class Flipper::Adapters::ActiveRecord

Constants

VALUE_TO_TEXT_WARNING

Public Class Methods

new(options = {}) click to toggle source

Public: Initialize a new ActiveRecord adapter instance.

name - The Symbol name for this adapter. Optional (default :active_record) feature_class - The AR class responsible for the features table. gate_class - The AR class responsible for the gates table.

Allowing the overriding of name is so you can differentiate multiple instances of this adapter from each other, if, for some reason, that is a thing you do.

Allowing the overriding of the default feature/gate classes means you can roll your own tables and what not, if you so desire.

# File lib/flipper/adapters/active_record.rb, line 60
def initialize(options = {})
  @name = options.fetch(:name, :active_record)
  @feature_class = options.fetch(:feature_class) { Feature }
  @gate_class = options.fetch(:gate_class) { Gate }

  warn VALUE_TO_TEXT_WARNING if value_not_text?
end

Public Instance Methods

add(feature) click to toggle source

Public: Adds a feature to the set of known features.

# File lib/flipper/adapters/active_record.rb, line 74
def add(feature)
  with_connection(@feature_class) do
    @feature_class.transaction(requires_new: true) do
      begin
        # race condition, but add is only used by enable/disable which happen
        # super rarely, so it shouldn't matter in practice
        unless @feature_class.where(key: feature.key).exists?
          @feature_class.create!(key: feature.key)
        end
      rescue ::ActiveRecord::RecordNotUnique
        # already added
      end
    end
  end

  true
end
clear(feature) click to toggle source

Public: Clears the gate values for a feature.

# File lib/flipper/adapters/active_record.rb, line 104
def clear(feature)
  with_connection(@gate_class) { @gate_class.where(feature_key: feature.key).destroy_all }
  true
end
disable(feature, gate, thing) click to toggle source

Public: Disables a gate for a given thing.

feature - The Flipper::Feature for the gate. gate - The Flipper::Gate to disable. thing - The Flipper::Type being disabled for the gate.

Returns true.

# File lib/flipper/adapters/active_record.rb, line 192
def disable(feature, gate, thing)
  case gate.data_type
  when :boolean
    clear(feature)
  when :integer
    set(feature, gate, thing)
  when :json
    delete(feature, gate)
  when :set
    with_connection(@gate_class) do
      @gate_class.where(feature_key: feature.key, key: gate.key, value: thing.value).destroy_all
    end
  else
    unsupported_data_type gate.data_type
  end

  true
end
enable(feature, gate, thing) click to toggle source

Public: Enables a gate for a given thing.

feature - The Flipper::Feature for the gate. gate - The Flipper::Gate to enable. thing - The Flipper::Type being enabled for the gate.

Returns true.

# File lib/flipper/adapters/active_record.rb, line 168
def enable(feature, gate, thing)
  case gate.data_type
  when :boolean
    set(feature, gate, thing, clear: true)
  when :integer
    set(feature, gate, thing)
  when :json
    set(feature, gate, thing, json: true)
  when :set
    enable_multi(feature, gate, thing)
  else
    unsupported_data_type gate.data_type
  end

  true
end
features() click to toggle source

Public: The set of known features.

# File lib/flipper/adapters/active_record.rb, line 69
def features
  with_connection(@feature_class) { @feature_class.distinct.pluck(:key).to_set }
end
get(feature) click to toggle source

Public: Gets the values for all gates for a given feature.

Returns a Hash of Flipper::Gate#key => value.

# File lib/flipper/adapters/active_record.rb, line 112
def get(feature)
  gates = with_connection(@gate_class) { @gate_class.where(feature_key: feature.key).pluck(:key, :value) }
  result_for_gates(feature, gates)
end
get_all() click to toggle source
# File lib/flipper/adapters/active_record.rb, line 134
def get_all
  with_connection(@feature_class) do |connection|
    # query the gates from the db in a single query
    features = ::Arel::Table.new(@feature_class.table_name.to_sym)
    gates = ::Arel::Table.new(@gate_class.table_name.to_sym)
    rows_query = features.join(gates, ::Arel::Nodes::OuterJoin)
      .on(features[:key].eq(gates[:feature_key]))
      .project(features[:key].as('feature_key'), gates[:key], gates[:value])
    gates = connection.select_rows(rows_query)

    # group the gates by feature key
    grouped_gates = gates.inject({}) do |hash, (feature_key, key, value)|
      hash[feature_key] ||= []
      hash[feature_key] << [key, value]
      hash
    end

