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Class: ActiveRecord::Associations::JoinDependency::JoinPart

Do not use. This class is for internal use only.
Relationships & Source Files
Extension / Inclusion / Inheritance Descendants
Subclasses:
JoinAssociation, JoinBase
Super Chains via Extension / Inclusion / Inheritance
Instance Chain:
self, ::Enumerable, ::ActiveSupport::EnumerableCoreExt::Constants
Inherits: Object
Defined in: activerecord/lib/active_record/associations/join_dependency/join_part.rb

Overview

A JoinPart represents a part of a ::ActiveRecord::Associations::JoinDependency. It is inherited by JoinBase and JoinAssociation. A JoinBase represents the Active Record which everything else is being joined onto. A JoinAssociation represents an association which is joining to the base. A JoinAssociation may result in more than one actual join operations (for example a has_and_belongs_to_many JoinAssociation would result in two; one for the join table and one for the target table).

Class Method Summary

Instance Attribute Summary

::Enumerable - Included

#many?

Returns true if the enumerable has more than 1 element.

Instance Method Summary

::Enumerable - Included

#compact_blank

Returns a new ::Array without the blank items.
#exclude?

The negative of the Enumerable#include?.
#excluding

Returns a copy of the enumerable excluding the specified elements.
#in_order_of

Returns a new ::Array where the order has been set to that provided in the series, based on the key of the objects in the original enumerable.
#including

Returns a new array that includes the passed elements.
#index_by

Convert an enumerable to a hash, using the block result as the key and the element as the value.
#index_with

Convert an enumerable to a hash, using the element as the key and the block result as the value.
#maximum

Calculates the maximum from the extracted elements.
#minimum

Calculates the minimum from the extracted elements.
#pick

Extract the given key from the first element in the enumerable.
#pluck

Extract the given key from each element in the enumerable.
#sole

Returns the sole item in the enumerable.
#without

Alias for Enumerable#excluding.
#as_json

::ActiveSupport::EnumerableCoreExt::Constants - Included

#const_missing

Constructor Details

.new(base_klass, children) ⇒ JoinPart

[ GitHub ] 

  


# File 'activerecord/lib/active_record/associations/join_dependency/join_part.rb', line 22



def initialize(base_klass, children)
  @base_klass = base_klass
  @children = children
end


  







Instance Attribute Details



  

    #attribute_types   (readonly)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/associations/join_dependency/join_part.rb', line 20



delegate :table_name, :column_names, :primary_key, :attribute_types, to: :base_klass


  








  

    #base_klass   (readonly)
  



  

    

The Active Record class which this join part is associated ‘about’; for a JoinBase this is the actual base model, for a JoinAssociation this is the target model of the association.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/associations/join_dependency/join_part.rb', line 18



attr_reader :base_klass, :children


  








  

    #children   (readonly)
  



  

    

The Active Record class which this join part is associated ‘about’; for a JoinBase this is the actual base model, for a JoinAssociation this is the target model of the association.


  



  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/associations/join_dependency/join_part.rb', line 18



attr_reader :base_klass, :children


  








  

    #column_names   (readonly)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/associations/join_dependency/join_part.rb', line 20



delegate :table_name, :column_names, :primary_key, :attribute_types, to: :base_klass


  








  

    #primary_key   (readonly)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/associations/join_dependency/join_part.rb', line 20



delegate :table_name, :column_names, :primary_key, :attribute_types, to: :base_klass


  








  

    #table_name   (readonly)
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/associations/join_dependency/join_part.rb', line 20



delegate :table_name, :column_names, :primary_key, :attribute_types, to: :base_klass


  







Instance Method Details



  

    #each {|_self| ... } 
  



  

    
  





  
Yields:


    
  
  • 
    (_self)
  
    • 



Yield Parameters:


    
  
  • 
    _self
    (JoinPart)
—    
    

    the object that the method was called on
    

    
  
    • 





  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/associations/join_dependency/join_part.rb', line 31



def each(&block)
  yield self
  children.each { |child| child.each(&block) }
end


  








  

    #each_children(&block)  
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/associations/join_dependency/join_part.rb', line 36



def each_children(&block)
  children.each do |child|
    yield self, child
    child.each_children(&block)
  end
end


  








  

    #extract_record(row, column_names_with_alias)  
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/associations/join_dependency/join_part.rb', line 48



def extract_record(row, column_names_with_alias)
  # This code is performance critical as it is called per row.
  # see: https://github.com/rails/rails/pull/12185
  hash = {}

  index = 0
  length = column_names_with_alias.length

  while index < length
    column = column_names_with_alias[index]
    hash[column.name] = row[column.alias]
    index += 1
  end

  hash
end


  








  

    #instantiate(row, aliases, column_types = {}, &block)  
  

  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/associations/join_dependency/join_part.rb', line 65



def instantiate(row, aliases, column_types = {}, &block)
  base_klass.instantiate(extract_record(row, aliases), column_types, &block)
end


  








  

    #match?(other)  ⇒ Boolean 
  



  

    
  





  


  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/associations/join_dependency/join_part.rb', line 27



def match?(other)
  self.class == other.class
end


  








  

    #table  
  



  

    

An ::Arel::Table for the active_record


  





  
Raises:


    
  
  • 
    (NotImplementedError)
  
    • 





  [ GitHub ]


  

  


# File 'activerecord/lib/active_record/associations/join_dependency/join_part.rb', line 44



def table
  raise NotImplementedError
end