module ActiveRecord::AttributeMethods::Dirty
Active Record Attribute Methods Dirty¶ ↑
Provides a way to track changes in your Active Record models. It adds all methods from ActiveModel::Dirty and adds database-specific methods.
A newly created Person
object is unchanged:
class Person < ActiveRecord::Base end person = Person.create(name: "Allison") person.changed? # => false
Change the name:
person.name = 'Alice' person.name_in_database # => "Allison" person.will_save_change_to_name? # => true person.name_change_to_be_saved # => ["Allison", "Alice"] person.changes_to_save # => {"name"=>["Allison", "Alice"]}
Save the changes:
person.save person.name_in_database # => "Alice" person.saved_change_to_name? # => true person.saved_change_to_name # => ["Allison", "Alice"] person.name_before_last_save # => "Allison"
Similar to ActiveModel::Dirty, methods can be invoked as saved_change_to_name?
or by passing an argument to the generic method saved_change_to_attribute?("name")
.
Public Instance Methods
Source
# File lib/active_record/attribute_methods/dirty.rb, line 108 def attribute_before_last_save(attr_name) mutations_before_last_save.original_value(attr_name.to_s) end
Returns the original value of an attribute before the last save.
This method is useful in after callbacks to get the original value of an attribute before the save that triggered the callbacks to run. It can be invoked as name_before_last_save
instead of attribute_before_last_save("name")
.
Source
# File lib/active_record/attribute_methods/dirty.rb, line 152 def attribute_change_to_be_saved(attr_name) mutations_from_database.change_to_attribute(attr_name.to_s) end
Returns the change to an attribute that will be persisted during the next save.
This method is useful in validations and before callbacks, to see the change to an attribute that will occur when the record is saved. It can be invoked as name_change_to_be_saved
instead of attribute_change_to_be_saved("name")
.
If the attribute will change, the result will be an array containing the original value and the new value about to be saved.
Source
# File lib/active_record/attribute_methods/dirty.rb, line 164 def attribute_in_database(attr_name) mutations_from_database.original_value(attr_name.to_s) end
Returns the value of an attribute in the database, as opposed to the in-memory value that will be persisted the next time the record is saved.
This method is useful in validations and before callbacks, to see the original value of an attribute prior to any changes about to be saved. It can be invoked as name_in_database
instead of attribute_in_database("name")
.
Source
# File lib/active_record/attribute_methods/dirty.rb, line 191 def attributes_in_database mutations_from_database.changed_values end
Returns a hash of the attributes that will change when the record is next saved.
The hash keys are the attribute names, and the hash values are the original attribute values in the database (as opposed to the in-memory values about to be saved).
Source
# File lib/active_record/attribute_methods/dirty.rb, line 181 def changed_attribute_names_to_save mutations_from_database.changed_attribute_names end
Returns an array of the names of any attributes that will change when the record is next saved.
Source
# File lib/active_record/attribute_methods/dirty.rb, line 175 def changes_to_save mutations_from_database.changes end
Returns a hash containing all the changes that will be persisted during the next save.
Source
# File lib/active_record/attribute_methods/dirty.rb, line 169 def has_changes_to_save? mutations_from_database.any_changes? end
Will the next call to save
have any changes to persist?
Source
# File lib/active_record/attribute_methods/dirty.rb, line 63 def reload(*) super.tap do @mutations_before_last_save = nil @mutations_from_database = nil end end
reload
the record and clears changed attributes.
Source
# File lib/active_record/attribute_methods/dirty.rb, line 98 def saved_change_to_attribute(attr_name) mutations_before_last_save.change_to_attribute(attr_name.to_s) end
Returns the change to an attribute during the last save. If the attribute was changed, the result will be an array containing the original value and the saved value.
This method is useful in after callbacks, to see the change in an attribute during the save that triggered the callbacks to run. It can be invoked as saved_change_to_name
instead of saved_change_to_attribute("name")
.
Source
# File lib/active_record/attribute_methods/dirty.rb, line 86 def saved_change_to_attribute?(attr_name, **options) mutations_before_last_save.changed?(attr_name.to_s, **options) end
Did this attribute change when we last saved?
This method is useful in after callbacks to determine if an attribute was changed during the save that triggered the callbacks to run. It can be invoked as saved_change_to_name?
instead of saved_change_to_attribute?("name")
.
Options¶ ↑
from
-
When specified, this method will return false unless the original value is equal to the given value.
to
-
When specified, this method will return false unless the value will be changed to the given value.
Source
# File lib/active_record/attribute_methods/dirty.rb, line 118 def saved_changes mutations_before_last_save.changes end
Returns a hash containing all the changes that were just saved.
Source
# File lib/active_record/attribute_methods/dirty.rb, line 113 def saved_changes? mutations_before_last_save.any_changes? end
Did the last call to save
have any changes to change?
Source
# File lib/active_record/attribute_methods/dirty.rb, line 138 def will_save_change_to_attribute?(attr_name, **options) mutations_from_database.changed?(attr_name.to_s, **options) end
Will this attribute change the next time we save?
This method is useful in validations and before callbacks to determine if the next call to save
will change a particular attribute. It can be invoked as will_save_change_to_name?
instead of will_save_change_to_attribute?("name")
.
Options¶ ↑
from
-
When specified, this method will return false unless the original value is equal to the given value.
to
-
When specified, this method will return false unless the value will be changed to the given value.
Private Instance Methods
Source
# File lib/active_record/attribute_methods/dirty.rb, line 239 def _create_record(attribute_names = attribute_names_for_partial_inserts) id = super changes_applied id end
Source
# File lib/active_record/attribute_methods/dirty.rb, line 204 def _touch_row(attribute_names, time) @_touch_attr_names = Set.new(attribute_names) affected_rows = super if @_skip_dirty_tracking ||= false clear_attribute_changes(@_touch_attr_names) return affected_rows end changes = {} @attributes.keys.each do |attr_name| next if @_touch_attr_names.include?(attr_name) if attribute_changed?(attr_name) changes[attr_name] = _read_attribute(attr_name) _write_attribute(attr_name, attribute_was(attr_name)) clear_attribute_change(attr_name) end end changes_applied changes.each { |attr_name, value| _write_attribute(attr_name, value) } affected_rows ensure @_touch_attr_names, @_skip_dirty_tracking = nil, nil end
Source
# File lib/active_record/attribute_methods/dirty.rb, line 233 def _update_record(attribute_names = attribute_names_for_partial_updates) affected_rows = super changes_applied affected_rows end
Source
# File lib/active_record/attribute_methods/dirty.rb, line 249 def attribute_names_for_partial_inserts if partial_inserts? changed_attribute_names_to_save else attribute_names.reject do |attr_name| if column_for_attribute(attr_name).auto_populated? !attribute_changed?(attr_name) end end end end
Source
# File lib/active_record/attribute_methods/dirty.rb, line 245 def attribute_names_for_partial_updates partial_updates? ? changed_attribute_names_to_save : attribute_names end
Source
# File lib/active_record/attribute_methods/dirty.rb, line 196 def init_internals super @mutations_before_last_save = nil @mutations_from_database = nil @_touch_attr_names = nil @_skip_dirty_tracking = nil end