Class: ActiveRecord::Associations::Preloader::Association

Inherits:

Object

• Object
• ActiveRecord::Associations::Preloader::Association

show all

Defined in:

activerecord/lib/active_record/associations/preloader/association.rb

Overview

Instance Attribute Summary (collapse)

• - (Object) klass readonly

  Returns the value of attribute klass.

• - (Object) model readonly

  Returns the value of attribute model.

• - (Object) owners readonly

  Returns the value of attribute owners.

• - (Object) preload_options readonly

  Returns the value of attribute preload_options.

• - (Object) reflection readonly

  Returns the value of attribute reflection.

Instance Method Summary (collapse)

• - (Object) association_key

  This is overridden by HABTM as the condition should be on the foreign_key column in the join table.

• - (Object) association_key_name

  The name of the key on the associated records.

• - (Association) initialize(klass, owners, reflection, preload_options) constructor

  A new instance of Association.

• - (Object) options
• - (Object) owner_key_name

  The name of the key on the model which declares the association.

• - (Object) owners_by_key

  We're converting to a string here because postgres will return the aliased association key in a habtm as a string (for whatever reason).

• - (Object) preload
• - (Object) records_for(ids)
• - (Object) run
• - (Object) scoped
• - (Object) table

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# File 'activerecord/lib/active_record/associations/preloader/association.rb', line 7

def initialize(klass, owners, reflection, preload_options)
  @klass           = klass
  @owners          = owners
  @reflection      = reflection
  @preload_options = preload_options || {}
  @model           = owners.first && owners.first.class
  @scoped          = nil
  @owners_by_key   = nil
end

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# File 'activerecord/lib/active_record/associations/preloader/association.rb', line 5

def klass
  @klass
end

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# File 'activerecord/lib/active_record/associations/preloader/association.rb', line 5

def model
  @model
end

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# File 'activerecord/lib/active_record/associations/preloader/association.rb', line 5

def owners
  @owners
end

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# File 'activerecord/lib/active_record/associations/preloader/association.rb', line 5

def preload_options
  @preload_options
end

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# File 'activerecord/lib/active_record/associations/preloader/association.rb', line 5

def reflection
  @reflection
end

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# File 'activerecord/lib/active_record/associations/preloader/association.rb', line 46

def association_key
  table[association_key_name]
end

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# File 'activerecord/lib/active_record/associations/preloader/association.rb', line 40

def association_key_name
  raise NotImplementedError
end

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# File 'activerecord/lib/active_record/associations/preloader/association.rb', line 64

def options
  reflection.options
end

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# File 'activerecord/lib/active_record/associations/preloader/association.rb', line 51

def owner_key_name
  raise NotImplementedError
end

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# File 'activerecord/lib/active_record/associations/preloader/association.rb', line 57

def owners_by_key
  @owners_by_key ||= owners.group_by do |owner|
    key = owner[owner_key_name]
    key && key.to_s
  end
end

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# File 'activerecord/lib/active_record/associations/preloader/association.rb', line 23

def preload
  raise NotImplementedError
end

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# File 'activerecord/lib/active_record/associations/preloader/association.rb', line 31

def records_for(ids)
  scoped.where(association_key.in(ids))
end

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# File 'activerecord/lib/active_record/associations/preloader/association.rb', line 17

def run
  unless owners.first.association(reflection.name).loaded?
    preload
  end
end

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# File 'activerecord/lib/active_record/associations/preloader/association.rb', line 27

def scoped
  @scoped ||= build_scope
end

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# File 'activerecord/lib/active_record/associations/preloader/association.rb', line 35

def table
  klass.arel_table
end