# [Ably](https://ably.com) [![Gem Version](https://img.shields.io/gem/v/ably?style=flat)](https://img.shields.io/gem/v/ably?style=flat) [![Coverage Status](https://coveralls.io/repos/ably/ably-ruby/badge.svg)](https://coveralls.io/r/ably/ably-ruby) _[Ably](https://ably.com) is the platform that powers synchronized digital experiences in realtime. Whether attending an event in a virtual venue, receiving realtime financial information, or monitoring live car performance data – consumers simply expect realtime digital experiences as standard. Ably provides a suite of APIs to build, extend, and deliver powerful digital experiences in realtime for more than 250 million devices across 80 countries each month. Organizations like Bloomberg, HubSpot, Verizon, and Hopin depend on Ably’s platform to offload the growing complexity of business-critical realtime data synchronization at global scale. For more information, see the [Ably documentation](https://ably.com/documentation)._ This is a Ruby client library for Ably. The library currently targets the [Ably 1.1 client library specification](https://ably.com/documentation/client-lib-development-guide/features/). You can see the complete list of features this client library supports in [our client library SDKs feature support matrix](https://ably.com/download/sdk-feature-support-matrix). ## Supported platforms This SDK supports Ruby 1.9.3+. For eventmachine and Ruby 3.0 note please visit [Ruby 3.0 support](#ruby-30-support) section. As of v1.1.5 this library requires `libcurl` as a system dependency. On most systems this is already installed but in rare cases where it isn't (for example debian-slim Docker images such as ruby-slim) you will need to install it yourself. On debian you can install it with the command `sudo apt-get install libcurl4`. We regression-test the SDK against a selection of Ruby versions (which we update over time, but usually consists of mainstream and widely used versions). Please refer to [.github/workflows/check.yml](./.github/workflows/check.yml) for the set of versions that currently undergo CI testing. If you find any compatibility issues, please [do raise an issue](https://github.com/ably/ably-ruby/issues/new) in this repository or [contact Ably customer support](https://ably.com/support/) for advice. ## Documentation Visit https://ably.com/documentation for a complete API reference and code examples. ## Installation The client library is available as a [gem from RubyGems.org](https://rubygems.org/gems/ably). Add this line to your application's Gemfile: gem 'ably' And then install this Bundler dependency: $ bundle Or install it yourself as: $ gem install ably ### Using with Rails or Sinatra This `ably` gem provides both a [Realtime](https://ably.com/documentation/realtime/usage) and [REST](https://ably.com/documentation/rest/usage) version of the Ably library. Realtime depends on EventMachine to provide an asynchronous evented framework to run the library in, whereas the REST library depends only on synchronous libraries such as Faraday. If you are using Ably within your Rails or Sinatra apps, more often than not, you probably want to use the REST only version of the library that has no dependency on EventMachine and provides a synchronous API that you will be used to using within Rails and Sinatra. [See the REST only Ruby version of the Ably library](https://github.com/ably/ably-ruby-rest). ## Using the Realtime API ### Introduction All examples must be run within an [EventMachine](https://github.com/eventmachine/eventmachine) [reactor](https://github.com/eventmachine/eventmachine/wiki/General-Introduction) as follows: ```ruby EventMachine.run do # ... end ``` All examples assume a client has been created using one of the following: ```ruby # basic auth with an API key client = Ably::Realtime.new(key: 'xxxxx') # using token auth client = Ably::Realtime.new(token: 'xxxxx') ``` If you do not have an API key, [sign up for a free API key now](https://ably.com/signup) ### Connection Successful connection: ```ruby client.connection.connect do # successful connection end ``` Failed connection: ```ruby connection_result = client.connection.connect connection_result.errback = Proc.new do # failed connection end ``` Subscribing to connection state changes: ```ruby client.connection.on do |state_change| state_change.current #=> :connected state_change.previous #=> :connecting end ``` ### Subscribing to a channel Given a channel is created as follows: ```ruby channel = client.channels.get('test') ``` Subscribe to all events: ```ruby channel.subscribe do |message| message.name #=> "greeting" message.data #=> "Hello World!" end ``` Only certain events: ```ruby channel.subscribe('myEvent') do |message| message.name #=> "myEvent" message.data #=> "myData" end ``` ### Publishing a message to a channel ```ruby channel.publish('greeting', 'Hello World!') ``` ### Querying the History ```ruby channel.history do |messages_page| messages_page #=> # messages_page.items.first # # messages_page.items.first.data # payload for the message messages_page.items.length # number of messages in the current page of history messages_page.next do |next_page| next_page #=> the next page => # end messages_page.has_next? # false, there are more pages end ``` ### Presence on a channel ```ruby channel.presence.enter(data: 'metadata') do |presence| presence.get do |members| members #=> [Array of members present] end end ``` ### Subscribing to presence events ```ruby channel.presence.subscribe do |member| member #=> { action: :enter, client_id: 'bob' } end ``` ### Querying the Presence History ```ruby channel.presence.history do |presence_page| presence_page.items.first.action # Any of :enter, :update or :leave presence_page.items.first.client_id # client ID of member presence_page.items.first.data # optional data payload of member presence_page.next do |next_page| next_page #=> the next page => # end presence_page.has_next? # false, there are more pages end ``` ### Symmetric end-to-end encrypted payloads on a channel