Module: Serega::SeregaPlugins::Batch

Defined in:
lib/serega/plugins/batch/batch.rb,
lib/serega/plugins/batch/lib/loader.rb,
lib/serega/plugins/batch/lib/loaders.rb,
lib/serega/plugins/batch/lib/plugins_extensions.rb,
lib/serega/plugins/batch/lib/validations/check_opt_batch.rb,
lib/serega/plugins/batch/lib/validations/check_batch_opt_key.rb,
lib/serega/plugins/batch/lib/validations/check_batch_opt_loader.rb

Overview

Plugin that can be used to load attributes values in batches. Each batch loader accepts list of selected keys, context and current attribute point. Each batch loader must return Hash with values grouped by provided keys. There are specific :default option that can be used to add default value for missing key.

Examples:

class PostSerializer < Serega
  plugin :batch

  # Define batch loader via callable class, it must accept three args (keys, context, map_point)
  attribute :comments_count, batch: { key: :id, loader: PostCommentsCountBatchLoader, default: 0}

  # Define batch loader via Symbol, later we should define this loader via config.batch_loaders.define(:posts_comments_counter) { ... }
  attribute :comments_count, batch: { key: :id, loader: :posts_comments_counter, default: 0}

  # Define batch loader with serializer
  attribute :comments, serializer: CommentSerializer, batch: { key: :id, loader: :posts_comments, default: []}

  # Resulted block must return hash like { key => value(s) }
  config.batch_loaders.define(:posts_comments_counter) do |keys|
    Comment.group(:post_id).where(post_id: keys).count
  end

  # We can return objects that will be automatically serialized if attribute defined with :serializer
  # Parameter `context` can be used when loading batch
  # Parameter `map_point` can be used to find nested attributes that will be serialized (`map_point.preloads`)
  config.batch_loaders.define(:posts_comments) do |keys, context, map_point|
    Comment.where(post_id: keys).where(is_spam: false).group_by(&:post_id)
  end
end

Defined Under Namespace

Modules: AttributeInstanceMethods, CheckAttributeParamsInstanceMethods, ClassMethods, ConfigInstanceMethods, InstanceMethods, MapPointInstanceMethods, PluginsExtensions, SeregaObjectSerializerInstanceMethods Classes: BatchLoadersConfig, BatchModel, CheckBatchOptKey, CheckBatchOptLoader, CheckOptBatch, SeregaBatchLoader, SeregaBatchLoaders

Class Method Summary collapse

Class Method Details

.after_load_plugin(serializer_class, **opts) ⇒ void

This method returns an undefined value.

Runs callbacks after plugin was attached

Parameters:

  • serializer_class (Class<Serega>) —

    Current serializer class

  • opts (Hash) —

    loaded plugins opts



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# File 'lib/serega/plugins/batch/batch.rb', line 75

def self.after_load_plugin(serializer_class, **opts)
  config = serializer_class.config
  config.attribute_keys << :batch
  config.opts[:batch] = {loaders: {}}
  serializer_class::SeregaConfig.include(ConfigInstanceMethods)

  batch_loaders_class = Class.new(SeregaBatchLoaders)
  batch_loaders_class.serializer_class = serializer_class
  serializer_class.const_set(:SeregaBatchLoaders, batch_loaders_class)

  batch_loader_class = Class.new(SeregaBatchLoader)
  batch_loader_class.serializer_class = serializer_class
  serializer_class.const_set(:SeregaBatchLoader, batch_loader_class)

  if serializer_class.plugin_used?(:activerecord_preloads)
    require_relative "./lib/plugins_extensions"
    serializer_class::SeregaBatchLoader.include(PluginsExtensions::ActiveRecordPreloads::BatchLoaderInstanceMethods)
  end

  if serializer_class.plugin_used?(:formatters)
    require_relative "./lib/plugins_extensions"
    serializer_class::SeregaBatchLoader.include(PluginsExtensions::Formatters::BatchLoaderInstanceMethods)
  end
end

.load_plugin(serializer_class, **_opts) ⇒ void

This method returns an undefined value.

Applies plugin code to specific serializer

Parameters:

  • serializer_class (Class<Serega>) —

    Current serializer class

  • _opts (Hash) —

    Loaded plugins options



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# File 'lib/serega/plugins/batch/batch.rb', line 52

def self.load_plugin(serializer_class, **_opts)
  require_relative "./lib/loader"
  require_relative "./lib/loaders"
  require_relative "./lib/validations/check_batch_opt_key"
  require_relative "./lib/validations/check_batch_opt_loader"
  require_relative "./lib/validations/check_opt_batch"

  serializer_class.extend(ClassMethods)
  serializer_class.include(InstanceMethods)
  serializer_class::CheckAttributeParams.include(CheckAttributeParamsInstanceMethods)
  serializer_class::SeregaAttribute.include(AttributeInstanceMethods)
  serializer_class::SeregaMapPoint.include(MapPointInstanceMethods)
  serializer_class::SeregaObjectSerializer.include(SeregaObjectSerializerInstanceMethods)
end

.plugin_name ⇒ Symbol

Returns plugin name

Returns:

  • (Symbol) —

    Plugin name



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# File 'lib/serega/plugins/batch/batch.rb', line 40

def self.plugin_name
  :batch
end