Class: Arerd::Association

Inherits:
Object
  • Object
show all
Includes:
Comparable
Defined in:
lib/arerd/association.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(left_model:, left_key:, left_association_name:, right_model:, right_key:, right_association_name:, left_side_multiplicity:, right_side_multiplicity:) ⇒ Association

Returns a new instance of Association.



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# File 'lib/arerd/association.rb', line 11

def initialize(
  left_model:,
  left_key:,
  left_association_name:,
  right_model:,
  right_key:,
  right_association_name:,
  left_side_multiplicity:,
  right_side_multiplicity:
)
  @left_model = left_model
  @left_key = left_key
  @left_association_name = left_association_name
  @right_model = right_model
  @right_key = right_key
  @right_association_name = right_association_name
  @left_side_multiplicity = left_side_multiplicity
  @right_side_multiplicity = right_side_multiplicity
end

Instance Attribute Details

#left_association_name ⇒ Object (readonly)

Returns the value of attribute left_association_name.



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# File 'lib/arerd/association.rb', line 7

def left_association_name
  @left_association_name
end

#left_key ⇒ Object (readonly)

Returns the value of attribute left_key.



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# File 'lib/arerd/association.rb', line 7

def left_key
  @left_key
end

#left_model ⇒ Object (readonly)

Returns the value of attribute left_model.



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# File 'lib/arerd/association.rb', line 7

def left_model
  @left_model
end

#left_side_multiplicity ⇒ Object (readonly)

Returns the value of attribute left_side_multiplicity.



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# File 'lib/arerd/association.rb', line 7

def left_side_multiplicity
  @left_side_multiplicity
end

#right_association_name ⇒ Object (readonly)

Returns the value of attribute right_association_name.



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# File 'lib/arerd/association.rb', line 7

def right_association_name
  @right_association_name
end

#right_key ⇒ Object (readonly)

Returns the value of attribute right_key.



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# File 'lib/arerd/association.rb', line 7

def right_key
  @right_key
end

#right_model ⇒ Object (readonly)

Returns the value of attribute right_model.



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# File 'lib/arerd/association.rb', line 7

def right_model
  @right_model
end

#right_side_multiplicity ⇒ Object (readonly)

Returns the value of attribute right_side_multiplicity.



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# File 'lib/arerd/association.rb', line 7

def right_side_multiplicity
  @right_side_multiplicity
end

Class Method Details

.build(association) ⇒ Object 



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# File 'lib/arerd/association.rb', line 38

def self.build(association)
  case association.macro
  when :has_many
    return if association.options[:through]

    if association.inverse_of.nil?
      warn "Association #{association.name} has no inverse association. Skipping association."

      return
    end

    new(
      left_model: association.active_record,
      left_key: association.active_record_primary_key,
      left_association_name: association.name,
      right_model: association.class_name.constantize,
      right_key: association.foreign_key,
      right_association_name: association.inverse_of.name,
      left_side_multiplicity: association.inverse_of.options[:optional] ? :optional_one : :one,
      right_side_multiplicity: :optional_many
    )
  when :has_one
    return if association.options[:through]

    if association.inverse_of.nil?
      warn "Association #{association.name} has no inverse association. Skipping association."

      return
    end

    new(
      left_model: association.active_record,
      left_key: association.active_record_primary_key,
      left_association_name: association.name,
      right_model: association.class_name.constantize,
      right_key: association.foreign_key,
      right_association_name: association.inverse_of.name,
      left_side_multiplicity: association.inverse_of.options[:optional] ? :optional_one : :one,
      right_side_multiplicity: :optional_one
    )
  when :has_and_belongs_to_many
    if association.inverse_of.nil?
      warn "Association #{association.name} has no inverse association. Skipping association."

      return
    end

    return if association.active_record.name > association.class_name # Avoid duplicate associations

    new(
      left_model: association.active_record,
      left_key: association.active_record_primary_key,
      left_association_name: association.name,
      right_model: association.class_name.constantize,
      right_key: association.foreign_key,
      right_association_name: association.inverse_of.name,
      left_side_multiplicity: :optional_many,
      right_side_multiplicity: :optional_many
    )
  when :belongs_to
    if association.options[:polymorphic]
      warn "Polymorphic associations are not supported yet. Skipping association #{association.name}."

      return
    end

    if association.inverse_of.nil?
      warn "Association #{association.name} has no inverse association."
    end
  else
    warn "Unknown association type: #{association.macro} for #{association.name} in #{left_model.name}"
  end
end

.build_associations_from_models(models) ⇒ Object 



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# File 'lib/arerd/association.rb', line 112

def self.build_associations_from_models(models)
  models.flat_map(&:reflect_on_all_associations).map { |association|
    build(association)
  }.compact
end

Instance Method Details

#<=>(other) ⇒ Object 



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# File 'lib/arerd/association.rb', line 31

def <=>(other)
  return nil unless other.is_a?(Association)

  [left_model.name, right_model.name, left_association_name.to_s, right_association_name.to_s] <=>
    [other.left_model.name, other.right_model.name, other.left_association_name.to_s, other.right_association_name.to_s]
end