Module: Sequel::Plugins::AssociationProxies

Defined in:

lib/sequel/plugins/association_proxies.rb

Overview

Sequel by default does not use proxies for associations. The association method for *_to_many associations returns an array, and the association_dataset method returns a dataset. This plugin makes the association method return a proxy that will load the association and call a method on the association array if sent an array method, and otherwise send the method to the association’s dataset.

You can override which methods to forward to the dataset by passing a block to the plugin:

plugin :association_proxies do |opts|
  [:find, :where, :create].include?(opts[:method])
end

If the block returns false or nil, the method is sent to the array of associated objects. Otherwise, the method is sent to the association dataset. Here are the entries in the hash passed to the block:

:method

The name of the method

:arguments

The arguments to the method

:block

The block given to the method

:instance

The model instance related to the call

:reflection

The reflection for the association related to the call

:proxy_argument

The argument given to the association method call

:proxy_block

The block given to the association method call

For example, in a call like:

artist.albums(1){|ds| ds}.foo(2){|x| 3}

The opts passed to the block would be:

{
  :method => :foo,
  :arguments => [2],
  :block => {|x| 3},
  :instance => artist,
  :reflection => {:name=>:albums} # AssociationReflection instance 
  :proxy_argument => 1,
  :proxy_block => {|ds| ds}
}

Usage:

# Use association proxies in all model subclasses (called before loading subclasses)
Sequel::Model.plugin :association_proxies

# Use association proxies in a specific model subclass
Album.plugin :association_proxies

Defined Under Namespace

Modules: ClassMethods Classes: AssociationProxy

Class Method Summary

• .configure(model, &block) ⇒ Object

Class Method Details

.configure(model, &block) ⇒ Object

# File 'lib/sequel/plugins/association_proxies.rb', line 53

def self.configure(model, &block)
  model.instance_eval do
    @association_proxy_to_dataset = block if block
    @association_proxy_to_dataset ||= AssociationProxy::DEFAULT_PROXY_TO_DATASET
  end
end