StoreConfigurable

A zero-configuration recursive Hash for storing a tree of options in a serialized ActiveRecord column. Includes self aware hooks that delegate dirty/changed state to your configs owner. Read my article A Lesson In Recursion In Ruby if you are interested in how this library works.

Installation

Install the gem with bundler. We follow a semantic versioning format that tracks ActiveRecord's minor version. So this means to use the latest 3.2.x version of StoreConfigurable with any ActiveRecord 3.2 version.

gem 'store_configurable', '~> 4.0.0'

Our 4.0.x versions target both Rails 4.0 and 4.1 only.

Setup

To use StoreConfigurable, you must create a _config column in the model's table. Make sure that you declare this column as a text type, so there's plenty of room.

class AddStoreConfigurableField < ActiveRecord::Migration
  def up
    add_column :users, :_config, :text
  end
  def down
    remove_column :users, :_config
  end
end

Next declare that your model uses StoreConfigurable with the store_configurable method.

class User < ActiveRecord::Base
  store_configurable
end

Usage

Our config method is your gateway to StoreConfigurable and unlike ActiveRecord's new Store object in 3.2, there is no configuration needed to start using it for any property. It will dynamically expand for every property or namespace. This allows you or other plugins' configurations to be grouped in logical nodes. All examples below assume that StoreConfigurable is being used on a User instance as shown in the setup above.

@user.config.remember_me = true
@user.config.sortable_tables.column    = 'created_at'
@user.config.sortable_tables.direction = 'asc'
@user.config.you.should.never.need.to.do.this.but.you.could.if.you.wanted.to = 'deep_value'
@user.save

Dirty Hooks

StoreConfigurable is smart enought to let your parent object know when it changes. It is not dumb either. It will only trigger changes if the values you set are different, are new, or change the configs state. Some examples assuming the saved record's data above.

@user = User.find(42)
@user.config_changed? # => false

@user.config.remember_me = true   # Same value
@user.config_changed?             # => false

@user.config.sortable_tables.column    = 'updated_at'
@user.config.sortable_tables.direction = 'desc'
@user.config_changed? # => true

Hash Syntax

The StoreConfigurable data objects supports most Hash methods with the exception of a few that rely on making a copy of the data, like dup. This means you can delete whole branches of data or itterate over your data collection. Again, StoreConfigurable reports all changes to the owner object via ActiveRecord's dirty support.

@user.config.sortable_tables.delete   # Deletes this node/namespace.
@user.config.clear                    # Hash method to purge.
@user.config_changed?                 # => true

Choose Your Style

You can choose to get or set config values via any method or hash key syntax you choose. It really does not matter! This means you can mix and match dot property notation, hash string or symbol syntax and it will just work.

@user.config.color = '#c1c1c1'
@user.config['remember_me'] = true
@user.config[:sortable_tables].direction = 'asc'
@user.config.sortable_tables['column'] = 'updated_at'

@user.config['color']                       # => '#c1c1c1'
@user.config[:color]                        # => '#c1c1c1'
@user.config.remember_me                    # => true
@user.config.sortable_tables[:direction]    # => 'asc'
@user.config[:sortable_tables][:column]     # => 'updated_at'

Stored Data

StoreConfigurable persists your configuration data in YAML format to the _config text column. We use Ruby's YAML::Omap type on the backend so we can decouple our datastore from our proxy object manager. This means you can easily load this data via other means if you want to.

--- !omap
- :remember_me: true
- :sortable_tables: !omap
  - :column: created_at
  - :direction: asc
- :you: !omap
  - :should: !omap
    - :never: !omap
      - :need: !omap
        - :to: !omap
          - :do: !omap
            - :this: deep_value

Todo

• Incorporate an option to compress serialized data. Gzip, MessagePack, Etc...

Other Solutions

• StoreField - Similar approach but no dirty tracking and still requires manual key configs.

Contributing

StoreConfigurable is fully tested with ActiveRecord 3.2 to 4.0 and upward. If you detect a problem, open up a github issue or fork the repo and help out. After you fork or clone the repository, the following commands will get you up and running on the test suite.

$ bundle install
$ bundle exec appraisal update
$ bundle exec appraisal rake test

We use the appraisal gem from Thoughtbot to help us generate the individual gemfiles for each ActiveSupport version and to run the tests locally against each generated Gemfile. The rake appraisal test command actually runs our test suite against all ActiveRecord versions in our Appraisal file. If you want to run the tests for a specific ActiveRecord version, use rake -T for a list. For example, the following command will run the tests for Rails 3.2 only.

$ bundle exec appraisal activerecord40 rake test

License

• Released under the MIT license thanks to Decisiv, Inc.
• Copyright (c) 2014 Ken Collins