPage.items count]); // number of messages in the current page of history
    [messagesPage next:^(ARTPaginatedResult<ARTMessage *> *nextPage, ARTErrorInfo *error) {
        // retrieved the next page in nextPage
    }];
    NSLog(@"%d", messagesPage.hasNext); // true, there are more pages
}];

Presence on a channel

Swift

let channel = client.channels.get("test")

channel.presence.enter("john.doe") { errorInfo in
    channel.presence.get { members, errorInfo in
        // members is the array of members present
    }
}

Objective-C

[channel.presence enter:@"john.doe" callback:^(ARTErrorInfo *errorInfo) {
    [channel.presence get:^(ARTPaginatedResult<ARTPresenceMessage *> *result, ARTErrorInfo *error) {
        // members is the array of members present
    }];
}];

Querying the presence history

Swift

channel.presence.history { presencePage, error in
    let presencePage = presencePage!
    if let first = presencePage.items.first as? ARTPresenceMessage {
        print(first.action) // Any of .Enter, .Update or .Leave
        print(first.clientId) // client ID of member
        print(first.data) // optional data payload of member
        presencePage.next { nextPage, error in
            // retrieved the next page in nextPage
        }
    }
}

Objective-C

[channel.presence history:^(ARTPaginatedResult<ARTPresenceMessage *> *presencePage, ARTErrorInfo *error) {
    ARTPresenceMessage *first = (ARTPresenceMessage *)presencePage.items.firstObject;
    NSLog(@"%lu", (unsigned long)first.action); // Any of ARTPresenceEnter, ARTPresenceUpdate or ARTPresenceLeave
    NSLog(@"%@", first.clientId); // client ID of member
    NSLog(@"%@", first.data); // optional data payload of member
    [presencePage next:^(ARTPaginatedResult<ARTPresenceMessage *> *nextPage, ARTErrorInfo *error) {
        // retrieved the next page in nextPage
    }];
}];

Using the authCallback

A callback to call to obtain a signed token request.
ARTClientOptions and ARTRealtime objects can be instantiated as follow:

Swift

let clientOptions = ARTClientOptions()
clientOptions.authCallback = { params, callback in
    getTokenRequestJSONFromYourServer(params) { json, error in
        //handle error
        do {
            callback(try ARTTokenRequest.fromJson(json), nil)
        } catch let error as NSError {
            callback(nil, error)
        }
    }
}

let client = ARTRealtime(options:clientOptions)

Objective-C

ARTClientOptions *clientOptions = [[ARTClientOptions alloc] init];
clientOptions.authCallback = ^(ARTTokenParams *params, void(^callback)(id<ARTTokenDetailsCompatible>, NSError*)) {
    [self getTokenRequestJSONFromYourServer:params completion:^(NSDictionary *json, NSError *error) {
        //handle error
        ARTTokenRequest *tokenRequest = [ARTTokenRequest fromJson:json error:&error];
        callback(tokenRequest, error);
    }];
};

ARTRealtime *client = [[ARTRealtime alloc] initWithOptions:clientOptions];

Using the REST API

### Introduction

All examples assume a client and/or channel has been created as follows:

Swift

let client = ARTRest(key: "xxxx:xxxx")
let channel = client.channels.get("test")

Objective-C

ARTRest *client = [[ARTRest alloc] initWithKey:@"xxxx:xxxx"];
ARTRestChannel *channel = [client.channels get:@"test"];

Publishing a message to a channel

Swift

channel.publish("myEvent", data: "Hello!")

Objective-C

[channel publish:@"myEvent" data:@"Hello!"];

Querying the history

Swift

channel.history { messagesPage, error in
    let messagesPage = messagesPage!
    print(messagesPage.items.first)
    print((messagesPage.items.first as? ARTMessage)?.data) // payload for the message
    messagesPage.next { nextPage, error in
        // retrieved the next page in nextPage
    }
    print(messagesPage.hasNext) // true, there are more pages
}

Objective-C

[channel history:^(ARTPaginatedResult<ARTMessage *> *messagesPage, ARTErrorInfo *error) {
    NSLog(@"%@", messagesPage.items.firstObject);
    NSLog(@"%@", messagesPage.items.firstObject.data); // payload for the message
    NSLog(@"%lu", (unsigned long)[messagesPage.items count]); // number of messages in the current page of history
    [messagesPage next:^(ARTPaginatedResult<ARTMessage *> *nextPage, ARTErrorInfo *error) {
        // retrieved the next page in nextPage
    }];
    NSLog(@"%d", messagesPage.hasNext); // true, there are more pages
}];

