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Class: Mongoid::Association::EagerLoad::PolymorphicTargets Private

Relationships & Source Files
Extension / Inclusion / Inheritance Descendants
Subclasses:
OtherDatabaseTargets, SameDatabaseTargets
Inherits: Object
Defined in: lib/mongoid/association/eager_load/polymorphic_targets.rb

Overview

The targets of a polymorphic belongs_to, indexed as { type => { primary_key => document } }. Each subclass reaches the types that live in one place (the root's database or elsewhere); .for resolves the whole set, routing each type to the subclass that can reach it.

Class Method Summary

Instance Method Summary

Constructor Details

.new(association, keys_by_type) ⇒ PolymorphicTargets

[ GitHub ] 

  


# File 'lib/mongoid/association/eager_load/polymorphic_targets.rb', line 43



def initialize(association, keys_by_type)
  @association = association
  @keys_by_type = keys_by_type
end


  







Class Method Details



  

    .for(association, keys_by_type, root_class)  ⇒ Hash 
  



  

    
Resolve every polymorphic target for the foreign keys grouped by type.
The types whose documents share the root's database are fetched together
in one $facet; those living elsewhere are read through their own models.

  





  
Parameters:


    
  
  • 
    association
    (Mongoid::Association::Relatable)
—    
    The polymorphic inclusion.
    
  
    • 
  
  • 
    keys_by_type
    (Hash)
—    
    The foreign keys grouped by type.
    
  
    • 
  
  • 
    root_class
    (Class)
—    
    The class being queried.
    
  
    • 



Returns:


    
  
  • 
    (Hash)
—    
    The targets, as { type => { primary_key => document } }.
    
  
    • 





  [ GitHub ]


  

  


# File 'lib/mongoid/association/eager_load/polymorphic_targets.rb', line 23



def for(association, keys_by_type, root_class)
  here, elsewhere = keys_by_type.partition do |type, _keys|
    in_root_database?(association, type, root_class)
  end
  same_database = SameDatabaseTargets.new(association, here.to_h, root_class)
  other_databases = OtherDatabaseTargets.new(association, elsewhere.to_h)
  same_database.fetch.merge(other_databases.fetch)
end


  








  

    .in_root_database?(association, type, root_class)  ⇒ Boolean  (private)
  



  

    
Whether the type's model shares the root's database (and client): exactly
what a $lookup from the root collection can reach.

  





  


  [ GitHub ]


  

  


# File 'lib/mongoid/association/eager_load/polymorphic_targets.rb', line 36



def in_root_database?(association, type, root_class)
  model = association.resolver.model_for(type)
  model.client_name == root_class.client_name &&
    model.database_name == root_class.database_name
end


  







Instance Method Details



  

    #fetch  ⇒ Hash 
  



  

    
  





  
Returns:


    
  
  • 
    (Hash)
—    
    The targets, as { type => { primary_key => document } }.
    
  
    • 



Raises:


    
  
  • 
    (NotImplementedError)
  
    • 





  [ GitHub ]


  

  


# File 'lib/mongoid/association/eager_load/polymorphic_targets.rb', line 49



def fetch
  raise NotImplementedError
end


  








  

    #indexed(documents, model)   (private)
  



  

    
The raw documents instantiated and indexed by their primary key.

  





  


  [ GitHub ]


  

  


# File 'lib/mongoid/association/eager_load/polymorphic_targets.rb', line 64



def indexed(documents, model)
  documents.map { |document| Factory.from_db(model, document) }
           .index_by { |document| document.send(primary_key) }
end


  








  

    #model_for(type)   (private)
  

  [ GitHub ]


  

  


# File 'lib/mongoid/association/eager_load/polymorphic_targets.rb', line 59



def model_for(type)
  @association.resolver.model_for(type)
end


  








  

    #primary_key   (private)
  

  [ GitHub ]


  

  


# File 'lib/mongoid/association/eager_load/polymorphic_targets.rb', line 55



def primary_key
  @association.primary_key
end