When a 128 bit or 256 bit key is provided to the library, all payloads are encrypted and decrypted automatically using that key on the channel. The secret key is never transmitted to Ably and thus it is the developer's responsibility to distribute a secret key to both publishers and subscribers. ```ruby secret_key = Ably::Util::Crypto.generate_random_key channel = client.channels.get('test', cipher: { key: secret_key }) channel.subscribe do |message| message.data #=> "sensitive data (encrypted before being published)" end channel.publish "name (not encrypted)", "sensitive data (encrypted before being published)" ``` ## Using the REST API ### Introduction Unlike the Realtime API, all calls are synchronous and are not run within [EventMachine](https://github.com/eventmachine/eventmachine). All examples assume a client and/or channel has been created as follows: ```ruby client = Ably::Rest.new(key: 'xxxxx') channel = client.channel('test') ``` ### Publishing a message to a channel ```ruby channel.publish('myEvent', 'Hello!') #=> true ``` ### Querying the History ```ruby messages_page = channel.history #=> # messages_page.items.first #=> # messages_page.items.first.data # payload for the message messages_page.next # retrieves the next page => # messages_page.has_next? # false, there are more pages ``` ### Current presence members on a channel ```ruby members_page = channel.presence.get # => # members_page.items.first # first member present in this page => # members_page.items.first.client_id # client ID of first member present members_page.next # retrieves the next page => # members_page.has_next? # false, there are more pages ``` ### Querying the presence history ```ruby presence_page = channel.presence.history #=> # presence_page.items.first #=> # presence_page.items.first.client_id # client ID of first member presence_page.next # retrieves the next page => # ``` ### Symmetric end-to-end encrypted payloads on a channel When a 128 bit or 256 bit key is provided to the library, all payloads are encrypted and decrypted automatically using that key on the channel. The secret key is never transmitted to Ably and thus it is the developer's responsibility to distribute a secret key to both publishers and subscribers. ```ruby secret_key = Ably::Util::Crypto.generate_random_key channel = client.channels.get('test', cipher: { key: secret_key }) channel.publish nil, "sensitive data" # data will be encrypted before publish messages_page = channel.history messages_page.items.first.data #=> "sensitive data" ``` ### Generate a Token Tokens are issued by Ably and are readily usable by any client to connect to Ably: ```ruby token_details = client.auth.request_token # => # token_details.token # => "xVLyHw.CLchevH3hF....MDh9ZC_Q" client = Ably::Rest.new(token: token_details) ``` ### Generate a TokenRequest Token requests are issued by your servers and signed using your private API key. This is the preferred method of authentication as no secrets are ever shared, and the token request can be issued to trusted clients without communicating with Ably. ```ruby token_request = client.auth.create_token_request(ttl: 3600, client_id: 'jim') # => {"id"=>..., # "clientId"=>"jim", # "ttl"=>3600, # "timestamp"=>..., # "capability"=>"{\"*\":[\"*\"]}", # "nonce"=>..., # "mac"=>...} client = Ably::Rest.new(token: token_request) ``` ### Fetching your application's stats ```ruby stats_page = client.stats #=> # stats_page.items.first = # stats_page.next # retrieves the next page => # ``` ### Fetching the Ably service time ```ruby client.time #=> 2013-12-12 14:23:34 +0000 ``` ## Ruby 3.0 support If you cannot install ably realtime gem because of eventmachine openssl problems, please try to set your `openssl-dir`, i.e.: ```ruby gem install eventmachine -- --with-openssl-dir=/usr/local/opt/openssl@1.1 ``` More about eventmachine and ruby 3.0 support here https://github.com/eventmachine/eventmachine/issues/932 ## Dependencies If you only need to use the REST features of this library and do not want EventMachine as a dependency, then you should consider using the [Ably Ruby REST gem](https://rubygems.org/gems/ably-rest). ## Upgrading from an older version - [Release and upgrade notes for v0.8 -> v1.0](https://github.com/ably/docs/issues/235) ## Support, feedback and troubleshooting Please visit https://ably.com/support for access to our knowledgebase and to ask for any assistance. You can also view the [community reported Github issues](https://github.com/ably/ably-ruby/issues). To see what has changed in recent versions of Bundler, see the [CHANGELOG](CHANGELOG.md). ## Contributing 1. Fork it 2. When pulling to local, make sure to also pull the `ably-common` repo (`git submodule init && git submodule update`) 3. Create your feature branch (`git checkout -b my-new-feature`) 4. Commit your changes (`git commit -am 'Add some feature'`) 5. Ensure you have added suitable tests and the test suite is passing(`bundle exec rspec`) 6. Push to the branch (`git push origin my-new-feature`) 7. Create a new Pull Request ## Release process This library uses [semantic versioning](http://semver.org/). For each release, the following needs to be done: * Update the version number in [version.rb](./lib/ably/version.rb) and commit the change. * Run [`github_changelog_generator`](https://github.com/skywinder/Github-Changelog-Generator) to automate the update of the [CHANGELOG](./CHANGELOG.md). Once the `CHANGELOG` update 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`. Ideally, run `rake doc:spec` to generate a new [spec file](./SPEC.md). Then commit these changes. * Add a tag and push to origin such as `git tag v1.0.0 && git push origin v1.0.0` * Visit [https://github.com/ably/ably-ruby/tags](https://github.com/ably/ably-ruby/tags) and `Add release notes` for the release including links to the changelog entry. * Run `rake release` to publish the gem to [Rubygems](https://rubygems.org/gems/ably) * Release the [REST-only library `ably-ruby-rest`](https://github.com/ably/ably-ruby-rest#release-process)