Presence on a channel

Swift

channel.presence.get { membersPage, error in
    let membersPage = membersPage!
    print(membersPage.items.first)
    print((membersPage.items.first as? ARTPresenceMessage)?.data) // payload for the message
    membersPage.next { nextPage, error in
        // retrieved the next page in nextPage
    }
    print(membersPage.hasNext) // true, there are more pages
}

Objective-C

[channel.presence get:^(ARTPaginatedResult<ARTPresenceMessage *> *membersPage, ARTErrorInfo *error) {
    NSLog(@"%@", membersPage.items.firstObject);
    NSLog(@"%@", membersPage.items.firstObject.data); // payload for the message
    [membersPage next:^(ARTPaginatedResult<ARTMessage *> *nextPage, ARTErrorInfo *error) {
        // retrieved the next page in nextPage
    }];
    NSLog(@"%d", membersPage.hasNext); // true, there are more pages
}];

Querying the presence history

Swift

channel.presence.history { presencePage, error in
    let presencePage = presencePage!
    if let first = presencePage.items.first as? ARTPresenceMessage {
        print(first.clientId) // client ID of member
        presencePage.next { nextPage, error in
            // retrieved the next page in nextPage
        }
    }
}

Objective-C

[channel.presence history:^(ARTPaginatedResult<ARTPresenceMessage *> *presencePage, ARTErrorInfo *error) {
    ARTPresenceMessage *first = (ARTPresenceMessage *)presencePage.items.firstObject;
    NSLog(@"%@", first.clientId); // client ID of member
    NSLog(@"%@", first.data); // optional data payload of member
    [presencePage next:^(ARTPaginatedResult<ARTPresenceMessage *> *nextPage, ARTErrorInfo *error) {
        // retrieved the next page in nextPage
    }];
}];

Generate token

Swift

client.auth.requestToken(nil, withOptions: nil) { tokenDetails, error in
    let tokenDetails = tokenDetails!
    print(tokenDetails.token) // "xVLyHw.CLchevH3hF....MDh9ZC_Q"
    let client = ARTRest(token: tokenDetails.token)
}

Objective-C

[client.auth requestToken:nil withOptions:nil callback:^(ARTTokenDetails *tokenDetails, NSError *error) {
    NSLog(@"%@", tokenDetails.token); // "xVLyHw.CLchevH3hF....MDh9ZC_Q"
    ARTRest *client = [[ARTRest alloc] initWithToken:tokenDetails.token];
}];

### Fetching your application's stats

Swift

client.stats { statsPage, error in
    let statsPage = statsPage!
    print(statsPage.items.first)
    statsPage.next { nextPage, error in
        // retrieved the next page in nextPage
    }
}

Objective-C

[client stats:^(ARTPaginatedResult<ARTStats *> *statsPage, ARTErrorInfo *error) {
    NSLog(@"%@", statsPage.items.firstObject);
    [statsPage next:^(ARTPaginatedResult<ARTStats *> *nextPage, ARTErrorInfo *error) {
        // retrieved the next page in nextPage
    }];
}];

Fetching the Ably service time

Swift

client.time { time, error in
    print(time) // 2016-02-09 03:59:24 +0000
}

Objective-C

[client time:^(NSDate *time, NSError *error) {
    NSLog(@"%@", time); // 2016-02-09 03:59:24 +0000
}];

Support, feedback and troubleshooting

Please visit http://support.ably.io/ for access to our knowledgebase and to ask for any assistance.

You can also view the community reported Github issues.

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Ensure you have added suitable tests and the test suite is passing
5. Push to the branch (git push origin my-new-feature)
6. Create a new Pull Request

Release notes

This library uses semantic versioning. For each release, the following needs to be done:

• Replace all references of the current version number with the new version number (check this file README.md, Ably.podspec, Source/Info.plist, Source/ARTDefault.m) and commit the changes. (example: Bump commit).
• Run github_changelog_generator to automate the update of the CHANGELOG. Once the CHANGELOG has completed, manually change the Unreleased heading and link with the current version number such as v1.0.0. Also ensure that the Full Changelog link points to the new version tag instead of the HEAD. Commit this change.
• Add a tag and push to origin such as git tag v1.0.0 && git push origin v1.0.0
• Visit releases page and Add release notes.
• Remember to release an update for the CocoaPods.
• Remember to generate and attach the prebuilt framework for Carthage.

License

Copyright (c) 2015 Ably Real-time Ltd, Licensed under the Apache License, Version 2.0. Refer to LICENSE for the license terms.