    # build up the result hash
    result = Hash.new { |hash, key| hash[key] = default_config }
    features = grouped_gates.keys.map { |key| Flipper::Feature.new(key, self) }
    features.each do |feature|
      result[feature.key] = result_for_gates(feature, grouped_gates[feature.key])
    end
    result
  end
end
get_multi(features) click to toggle source
# File lib/flipper/adapters/active_record.rb, line 117
def get_multi(features)
  with_connection(@gate_class) do
    gates = @gate_class.where(feature_key: features.map(&:key)).pluck(:feature_key, :key, :value)
    grouped_gates = gates.inject({}) do |hash, (feature_key, key, value)|
      hash[feature_key] ||= []
      hash[feature_key] << [key, value]
      hash
    end

    result = {}
    features.each do |feature|
      result[feature.key] = result_for_gates(feature, grouped_gates[feature.key])
    end
    result
  end
end
remove(feature) click to toggle source

Public: Removes a feature from the set of known features.

# File lib/flipper/adapters/active_record.rb, line 93
def remove(feature)
  with_connection(@feature_class) do
    @feature_class.transaction do
      @feature_class.where(key: feature.key).destroy_all
      clear(feature)
    end
  end
  true
end
unsupported_data_type(data_type) click to toggle source

Private

# File lib/flipper/adapters/active_record.rb, line 212
def unsupported_data_type(data_type)
  raise "#{data_type} is not supported by this adapter"
end

Private Instance Methods

delete(feature, gate) click to toggle source
# File lib/flipper/adapters/active_record.rb, line 244
def delete(feature, gate)
  @gate_class.where(feature_key: feature.key, key: gate.key).destroy_all
end
enable_multi(feature, gate, thing) click to toggle source
# File lib/flipper/adapters/active_record.rb, line 248
def enable_multi(feature, gate, thing)
  with_connection(@gate_class) do |connection|
    begin
      connection.transaction(requires_new: true) do
        @gate_class.create! do |g|
          g.feature_key = feature.key
          g.key = gate.key
          g.value = thing.value.to_s
        end
      end
    rescue ::ActiveRecord::RecordNotUnique
      # already added so move on with life
    end
  end

  nil
end
result_for_gates(feature, gates) click to toggle source
# File lib/flipper/adapters/active_record.rb, line 266
def result_for_gates(feature, gates)
  result = {}
  gates ||= []
  feature.gates.each do |gate|
    result[gate.key] =
      case gate.data_type
      when :boolean, :integer
        if row = gates.detect { |key, value| !key.nil? && key.to_sym == gate.key }
          row.last
        end
      when :json
        if row = gates.detect { |key, value| !key.nil? && key.to_sym == gate.key }
          Typecast.from_json(row.last)
        end
      when :set
        gates.select { |key, value| !key.nil? && key.to_sym == gate.key }.map(&:last).to_set
      else
        unsupported_data_type gate.data_type
      end
  end
  result
end
set(feature, gate, thing, options = {}) click to toggle source
# File lib/flipper/adapters/active_record.rb, line 218
def set(feature, gate, thing, options = {})
  clear_feature = options.fetch(:clear, false)
  json_feature = options.fetch(:json, false)

  raise VALUE_TO_TEXT_WARNING if json_feature && value_not_text?

  with_connection(@gate_class) do
    @gate_class.transaction(requires_new: true) do
      clear(feature) if clear_feature
      delete(feature, gate)
      begin
        @gate_class.create! do |g|
          g.feature_key = feature.key
          g.key = gate.key
          g.value = json_feature ? Typecast.to_json(thing.value) : thing.value.to_s
        end
      rescue ::ActiveRecord::RecordNotUnique
        # assume this happened concurrently with the same thing and its fine
        # see https://github.com/flippercloud/flipper/issues/544
      end
    end
  end

  nil
end
value_not_text?() click to toggle source

Check if value column is text instead of string See github.com/flippercloud/flipper/pull/692

# File lib/flipper/adapters/active_record.rb, line 291
def value_not_text?
  @gate_class.column_for_attribute(:value).type != :text
rescue ::ActiveRecord::ActiveRecordError => error
  # If the table doesn't exist, the column doesn't exist either
  warn "#{error.message}. You likely need to run `rails g flipper:active_record` and/or `rails db:migrate`."
end
with_connection(model = @feature_class, &block) click to toggle source
# File lib/flipper/adapters/active_record.rb, line 298
def with_connection(model = @feature_class, &block)
  model.connection_pool.with_connection(&block)
end