Class: ActiveRecord::Associations::JoinDependency::JoinAssociation

Inherits:
JoinPart
  • Object
show all
Defined in:
lib/active_record/associations/join_dependency/join_association.rb

Overview

:nodoc:

Instance Attribute Summary collapse

Attributes inherited from JoinPart

#base_klass, #children

Instance Method Summary collapse

Methods inherited from JoinPart

#each, #extract_record, #instantiate

Constructor Details

#initialize(reflection, children, alias_tracker) ⇒ JoinAssociation

Returns a new instance of JoinAssociation.



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# File 'lib/active_record/associations/join_dependency/join_association.rb', line 14

def initialize(reflection, children, alias_tracker)
  super(reflection.klass, children)

  @alias_tracker = alias_tracker
  @reflection    = reflection
  @tables        = nil
end

Instance Attribute Details

#reflection ⇒ Object (readonly)

The reflection of the association represented



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# File 'lib/active_record/associations/join_dependency/join_association.rb', line 10

def reflection
  @reflection
end

#tables ⇒ Object

Returns the value of attribute tables.



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# File 'lib/active_record/associations/join_dependency/join_association.rb', line 12

def tables
  @tables
end

Instance Method Details

#join_constraints(foreign_table, foreign_klass, join_type, tables, chain) ⇒ Object 



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

def join_constraints(foreign_table, foreign_klass, join_type, tables, chain)
  joins         = []
  tables        = tables.reverse

  # The chain starts with the target table, but we want to end with it here (makes
  # more sense in this context), so we reverse
  chain.reverse_each do |reflection|
    table = tables.shift
    klass = reflection.klass

    constraint = reflection.build_join_constraint(table, foreign_table)

    joins << table.create_join(table, table.create_on(constraint), join_type)

    join_scope = reflection.join_scope(table, foreign_klass)
    arel = join_scope.arel(alias_tracker.aliases)

    if arel.constraints.any?
      joins.concat arel.join_sources
      right = joins.last.right
      right.expr = right.expr.and(arel.constraints)
    end

    # The current table in this iteration becomes the foreign table in the next
    foreign_table, foreign_klass = table, klass
  end

  joins
end

#match?(other) ⇒ Boolean

Returns:

  • (Boolean) 


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

def match?(other)
  return true if self == other
  super && reflection == other.reflection
end

#table ⇒ Object 



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# File 'lib/active_record/associations/join_dependency/join_association.rb', line 57

def table
  tables.first
end