destroyed_by_association=(reflection) Instance Public methods Records the association that is being destroyed and destroying this record in the process.

destroyed_by_association() Instance Public methods Returns the association for the parent being destroyed. Used to avoid updating the counter cache unnecessarily.

changed_for_autosave?() Instance Public methods Returns whether or not this record has been changed in any way (including whether any of its nested autosave associations are likewise changed)

respond_to?(name, include_private = false) Instance Public methods 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 define 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 pers

has_attribute?(attr_name) Instance Public methods Returns true if the given attribute is in the attributes hash, otherwise false. class Person < ActiveRecord::Base end person = Person.new person.has_attribute?(:name) # => true person.has_attribute?('age') # => true person.has_attribute?(:nothing) # => false

column_for_attribute(name) Instance Public methods Returns the column object for the named attribute. Returns nil if the named attribute not exists. class Person < ActiveRecord::Base end person = Person.new person.column_for_attribute(:name) # the result depends on the ConnectionAdapter # => #<ActiveRecord::ConnectionAdapters::SQLite3Column:0x007ff4ab083980 @name="name", @sql_type="varchar(255)", @null=true, ...> person.column_for_attribute(:nothing) # => nil

attributes() Instance Public methods Returns a hash of all the attributes with their names as keys and the values of the attributes as values. class Person < ActiveRecord::Base end person = Person.create(name: 'Francesco', age: 22) person.attributes # => {"id"=>3, "created_at"=>Sun, 21 Oct 2012 04:53:04, "updated_at"=>Sun, 21 Oct 2012 04:53:04, "name"=>"Francesco", "age"=>22}

attribute_present?(attribute) Instance Public methods Returns true if the specified attribute has been set by the user or by a database load and is neither nil nor empty? (the latter only applies to objects that respond to empty?, most notably Strings). Otherwise, false. Note that it always returns true with boolean attributes. class Task < ActiveRecord::Base end person = Task.new(title: '', is_done: false) person.attribute_present?(:title) # => false person.attribute_pres

attribute_names() Instance Public methods Returns an array of names for the attributes available on this object. class Person < ActiveRecord::Base end person = Person.new person.attribute_names # => ["id", "created_at", "updated_at", "name", "age"]

attribute_for_inspect(attr_name) Instance Public methods Returns an #inspect-like string for the value of the attribute attr_name. String attributes are truncated upto 50 characters, Date and Time attributes are returned in the :db format, Array attributes are truncated upto 10 values. Other attributes return the value of #inspect without modification. person = Person.create!(name: 'David Heinemeier Hansson ' * 3) person.attribute_for_inspect(:name) # => "\"David Heinemeier Han