Module: ActiveRecord::Integration

Extended by:
ActiveSupport::Concern
Included in:
Base
Defined in:
activerecord/lib/active_record/integration.rb

Defined Under Namespace

Modules: ClassMethods

Instance Method Summary collapse

Methods included from ActiveSupport::Concern

append_features, class_methods, extended, included, prepend_features, prepended

Instance Method Details

#cache_keyObject

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)

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# 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_versionObject

Returns a cache key along with the version.


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# File 'activerecord/lib/active_record/integration.rb', line 115

def cache_key_with_version
  if version = cache_version
    "#{cache_key}-#{version}"
  else
    cache_key
  end
end

#cache_versionObject

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.


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# 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
  else
    if self.class.has_attribute?("updated_at")
      raise ActiveModel::MissingAttributeError, "missing attribute: updated_at"
    end
  end
end

#to_paramObject

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"

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# File 'activerecord/lib/active_record/integration.rb', line 57

def to_param
  # We can't use alias_method here, because method 'id' optimizes itself on the fly.
  id && id.to_s # Be sure to stringify the id for routes
end