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Module: Mongoid::FieldReadable Private

Relationships & Source Files
Extension / Inclusion / Inheritance Descendants
Included In:
Association::Referenced::HasMany::Enumerable, Contextual::Aggregable::Memory, Contextual::Memory
Defined in: lib/mongoid/field_readable.rb

Overview

Reads the value of a field name from a document without dispatching the name as an arbitrary method.

Field names may come from application input, where a name like destroy or attributes would delete the document or disclose its contents. Declared field and association names are validated when they are declared (see ::Mongoid.destructive_fields), so a name that resolves to one of them is safe to send to a document. Any other name is read from the attributes hash, which is what the database-backed query contexts do.

Instance Method Summary

Instance Method Details

#read_field_value(document, name) ⇒ Object | nil (private)

Read the value of the given field name from the given document.

Parameters:

  • document (Document) —

    The document to read from.

  • name (String | Symbol) —

    The name of the field.

Returns:

  • (Object | nil) —

    The value of the field, or nil when the name is neither a declared field nor present in the attributes.

[ GitHub ] 

  


# File 'lib/mongoid/field_readable.rb', line 25



def read_field_value(document, name)
  name = name.to_s
  # A blank name cannot name a field. Return nil, which is what reading
  # one has always done.
  return nil if name.blank?

  if (meth = readable_method_for(document.class, name))
    document.public_send(meth)
  else
    document.attributes[document.class.database_field_name(name)]
  end
end


  








  

    #readable_method_for(klass, name)  ⇒ String | nil  (private)
  



  

    
Resolve the given name to a method that is declared by the given class,
and therefore safe to send to one of its instances.

  





  
Parameters:


    
  
  • 
    klass
    (Class)
—    
    The document class.
    
  
    • 
  
  • 
    name
    (String)
—    
    The name of the field.
    
  
    • 



Returns:


    
  
  • 
    (String | nil)
—    
    The method to send, or nil when the name is
not declared by the class.
    
  
    • 





  [ GitHub ]


  

  


# File 'lib/mongoid/field_readable.rb', line 46



def readable_method_for(klass, name)
  # Fields, associations, and field aliases each define a reader of their
  # own name. Note that associations must be resolved before aliases: a
  # belongs_to aliases its own name to its foreign key, and reading
  # `band` must give the document, not the id.
  return name if klass.relations.key?(name) ||
                 klass.fields.key?(name) ||
                 klass.aliased_fields.key?(name)

  # An association may also be named by its `store_as`, which has no
  # reader of its own, or by its ids accessor, which does.
  if (assoc = klass.relations[klass.aliased_associations[name]])
    return (assoc.store_as == name) ? assoc.name.to_s : name
  end

  # Localized fields also get a _translations reader, which does not
  # appear in the fields hash.
  base = name.delete_suffix(Fields::TRANSLATIONS_SFX)
  return nil if base == name

  name if klass.fields[klass.database_field_name(base)]&.localized?
end