Module: Pod4::Tweaking

Defined in:
lib/pod4/tweaking.rb

Overview

A mixin that extends the model DSL to simplify use of custom interface methods.

We add one command to the model DSL: set_custom_list. It’s optional.

set_custom_list

class Bar < Pod4::Model
  include Pod4::Tweaking

  class Interface < Pod4::PgInterface
    set table :bar
    set_id_field :id, autoincrement: true

    # Example custom interface method
    def list_paged(drop=0, limit=15)
      execute %Q|select * from bar offset #{drop} rows fetch next #{limit} rows only;|
    end
  end # of Interface

  set_interface   Interface.new($conn)
  set_custom_list :list_paged
end

Use this when you want to make a special version of the List action. It takes one parameter: the name of a custom method you have defined on the Interface. A corresponding method will be created on the model. Any parameters you pass to the model method will be passed on to your custom interface method.

Your custom interface method should return an array of Octothorpes or Hashes; the corresponding model method will return an array of instances of the model, just as #list does.

Obviously this means that the keys in your array of Hash/Octothorpe must match the column attributes in the model. Any missing attributes will be set to nil; any extra attributes will be ignored. But the ID field must be present as a key, or else an exception will be raised. if you want to indicate that no records were found, you must return an empty Array and not nil.

Just as with List proper, the array of model instances have not had validation run against them, and are all status :empty.

Defined Under Namespace

Modules: ClassMethods

Class Method Summary collapse

Class Method Details

.included(base) ⇒ Object

A little bit of magic, for which I apologise.

When you include this module it actually adds the methods in ClassMethods to the class as if you had called ‘extend TypeCasting:ClassMethds` AND (theoretically, in this case) adds the methods in InstanceMethods as if you had written `prepend TypeCasting::InstanceMethods`.

In my defence: I didn’t want to have to make you remember to do that…



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# File 'lib/pod4/tweaking.rb', line 61

def self.included(base)
  base.extend ClassMethods
#     base.send(:prepend, InstanceMethods)
end