Class: Mongoid::Association::Referenced::HasManyThrough

Inherits:
Object
  • Object
show all
Includes:
Mongoid::Association::Relatable
Defined in:
lib/mongoid/association/referenced/has_many_through.rb,
lib/mongoid/association/referenced/has_many_through/eager.rb,
lib/mongoid/association/referenced/has_many_through/proxy.rb

Overview

Metadata class for has_many :through associations.

Defined Under Namespace

Classes: Eager, Proxy

Constant Summary collapse

ASSOCIATION_OPTIONS =

The options available for this type of association, in addition to the common ones.

Returns:

  • (Array<Symbol>) —

    The extra valid options.

i[order source through].freeze
VALID_OPTIONS =

The complete list of valid options for this association, including the shared ones.

Returns:

  • (Array<Symbol>) —

    The valid options.

(ASSOCIATION_OPTIONS + SHARED_OPTIONS).freeze

Constants included from Mongoid::Association::Relatable

Mongoid::Association::Relatable::PRIMARY_KEY_DEFAULT, Mongoid::Association::Relatable::SHARED_OPTIONS

Instance Attribute Summary

Attributes included from Mongoid::Association::Relatable

#name, #options, #owner_class, #parent_inclusions

Instance Method Summary collapse

Methods included from Mongoid::Association::Relatable

#==, #bindable?, #counter_cache_column_name, #create_relation, #destructive?, #extension, #foreign_key_check, #foreign_key_setter, #get_callbacks, #in_to?, #initialize, #inverse, #inverse_association, #inverse_class, #inverse_class_name, #inverse_setter, #inverse_type, #inverse_type_setter, #inverses, #key, #many?, #many_to_many?, #one?, #path, #relation_class, #relation_class_name, #setter, #try_relation_class, #type_setter, #validate?

Methods included from Options

#as, #autobuilding?, #autosave, #cascading_callbacks?, #counter_cached?, #cyclic?, #dependent, #fallback, #fallback?, #forced_nil_inverse?, #indexed?, #inverse_of, #order, #polymorphic?, #primary_key, #store_as, #touch_field, #touchable?, #type

Methods included from Constrainable

#convert_to_foreign_key

Instance Method Details

#criteria(base) ⇒ Mongoid::Criteria

Return a Criteria scoped to the target documents reachable from base via the through association. Performs two queries: one against the intermediate collection, one against the source collection.

Parameters:

  • base (Document) —

    The owner document.

Returns:



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# File 'lib/mongoid/association/referenced/has_many_through.rb', line 117

def criteria(base)
  through_crit = through_association.criteria(base)

  crit = if source_association.stores_foreign_key?
           # FK is on the intermediate (e.g. appointment.patient_id -> belongs_to :patient)
           target_pk = source_association.primary_key # '_id' on Patient
           source_fk = source_association.foreign_key # 'patient_id' on Appointment
           source_association.klass.where(
             target_pk => { '$in' => key_values(through_crit, source_fk) }
           )
         else
           # FK is on the source (e.g. reader.book_id -> has_many :readers on Book)
           source_pk = source_association.primary_key # '_id' on intermediate (Book)
           source_fk = source_association.foreign_key # 'book_id' on Reader
           source_association.klass.where(
             source_fk => { '$in' => key_values(through_crit, source_pk) }
           )
         end
  order ? crit.order_by(order) : crit
end

#embedded? ⇒ false

Is this association embedded?

Returns:

  • (false) 


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# File 'lib/mongoid/association/referenced/has_many_through.rb', line 43

def embedded?
  false
end

#relation ⇒ Class

The proxy class for this association type.

Returns:

  • (Class) 


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# File 'lib/mongoid/association/referenced/has_many_through.rb', line 50

def relation
  Proxy
end

#relation_complements ⇒ Array

The list of association complements.

Returns:

  • (Array) 


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# File 'lib/mongoid/association/referenced/has_many_through.rb', line 28

def relation_complements
  [].freeze
end

#setup! ⇒ self

Setup instance methods on the owner class.

Returns:

  • (self) 


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# File 'lib/mongoid/association/referenced/has_many_through.rb', line 35

def setup!
  setup_instance_methods!
  self
end

#source_association ⇒ Mongoid::Association::Relatable

The source association metadata on the intermediate class. Resolved lazily to allow forward references.

Returns:



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# File 'lib/mongoid/association/referenced/has_many_through.rb', line 89

def source_association
  @source_association ||= begin
    source_name = (@options[:source] || name.to_s.singularize).to_s
    assoc = through_association.klass.relations[source_name] ||
            raise(
              Errors::InvalidRelationOption.new(
                @owner_class, name, :source, source_name
              )
            )
    if assoc.is_a?(Referenced::HasAndBelongsToMany)
      raise(
        Errors::InvalidRelationOption.new(
          @owner_class, name, :source,
          'has_and_belongs_to_many is not supported as a :through source'
        )
      )
    end
    assoc
  end
end

#stores_foreign_key? ⇒ false

Through associations never store a foreign key on the owner document.

Returns:

  • (false) 


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# File 'lib/mongoid/association/referenced/has_many_through.rb', line 57

def stores_foreign_key?
  false
end

#through_association ⇒ Mongoid::Association::Relatable

The intermediate association metadata on the owner class. Resolved lazily to allow forward references.

Returns:



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# File 'lib/mongoid/association/referenced/has_many_through.rb', line 65

def through_association
  @through_association ||= begin
    assoc = @owner_class.relations[@options[:through].to_s] ||
            raise(
              Errors::InvalidRelationOption.new(
                @owner_class, name, :through, @options[:through]
              )
            )
    if assoc.embedded?
      raise(
        Errors::InvalidRelationOption.new(
          @owner_class, name, :through,
          'through association must be a referenced association, not embedded'
        )
      )
    end
    assoc
  end
end

#validation_default ⇒ false

The default for validating the association object.

Returns:

  • (false) 


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# File 'lib/mongoid/association/referenced/has_many_through.rb', line 141

def validation_default
  false
end