Instance Public methods
cache_key() Link
Returns a stable cache key that can be used to identify this record.
Product.new.cache_key # => "products/new"
Product.find(5).cache_key # => "products/5"
If ActiveRecord::Base.cache_versioning is turned off, as it was in Rails 5.1 and earlier, the cache key will also include a version.
Product.cache_versioning = false
Product.find(5).cache_key # => "products/5-20071224150000" (updated_at available)
# File activerecord/lib/active_record/integration.rb, line 72 def cache_key if new_record? "#{model_name.cache_key}/new" else if cache_version "#{model_name.cache_key}/#{id}" else timestamp = max_updated_column_timestamp if timestamp timestamp = timestamp.utc.to_s(cache_timestamp_format) "#{model_name.cache_key}/#{id}-#{timestamp}" else "#{model_name.cache_key}/#{id}" end end end end
cache_key_with_version() Link
Returns a cache key along with the version.
cache_version() Link
Returns a cache version that can be used together with the cache key to form a recyclable caching scheme. By default, the updated_at column is used for the cache_version
, but this method can be overwritten to return something else.
Note, this method will return nil if ActiveRecord::Base.cache_versioning is set to false
.
# File activerecord/lib/active_record/integration.rb, line 97 def cache_version return unless cache_versioning if has_attribute?("updated_at") timestamp = updated_at_before_type_cast if can_use_fast_cache_version?(timestamp) raw_timestamp_to_cache_version(timestamp) elsif timestamp = updated_at timestamp.utc.to_s(cache_timestamp_format) end elsif self.class.has_attribute?("updated_at") raise ActiveModel::MissingAttributeError, "missing attribute: updated_at" end end
to_param() Link
Returns a String
, which Action Pack uses for constructing a URL to this object. The default implementation returns this record's id as a String
, or nil
if this record's unsaved.
For example, suppose that you have a User model, and that you have a resources :users
route. Normally, user_path
will construct a path with the user object's 'id' in it:
user = User.find_by(name: 'Phusion')
user_path(user) # => "/users/1"
You can override to_param
in your model to make user_path
construct a path using the user's name instead of the user's id:
class User < ActiveRecord::Base
def to_param # overridden
name
end
end
user = User.find_by(name: 'Phusion')
user_path(user) # => "/users/Phusion"