instance method `respond_to?`

Ruby on Rails 5.2.8.1

Since v4.0.13

Available in: v4.0.13 v4.1.16 v4.2.9 v5.2.8.1 v6.0.6 v6.1.7.10 v7.0.10 v7.1.6 v7.2.3 v8.0.4 v8.1.2

Compare with:

respond_to?(name, include_private = false)

A Person object with a name attribute can ask person.respond_to?(:name), person.respond_to?(:name=), and person.respond_to?(:name?) which will all return true. It also defines the attribute methods if they have not been generated.

class Person < ActiveRecord::Base
end

person = Person.new
person.respond_to?(:name)    # => true
person.respond_to?(:name=)   # => true
person.respond_to?(:name?)   # => true
person.respond_to?('age')    # => true
person.respond_to?('age=')   # => true
person.respond_to?('age?')   # => true
person.respond_to?(:nothing) # => false

Parameters

name req
include_private opt = false

Source

# File activerecord/lib/active_record/attribute_methods.rb, line 270
    def respond_to?(name, include_private = false)
      return false unless super

      case name
      when :to_partial_path
        name = "to_partial_path".freeze
      when :to_model
        name = "to_model".freeze
      else
        name = name.to_s
      end

      # If the result is true then check for the select case.
      # For queries selecting a subset of columns, return false for unselected columns.
      # We check defined?(@attributes) not to issue warnings if called on objects that
      # have been allocated but not yet initialized.
      if defined?(@attributes) && self.class.column_names.include?(name)
        return has_attribute?(name)
      end

      true
    end

Defined in activerecord/lib/active_record/attribute_methods.rb line 270 · View on GitHub · Improve this page · Find usages on GitHub

Defined in ActiveRecord::AttributeMethods

Signature

Parameters