Class: Shale::Mapper

Inherits:
Type::Complex show all
Defined in:
lib/shale/mapper.rb

Overview

Base class used for mapping

Examples:

class Address < Shale::Mapper
  attribute :city, :string
  attribute :street, :string
  attribute :state, :string
  attribute :zip, :string
end

class Person < Shale::Mapper
  attribute :first_name, :string
  attribute :last_name, :string
  attribute :age, :integer
  attribute :address, Address
end

person = Person.from_json(%{
  {
    "first_name": "John",
    "last_name": "Doe",
    "age": 55,
    "address": {
      "city": "London",
      "street": "Oxford Street",
      "state": "London",
      "zip": "E1 6AN"
    }
  }
})

person.to_json

Class Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Type::Complex

as_xml, from_csv, from_json, from_toml, from_xml, from_yaml, of_xml, to_csv, #to_csv, #to_hash, #to_json, to_json, to_toml, #to_toml, to_xml, #to_xml, to_yaml, #to_yaml

Methods inherited from Type::Value

as_csv, as_hash, as_json, as_toml, as_xml, as_xml_value, as_yaml, cast, of_csv, of_hash, of_json, of_toml, of_xml, of_yaml

Constructor Details

#initialize(**props) ⇒ Mapper

Initialize instance with properties

Examples:

Person.new(
  first_name: 'John',
  last_name: 'Doe',
  address: Address.new(city: 'London')
)
# => #<Person:0x00007f82768a2370
        @first_name="John",
        @last_name="Doe"
        @address=#<Address:0x00007fe9cf0f57d8 @city="London">>

Parameters:

  • props (Hash) —

    Properties

Raises:



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# File 'lib/shale/mapper.rb', line 369

def initialize(**props)
  super()

  unless props.empty?
    unknown_attributes = props.keys - self.class.attributes.keys

    unless unknown_attributes.empty?
      raise UnknownAttributeError.new(self.class.to_s, unknown_attributes[0].to_s)
    end
  end

  self.class.attributes.each do |name, attribute|
    if props.key?(name)
      value = props[name]
    elsif attribute.default
      value = attribute.default.call
    end

    send(attribute.setter, value)
  end
end

Class Attribute Details

.attributes ⇒ Hash<Symbol, Shale::Attribute> (readonly)

Return attributes Hash

Returns:



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# File 'lib/shale/mapper.rb', line 62

def attributes
  @attributes
end

.csv_mapping ⇒ Shale::Mapping::Dict (readonly)

Return CSV mapping object

Returns:



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# File 'lib/shale/mapper.rb', line 97

def csv_mapping
  @csv_mapping
end

.hash_mapping ⇒ Shale::Mapping::Dict (readonly)

Return Hash mapping object

Returns:



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# File 'lib/shale/mapper.rb', line 69

def hash_mapping
  @hash_mapping
end

.json_mapping ⇒ Shale::Mapping::Dict (readonly)

Return JSON mapping object

Returns:



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# File 'lib/shale/mapper.rb', line 76

def json_mapping
  @json_mapping
end

.toml_mapping ⇒ Shale::Mapping::Dict (readonly)

Return TOML mapping object

Returns:



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# File 'lib/shale/mapper.rb', line 90

def toml_mapping
  @toml_mapping
end

.xml_mapping ⇒ Shale::Mapping::XML (readonly)

Return XML mapping object

Returns:

  • (Shale::Mapping::XML) 


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# File 'lib/shale/mapper.rb', line 104

def xml_mapping
  @xml_mapping
end

.yaml_mapping ⇒ Shale::Mapping::Dict (readonly)

Return YAML mapping object

Returns:



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# File 'lib/shale/mapper.rb', line 83

def yaml_mapping
  @yaml_mapping
end

Class Method Details

.attribute(name, type, collection: false, default: nil) ⇒ Object

Define attribute on class

Examples:

class Person < Shale::Mapper
  attribute :first_name, :string
  attribute :last_name, :string
  attribute :age, :integer, default: -> { 1 }
  attribute :hobbies, :string, collection: true
end

person = Person.new

person.first_name # => nil
person.first_name = 'John'
person.first_name # => 'John'

person.age # => 1

person.hobbies << 'Dancing'
person.hobbies # => ['Dancing']

Parameters:

  • name (Symbol) —

    Name of the attribute

  • type (Symbol, Class<Shale::Type::Value>) —

    Type of the attribute

  • collection (Boolean) (defaults to: false) —

    Is the attribute a collection

  • default (Proc) (defaults to: nil) —

    Default value for the attribute

Raises:



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# File 'lib/shale/mapper.rb', line 175

def attribute(name, type, collection: false, default: nil)
  name = name.to_sym

  unless default.nil? || default.respond_to?(:call)
    raise DefaultNotCallableError.new(to_s, name)
  end

  if type.is_a?(Symbol)
    type = Type.lookup(type)
  end

  @attributes[name] = Attribute.new(name, type, collection, default)

  @hash_mapping.map(name.to_s, to: name) unless @hash_mapping.finalized?
  @json_mapping.map(name.to_s, to: name) unless @json_mapping.finalized?
  @yaml_mapping.map(name.to_s, to: name) unless @yaml_mapping.finalized?
  @toml_mapping.map(name.to_s, to: name) unless @toml_mapping.finalized?
  @csv_mapping.map(name.to_s, to: name) unless @csv_mapping.finalized?
  @xml_mapping.map_element(name.to_s, to: name) unless @xml_mapping.finalized?

