Class: LaunchDarkly::LDClient

Inherits:
Object
  • Object
show all
Includes:
Evaluation
Defined in:
lib/ldclient-rb/ldclient.rb

Overview

A client for LaunchDarkly. Client instances are thread-safe. Users should create a single client instance for the lifetime of the application.

Constant Summary

Constants included from Evaluation

Evaluation::BUILTINS, Evaluation::DATE_OPERAND, Evaluation::NUMERIC_VERSION_COMPONENTS_REGEX, Evaluation::OPERATORS, Evaluation::SEMVER_OPERAND

Instance Method Summary collapse

Methods included from Evaluation

addZeroVersionComponent, #bucket_user, #bucketable_string_value, #clause_match_user, #clause_match_user_no_segments, comparator, #eval_internal, #eval_rules, #evaluate, #get_variation, #match_any, #maybe_negate, #rule_match_user, #segment_match_user, #segment_rule_match_user, #user_value, #variation_for_user

Constructor Details

#initialize(sdk_key, config = Config.default, wait_for_sec = 5) ⇒ LDClient

Creates a new client instance that connects to LaunchDarkly. A custom configuration parameter can also supplied to specify advanced options, but for most use cases, the default configuration is appropriate.

Parameters:

  • sdk_key (String) —

    the SDK key for your LaunchDarkly account

  • config (Config) (defaults to: Config.default) —

    an optional client configuration object



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# File 'lib/ldclient-rb/ldclient.rb', line 26

def initialize(sdk_key, config = Config.default, wait_for_sec = 5)
  @sdk_key = sdk_key
  @config = config
  @store = config.feature_store

  if @config.offline? || !@config.send_events
    @event_processor = NullEventProcessor.new
  else
    @event_processor = EventProcessor.new(sdk_key, config)
  end

  if @config.use_ldd?
    @config.logger.info { "[LDClient] Started LaunchDarkly Client in LDD mode" }
    return  # requestor and update processor are not used in this mode
  end

  requestor = Requestor.new(sdk_key, config)

  if !@config.offline?
    if @config.update_processor.nil?
      if @config.stream?
        @update_processor = StreamProcessor.new(sdk_key, config, requestor)
      else
        @config.logger.info { "Disabling streaming API" }
        @config.logger.warn { "You should only disable the streaming API if instructed to do so by LaunchDarkly support" }
        @update_processor = PollingProcessor.new(config, requestor)
      end
    else
      @update_processor = @config.update_processor
    end
    @update_processor.start
  end

  if !@config.offline? && wait_for_sec > 0
    begin
      WaitUtil.wait_for_condition("LaunchDarkly client initialization", timeout_sec: wait_for_sec, delay_sec: 0.1) do
        initialized?
      end
    rescue WaitUtil::TimeoutError
      @config.logger.error { "[LDClient] Timeout encountered waiting for LaunchDarkly client initialization" }
    end
  end
end

Instance Method Details

#all_flags(user) ⇒ Object

Returns all feature flag values for the given user



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# File 'lib/ldclient-rb/ldclient.rb', line 197

def all_flags(user)
  sanitize_user(user)
  return Hash.new if @config.offline?

  unless user
    @config.logger.error { "[LDClient] Must specify user in all_flags" }
    return Hash.new
  end

  begin
    features = @store.all(FEATURES)

    # TODO rescue if necessary
    Hash[features.map{ |k, f| [k, evaluate(f, user, @store, @config.logger)[:value]] }]
  rescue => exn
    @config.logger.warn { "[LDClient] Error evaluating all flags: #{exn.inspect}. \nTrace: #{exn.backtrace}" }
    return Hash.new
  end
end

#close ⇒ void

This method returns an undefined value.

Releases all network connections and other resources held by the client, making it no longer usable



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# File 'lib/ldclient-rb/ldclient.rb', line 221

def close
  @config.logger.info { "[LDClient] Closing LaunchDarkly client..." }
  if not @config.offline?
    @update_processor.stop
  end
  @event_processor.stop
  @store.stop
end

#flush ⇒ Object 



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# File 'lib/ldclient-rb/ldclient.rb', line 70

def flush
  @event_processor.flush
end

#identify(user) ⇒ void

This method returns an undefined value.

