Module: ContentfulModel::Associations::HasOne::ClassMethods

Defined in:
lib/contentful_model/associations/has_one.rb

Overview

Class method

Instance Method Summary collapse

Instance Method Details

#has_one(association_name, options = {}) ⇒ Object

has_one defines a method on the parent which wraps around the superclass’s implementation. In most cases this will end up at ContentfulModel::Base#method_missing and look at the fields on a content object. We wrap around it like this so we can specify a class_name option to call a different method from the association name.

class Foo

has_one :special_bar, class_name: "Bar"

end

rubocop:disable Style/PredicateName

Parameters:

  • association_name (Symbol) —

    the name of the association. In this case Foo.special_bar.

  • options (Hash) (defaults to: {}) —

    a hash, the only key of which is important is class_name.



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# File 'lib/contentful_model/associations/has_one.rb', line 23

def has_one(association_name, options = {})
  default_options = {
    class_name: association_name.to_s.classify,
    inverse_of: to_s.underscore.to_sym
  }
  options = default_options.merge(options)

  include_discovered(options[:class_name])

  # Define a method which matches the association name
  define_method association_name do
    begin
      # Start by calling the association name as a method on the superclass.
      # this will end up in ContentfulModel::Base#method_missing and return the value from Contentful.
      # We set the singular of the association name on this object to allow easy recursing.
      super().tap do |child|
        child.send(:"#{options[:inverse_of]}=", self) if child.respond_to?(:"#{options[:inverse_of]}=")
      end
    rescue NoMethodError
      # If method_missing returns an error, the field doesn't exist. If a class is specified, try that.
      possible_field_name = options[:class_name].underscore.to_sym
      return send(possible_field_name) if possible_field_name != association_name && respond_to?(possible_field_name)
      nil
    end
  end
end