  @attributes_module.class_eval(<<-RUBY, __FILE__, __LINE__ + 1)
    attr_reader :#{name}

    def #{name}=(val)
      @#{name} = #{collection} ? val : #{type}.cast(val)
    end
  RUBY
end

.csv(&block) ⇒ Object

Define CSV mapping

Examples:

class Person < Shale::Mapper
  attribute :first_name, :string
  attribute :last_name, :string
  attribute :age, :integer

  csv do
    map 'first_name', to: :first_name
    map 'last_name', to: :last_name
    map 'age', to: :age
  end
end

Parameters:

  • block (Proc) 


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# File 'lib/shale/mapper.rb', line 318

def csv(&block)
  @csv_mapping = @__csv_mapping_init.dup
  @csv_mapping.finalize!
  @csv_mapping.instance_eval(&block)
end

.hsh(&block) ⇒ Object

Define Hash mapping

Examples:

class Person < Shale::Mapper
  attribute :first_name, :string
  attribute :last_name, :string
  attribute :age, :integer

  hsh do
    map 'firstName', to: :first_name
    map 'lastName', to: :last_name
    map 'age', to: :age
  end
end

Parameters:

  • block (Proc) 


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# File 'lib/shale/mapper.rb', line 222

def hsh(&block)
  @hash_mapping = @__hash_mapping_init.dup
  @hash_mapping.finalize!
  @hash_mapping.instance_eval(&block)
end

.inherited(subclass) ⇒ 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. 



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# File 'lib/shale/mapper.rb', line 107

def inherited(subclass)
  super

  attributes_module = Module.new
  subclass.instance_variable_set('@attributes_module', attributes_module)
  subclass.include(attributes_module)

  subclass.instance_variable_set('@model', subclass)
  subclass.instance_variable_set('@attributes', @attributes.dup)

  subclass.instance_variable_set('@__hash_mapping_init', @hash_mapping.dup)
  subclass.instance_variable_set('@__json_mapping_init', @json_mapping.dup)
  subclass.instance_variable_set('@__yaml_mapping_init', @yaml_mapping.dup)
  subclass.instance_variable_set('@__toml_mapping_init', @toml_mapping.dup)
  subclass.instance_variable_set('@__csv_mapping_init', @csv_mapping.dup)
  subclass.instance_variable_set('@__xml_mapping_init', @xml_mapping.dup)

  subclass.instance_variable_set('@hash_mapping', @hash_mapping.dup)
  subclass.instance_variable_set('@json_mapping', @json_mapping.dup)
  subclass.instance_variable_set('@yaml_mapping', @yaml_mapping.dup)
  subclass.instance_variable_set('@toml_mapping', @toml_mapping.dup)
  subclass.instance_variable_set('@csv_mapping', @csv_mapping.dup)

  xml_mapping = @xml_mapping.dup
  xml_mapping.root(Utils.underscore(subclass.name || ''))

  subclass.instance_variable_set('@xml_mapping', xml_mapping.dup)
end

.json(&block) ⇒ Object

Define JSON mapping

Examples:

class Person < Shale::Mapper
  attribute :first_name, :string
  attribute :last_name, :string
  attribute :age, :integer

  json do
    map 'firstName', to: :first_name
    map 'lastName', to: :last_name
    map 'age', to: :age
  end
end

Parameters:

  • block (Proc) 


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# File 'lib/shale/mapper.rb', line 246

def json(&block)
  @json_mapping = @__json_mapping_init.dup
  @json_mapping.finalize!
  @json_mapping.instance_eval(&block)
end

.model(klass = nil) ⇒ Object 



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# File 'lib/shale/mapper.rb', line 136

def model(klass = nil)
  if klass
    @model = klass
    xml_mapping.root(Utils.underscore(@model.name))
  else
    @model
  end
end

.toml(&block) ⇒ Object

Define TOML mapping

Examples:

class Person < Shale::Mapper
  attribute :first_name, :string
  attribute :last_name, :string
  attribute :age, :integer

  toml do
    map 'first_name', to: :first_name
    map 'last_name', to: :last_name
    map 'age', to: :age
  end
end

Parameters:

  • block (Proc) 


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# File 'lib/shale/mapper.rb', line 294

def toml(&block)
  @toml_mapping = @__toml_mapping_init.dup
  @toml_mapping.finalize!
  @toml_mapping.instance_eval(&block)
end

.xml(&block) ⇒ Object

Define XML mapping

Examples:

class Person < Shale::Mapper
  attribute :first_name, :string
  attribute :last_name, :string
  attribute :age, :integer

  xml do
    root 'Person'
    map_content to: :first_name
    map_element 'LastName', to: :last_name
    map_attribute 'age', to: :age
  end
end

Parameters:

  • block (Proc) 


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# File 'lib/shale/mapper.rb', line 343

def xml(&block)
  @xml_mapping = @__xml_mapping_init.dup
  @xml_mapping.finalize!
  @xml_mapping.root('')
  @xml_mapping.instance_eval(&block)
end

.yaml(&block) ⇒ Object

Define YAML mapping

Examples:

class Person < Shale::Mapper
  attribute :first_name, :string
  attribute :last_name, :string
  attribute :age, :integer

  yaml do
    map 'first_name', to: :first_name
    map 'last_name', to: :last_name
    map 'age', to: :age
  end
end

Parameters:

  • block (Proc) 


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# File 'lib/shale/mapper.rb', line 270

def yaml(&block)
  @yaml_mapping = @__yaml_mapping_init.dup
  @yaml_mapping.finalize!
  @yaml_mapping.instance_eval(&block)
end