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Class: Mongoid::Attributes::Projector Private

Do not use. This class is for internal use only.
Relationships & Source Files
Inherits: Object
Defined in: lib/mongoid/attributes/projector.rb

Overview

This module defines projection helpers.

Projection rules are rather non-trivial. See www.mongodb.com/docs/manual/reference/method/db.collection.find/#find-projection for server documentation. 4.4 server (and presumably all older ones) requires that a projection for content fields is either exclusionary or inclusionary, i.e. one cannot mix exclusions and inclusions in the same query. However, _id can be excluded in a projection that includes content fields. ::Integer projection values other than 0 and 1 aren’t officially documented as of this writing; see DOCSP-15266. 4.4 server also allows nested hash projection specification in addition to dot notation, which I assume ::Mongoid doesn’t handle yet.

Class Method Summary

Instance Attribute Summary

Instance Method Summary

Instance Attribute Details

#content_inclusionary? ⇒ Boolean (readonly, private)

Determines whether the projection for content fields is inclusionary.

An empty projection is inclusionary.

[ GitHub ] 

  


# File 'lib/mongoid/attributes/projector.rb', line 96



def content_inclusionary?
  if content_projection.empty?
    return value_inclusionary?(id_projection_value)
  end

  value_inclusionary?(content_projection.values.first)
end


  








  

    #content_projection   (readonly)
  

  [ GitHub ]


  

  


# File 'lib/mongoid/attributes/projector.rb', line 36



attr_reader :content_projection


  








  

    #id_projection_value   (readonly)
  

  [ GitHub ]


  

  


# File 'lib/mongoid/attributes/projector.rb', line 35



attr_reader :id_projection_value


  







Instance Method Details



  

    #attribute_or_path_allowed?(name)  ⇒ true | false 
  



  

    

Determine if the specified attribute, or a dot notation path, is allowed by the configured projection, if any.



If there is no configured projection, returns true.


  





  
Parameters:


    
  
  • 
    name
    (String)
—    
    

    The name of the attribute or a dot notation path.
    

    
  
    • 



Returns:


    
  
  • 
    (true | false)
—    
    

    Whether the attribute is allowed by projection.
    

    
  
    • 





  [ GitHub ]


  

  


# File 'lib/mongoid/attributes/projector.rb', line 48



def attribute_or_path_allowed?(name)
  # Special handling for _id.
  if name == '_id'
    result = unless id_projection_value.nil?
      value_inclusionary?(id_projection_value)
    else
      true
    end
    return result
  end

  if content_projection.nil?
    # No projection (as opposed to an empty projection).
    # All attributes are allowed.
    return true
  end

  # Find an item which matches or is a parent of the requested name/path.
  # This handles the case when, for example, the projection was
  # {foo: true} and we want to know if foo.bar is allowed.
  item, value = content_projection.detect do |path, value|
    (name + '.').start_with?(path + '.')
  end
  if item
    return value_inclusionary?(value)
  end

  if content_inclusionary?
    # Find an item which would be a strict child of the requested name/path.
    # This handles the case when, for example, the projection was
    # {"foo.bar" => true} and we want to know if foo is allowed.
    # (It is as a container of bars.)
    item, value = content_projection.detect do |path, value|
      (path + '.').start_with?(name + '.')
    end
    if item
      return true
    end
  end

  !content_inclusionary?
end


  








  

    #value_inclusionary?(value)  ⇒ Boolean  (private)
  



  

    
  





  


  [ GitHub ]


  

  


# File 'lib/mongoid/attributes/projector.rb', line 104



def value_inclusionary?(value)
  case value
  when Integer
    value >= 1
  when true
    true
  when false
    false
  else
    # The various expressions that are permitted as projection arguments
    # imply an inclusionary projection.
    true
  end
end