class Ably::Rest::Channel
Enables messages to be published and historic messages to be retrieved for a channel.
Constants
- IDEMPOTENT_LIBRARY_GENERATED_ID_LENGTH
Attributes
Ably
client associated with this channel @return [Ably::Realtime::Client] @api private
The channel name. @return [String]
A {Ably::Rest::Channel::PushChannel} object @spec RSH4 @return [Ably::Rest::Channel::PushChannel] @api private
Public Class Methods
Source
# File lib/ably/rest/channel.rb, line 33 def initialize(client, name, channel_options = {}) name = (ensure_utf_8 :name, name) @options = Ably::Models::ChannelOptions(channel_options) @client = client @name = name @push = PushChannel.new(self) end
Initialize a new Channel
object
@param client [Ably::Rest::Client] @param name [String] The name of the channel @param channel_options [Hash, Ably::Models::ChannelOptions
] A hash of options or a {Ably::Models::ChannelOptions}
Public Instance Methods
Source
# File lib/ably/rest/channel.rb, line 132 def history(options = {}) url = "#{base_path}/messages" options = { :direction => :backwards, :limit => 100 }.merge(options) [:start, :end].each { |option| options[option] = as_since_epoch(options[option]) if options.has_key?(option) } raise ArgumentError, ":end must be equal to or after :start" if options[:start] && options[:end] && (options[:start] > options[:end]) paginated_options = { coerce_into: 'Ably::Models::Message', async_blocking_operations: options.delete(:async_blocking_operations), } response = client.get(url, options) Ably::Models::PaginatedResult.new(response, url, client, paginated_options) do |message| message.tap do |msg| decode_message msg end end end
Retrieves a {Ably::Models::PaginatedResult} object, containing an array of historical {Ably::Models::Message} objects for the channel. If the channel is configured to persist messages, then messages can be retrieved from history for up to 72 hours in the past. If not, messages can only be retrieved from history for up to two minutes in the past.
@spec RSL2a
@param [Hash] options the options for the message history request @option options [Integer,Time] :start The time from which messages are retrieved, specified as milliseconds since the Unix epoch. RSL2b1 @option options [Integer,Time] :end The time until messages are retrieved, specified as milliseconds since the Unix epoch. RSL2b1 @option options [Symbol] :direction The order for which messages are returned in. Valid values are backwards which orders messages from most recent to oldest, or forwards which orders messages from oldest to most recent. The default is backwards. RSL2b2 @option options [Integer] :limit An upper limit on the number of messages returned. The default is 100, and the maximum is 1000. RSL2b3
@return [Ably::Models::PaginatedResult<Ably::Models::Message>] A {Ably::Models::PaginatedResult} object containing an array of {Ably::Models::Message} objects.
Source
# File lib/ably/rest/channel.rb, line 159 def presence @presence ||= Presence.new(client, self) end
A {Ably::Rest::Presence} object. @spec RSL3 @return [Ably::Rest::Presence]
Source
# File lib/ably/rest/channel.rb, line 77 def publish(name, data = nil, attributes = {}) qs_params = nil qs_params = data if name.kind_of?(Enumerable) || name.kind_of?(Ably::Models::Message) messages = build_messages(name, data, attributes) # (RSL1a, RSL1b) if messages.sum(&:size) > (max_message_size = client.max_message_size || Ably::Rest::Client::MAX_MESSAGE_SIZE) raise Ably::Exceptions::MaxMessageSizeExceeded.new("Maximum message size exceeded #{max_message_size} bytes.") end payload = messages.map do |message| Ably::Models::Message(message.dup).tap do |msg| msg.encode client.encoders, options next if msg.client_id.nil? if msg.client_id == '*' raise Ably::Exceptions::IncompatibleClientId.new('Wildcard client_id is reserved and cannot be used when publishing messages') end unless client.auth.can_assume_client_id?(msg.client_id) raise Ably::Exceptions::IncompatibleClientId.new("Cannot publish with client_id '#{msg.client_id}' as it is incompatible with the current configured client_id '#{client.client_id}'") end end.as_json end.tap do |payload| if client.idempotent_rest_publishing # We cannot mutate for idempotent publishing if one or more messages already has an ID if payload.all? { |msg| !msg['id'] } # Mutate the JSON to support idempotent publishing where a Message.id does not exist idempotent_publish_id = SecureRandom.base64(IDEMPOTENT_LIBRARY_GENERATED_ID_LENGTH) payload.each_with_index do |msg, idx| msg['id'] = "#{idempotent_publish_id}:#{idx}" end end end end options = qs_params ? { qs_params: qs_params } : {} response = client.post("#{base_path}/publish", payload.length == 1 ? payload.first : payload, options) [201, 204].include?(response.status) end
Publishes a message to the channel. A callback may optionally be passed in to this call to be notified of success or failure of the operation.
@spec RSL1
@param name [String, Array<Ably::Models::Message|Hash>, Ably::Models::Message
, nil] The event name of the message to publish, or an Array of [Ably::Model::Message] objects or [Hash] objects with :name
and :data
pairs, or a single Ably::Model::Message object @param data [String, Array, Hash, nil] The message payload unless an Array of [Ably::Model::Message] objects passed in the first argument, in which case an optional hash of query parameters @param attributes [Hash, nil] Optional additional message attributes such as :extras, :id, :client_id or :connection_id, applied when name attribute is nil or a string (Deprecated, will be removed in 2.0 in favour of constructing a Message object) @return [Boolean] true if the message was published, otherwise false
@example
# Publish a single message with (name, data) form channel.publish 'click', { x: 1, y: 2 } # Publish a single message with single Hash form message = { name: 'click', data: { x: 1, y: 2 } } channel.publish message # Publish an array of message Hashes form messages = [ { name: 'click', data: { x: 1, y: 2 } }, { name: 'click', data: { x: 2, y: 3 } } ] channel.publish messages # Publish an array of Ably::Models::Message objects form messages = [ Ably::Models::Message(name: 'click', data: { x: 1, y: 2 }) Ably::Models::Message(name: 'click', data: { x: 2, y: 3 }) ] channel.publish messages # Publish a single Ably::Models::Message object form message = Ably::Models::Message(name: 'click', data: { x: 1, y: 2 }) channel.publish message
Source
# File lib/ably/rest/channel.rb, line 167 def set_options(channel_options) @options = Ably::Models::ChannelOptions(channel_options) end
Sets the {Ably::Models::ChannelOptions} for the channel. @spec RSL7 @param channel_options [Hash, Ably::Models::ChannelOptions
] A hash of options or a {Ably::Models::ChannelOptions} @return [Ably::Models::ChannelOptions]
Source
# File lib/ably/rest/channel.rb, line 175 def status Ably::Models::ChannelDetails.new(client.get(base_path).body) end
Retrieves a {Ably::Models::ChannelDetails} object for the channel, which includes status and occupancy metrics. @spec RSL8 @return [Ably::Models::ChannelDetails] A {Ably::Models::ChannelDetails} object.
Private Instance Methods
Source
# File lib/ably/rest/channel.rb, line 181 def base_path "/channels/#{URI.encode_www_form_component(name)}" end
Source
# File lib/ably/rest/channel.rb, line 185 def decode_message(message) message.decode client.encoders, options rescue Ably::Exceptions::CipherError, Ably::Exceptions::EncoderError => e client.logger.error { "Decoding Error on channel '#{name}', message event name '#{message.name}'. #{e.class.name}: #{e.message}" } end