Class: ROM::Mapper

Inherits:
Object
  • Object
show all
Extended by:
Plugins::ClassMethods, SettingProxy
Includes:
DSL
Defined in:
lib/rom/mapper.rb,
lib/rom/mapper/dsl.rb,
lib/rom/compat/mapper.rb,
lib/rom/mapper/model_dsl.rb,
lib/rom/mapper/attribute_dsl.rb

Overview

Mapper is a simple object that uses transformers to load relations

Defined Under Namespace

Modules: DSL, ModelDSL Classes: AttributeDSL

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(header, processor = :transformer) ⇒ Mapper

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a new instance of Mapper.



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# File 'lib/rom/mapper.rb', line 77

def initialize(header, processor = :transformer)
  processor = Mapper.processors.fetch(processor)
  @transformers = self.class.headers(header).map do |hdr|
    processor.build(self, hdr)
  end
  @header = header
end

Instance Attribute Details

#header ⇒ Header (readonly)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns header that was used to build the transformers.

Returns:

  • (Header) —

    header that was used to build the transformers



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# File 'lib/rom/mapper.rb', line 35

def header
  @header
end

#transformers ⇒ Object (readonly)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns transformers object built by a processor.

Returns:

  • (Object) —

    transformers object built by a processor



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# File 'lib/rom/mapper.rb', line 30

def transformers
  @transformers
end

Class Method Details

.build(header = self.header, processor = :transformer) ⇒ Mapper

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Build a mapper using provided processor type

Returns:



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# File 'lib/rom/mapper.rb', line 72

def self.build(header = self.header, processor = :transformer)
  new(header, processor)
end

.headers(header) ⇒ Array<Header>

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Prepares an array of headers for a potentially multistep mapper

Returns:

Raises:



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# File 'lib/rom/mapper.rb', line 60

def self.headers(header)
  return [header] if steps.empty?
  return steps.map(&:header) if attributes.empty?

  raise(MapperMisconfiguredError, "cannot mix outer attributes and steps")
end

.plugins ⇒ Object Originally defined in module Plugins::ClassMethods

Return all available plugins for the component type

.processors ⇒ Hash

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns registered processors.

Returns:

  • (Hash) —

    registered processors



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# File 'lib/rom/mapper.rb', line 40

def self.processors
  @_processors ||= {}
end

.register_processor(processor) ⇒ Hash

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Register a processor class

Returns:

  • (Hash) 


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# File 'lib/rom/mapper.rb', line 49

def self.register_processor(processor)
  name = processor.name.split("::").last.downcase.to_sym
  processors.update(name => processor)
end

.setting_mapping ⇒ Object 



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# File 'lib/rom/compat/mapper.rb', line 10

def setting_mapping
  @setting_mapper ||= ROM::Transformer.setting_mapping.merge(
    inherit_header: [],
    reject_keys: [],
    symbolize_keys: [],
    copy_keys: [],
    prefix: [],
    prefix_separator: []
  ).freeze
end

.use(name, **options) ⇒ Object Originally defined in module Plugins::ClassMethods

Include a registered plugin in this relation class

Parameters:

  • plugin (Symbol)
  • options (Hash)

Options Hash (**options):

  • :adapter (Symbol) — default: :default —

    first adapter to check for plugin

Instance Method Details

#call(relation) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Process a relation using the transformers



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# File 'lib/rom/mapper.rb', line 95

def call(relation)
  transformers.reduce(relation.to_a) { |a, e| e.call(a) }
end

#model ⇒ Class

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns optional model that is instantiated by a mapper.

Returns:

  • (Class) —

    optional model that is instantiated by a mapper



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# File 'lib/rom/mapper.rb', line 88

def model
  header.model
end