Module Sequel::Plugins::AssociationProxies
In: lib/sequel/plugins/association_proxies.rb

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 => 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

Methods

configure   method_missing   new  

Classes and Modules

Class Sequel::Plugins::AssociationProxies::AssociationProxy

Public Class methods

configure(model, &block)

[Source]

    # File lib/sequel/plugins/association_proxies.rb, line 53
53:       def self.configure(model, &block)
54:         model.instance_exec do
55:           @association_proxy_to_dataset = block if block
56:           @association_proxy_to_dataset ||= AssociationProxy::DEFAULT_PROXY_TO_DATASET
57:         end
58:       end
new(instance, reflection, proxy_argument, &proxy_block)

Set the association reflection to use, and whether the association should be reloaded if an array method is called.

[Source]

    # File lib/sequel/plugins/association_proxies.rb, line 84
84:         def initialize(instance, reflection, proxy_argument, &proxy_block)
85:           @instance = instance
86:           @reflection = reflection
87:           @proxy_argument = proxy_argument
88:           @proxy_block = proxy_block
89:         end

Public Instance methods

method_missing(meth, *args, &block)

Call the method given on the array of associated objects if the method is an array method, otherwise call the method on the association‘s dataset.

[Source]

     # File lib/sequel/plugins/association_proxies.rb, line 93
 93:         def method_missing(meth, *args, &block)
 94:           v = if @instance.model.association_proxy_to_dataset.call(:method=>meth, :arguments=>args, :block=>block, :instance=>@instance, :reflection=>@reflection, :proxy_argument=>@proxy_argument, :proxy_block=>@proxy_block)
 95:             @instance.public_send(@reflection[:dataset_method])
 96:           else
 97:             @instance.send(:load_associated_objects, @reflection, @proxy_argument, &@proxy_block)
 98:           end
 99:           v.public_send(meth, *args, &block)
100:         end

[Validate]