Registers the user

Parameters:

  • The (Hash) —

    user to register



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# File 'lib/ldclient-rb/ldclient.rb', line 176

def identify(user)
  sanitize_user(user)
  @event_processor.add_event(kind: "identify", key: user[:key], user: user)
end

#initialized? ⇒ Boolean

Returns whether the client has been initialized and is ready to serve feature flag requests

Returns:

  • (Boolean) —

    true if the client has been initialized



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# File 'lib/ldclient-rb/ldclient.rb', line 85

def initialized?
  @config.offline? || @config.use_ldd? || @update_processor.initialized?
end

#secure_mode_hash(user) ⇒ Object 



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# File 'lib/ldclient-rb/ldclient.rb', line 79

def secure_mode_hash(user)
  OpenSSL::HMAC.hexdigest("sha256", @sdk_key, user[:key].to_s)
end

#toggle?(key, user, default = False) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ldclient-rb/ldclient.rb', line 74

def toggle?(key, user, default = False)
  @config.logger.warn { "[LDClient] toggle? is deprecated. Use variation instead" }
  variation(key, user, default)
end

#track(event_name, user, data) ⇒ void

This method returns an undefined value.

Tracks that a user performed an event

Parameters:

  • event_name (String) —

    The name of the event

  • user (Hash) —

    The user that performed the event. This should be the same user hash used in calls to #toggle?

  • data (Hash) —

    A hash containing any additional data associated with the event



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# File 'lib/ldclient-rb/ldclient.rb', line 189

def track(event_name, user, data)
  sanitize_user(user)
  @event_processor.add_event(kind: "custom", key: event_name, user: user, data: data)
end

#variation(key, user, default) ⇒ Object

Determines the variation of a feature flag to present to a user. At a minimum, the user hash should contain a :key .

For authenticated users, the :key should be the unique identifier for your user. For anonymous users, the :key should be a session identifier or cookie. In either case, the only requirement is that the key is unique to a user.

You can also pass IP addresses and country codes in the user hash.

The user hash can contain arbitrary custom attributes stored in a :custom sub-hash:

Attribute values in the custom hash can be integers, booleans, strings, or

lists of integers, booleans, or strings.

Examples:

Basic user hash

{key: "[email protected]"}

More complete user hash

{key: "[email protected]", ip: "127.0.0.1", country: "US"}

A user hash with custom attributes

{key: "[email protected]", custom: {customer_rank: 1000, groups: ["google", "microsoft"]}}

Parameters:

  • key (String) —

    the unique feature key for the feature flag, as shown on the LaunchDarkly dashboard

  • user (Hash) —

    a hash containing parameters for the end user requesting the flag

  • default=false —

    the default value of the flag

Returns:

  • the variation to show the user, or the default value if there’s an an error



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# File 'lib/ldclient-rb/ldclient.rb', line 121

def variation(key, user, default)
  return default if @config.offline?

  if !initialized?
    if @store.initialized?
      @config.logger.warn { "[LDClient] Client has not finished initializing; using last known values from feature store" }
    else
      @config.logger.error { "[LDClient] Client has not finished initializing; feature store unavailable, returning default value" }
      @event_processor.add_event(kind: "feature", key: key, value: default, default: default, user: user)
      return default
    end
  end

  sanitize_user(user) if !user.nil?
  feature = @store.get(FEATURES, key)

  if feature.nil?
    @config.logger.info { "[LDClient] Unknown feature flag #{key}. Returning default value" }
    @event_processor.add_event(kind: "feature", key: key, value: default, default: default, user: user)
    return default
  end

  unless user
    @config.logger.error { "[LDClient] Must specify user" }
    @event_processor.add_event(make_feature_event(feature, user, nil, default, default))
    return default
  end

  begin
    res = evaluate(feature, user, @store, @config.logger)
    if !res[:events].nil?
      res[:events].each do |event|
        @event_processor.add_event(event)
      end
    end
    value = res[:value]
    if value.nil?
      @config.logger.debug { "[LDClient] Result value is null in toggle" }
      value = default
    end
    @event_processor.add_event(make_feature_event(feature, user, res[:variation], value, default))
    return value
  rescue => exn
    @config.logger.warn { "[LDClient] Error evaluating feature flag: #{exn.inspect}. \nTrace: #{exn.backtrace}" }
    @event_processor.add_event(make_feature_event(feature, user, nil, default, default))
    return default
  end
end