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Settings Plugin

Settings is a plugin that makes managing a table of global key, value pairs easy. Think of it like a global Hash stored in you database, that uses simple ActiveRecord like methods for manipulation. Keep track of any global setting that you dont want to hard code into your rails app. You can store any kind of object. Strings, numbers, arrays, or any object.



Rails 3.0.x

You can add this gem in your Gemfile

gem 'rails3-settings', '~> 1.0.0', :require => 'settings'

You must create the table used by the Settings model. Simply run this command:

rails generate settings_migration

Now just put that migration in the database with:

rake db:migrate

If you use some older version of this fork, beware that the database schema needs to be changed (“object_id” renamed to “target_id”, “object_type” renamed to “target_type”). You can do this with this migration:

class RenameSettingsFields < ActiveRecord::Migration
  def self.up
    remove_index :settings, [ :object_type, :object_id, :var ]

    rename_column :settings, :object_id, :target_id
    rename_column :settings, :object_type, :target_type

    add_index :settings, [ :target_type, :target_id, :var ], :unique => true

  def self.down
    # ...


The syntax is easy. First, lets create some settings to keep track of:

Settings.admin_password = 'supersecret'
Settings.date_format    = '%m %d, %Y'
Settings.cocktails      = ['Martini', 'Screwdriver', 'White Russian']            = 123
Settings.credentials    = { :username => 'tom', :password => 'secret' }

Now lets read them back:            # returns 123

Changing an existing setting is the same as creating a new setting: = 'super duper bar'

For changing an existing setting which is a Hash, you can merge new values with existing ones:

Settings.merge! :credentials, :password => 'topsecret'
Settings.credentials    # returns { :username => 'tom', :password => 'topsecret' }

Decide you dont want to track a particular setting anymore?

Settings.destroy :foo            # returns nil

Want a list of all the settings?

Settings.all            # returns {'admin_password' => 'super_secret', 'date_format' => '%m %d, %Y'}

You need name spaces and want a list of settings for a give name space? Just choose your prefered named space delimiter and use Settings.all like this:

Settings['preferences.color'] = :blue
Settings['preferences.size'] = :large
Settings['license.key'] = 'ABC-DEF'
Settings.all('preferences.')   # returns { 'preferences.color' => :blue, 'preferences.size' => :large }

Set defaults for certain settings of your app. This will cause the defined settings to return with the Specified value even if they are not in the database. Make a new file in config/initializers/settings.rb with the following:

Settings.defaults[:some_setting] = 'footastic'

Now even if the database is completely empty, you app will have some intelligent defaults:

Settings.some_setting   # returns 'footastic'

Settings may be bound to any existing ActiveRecord object. Define this association like this:

class User < ActiveRecord::Base

Then you can set/get a setting for a given user instance just by doing this:

user = User.find(123)
user.settings.color = :red
user.settings.color # returns :red
user.settings.all # { "color" => :red }

I you want to find users having or not having some settings, there are named scopes for this:

User.with_settings # => returns a scope of users having any setting
User.with_settings_for('color') # => returns a scope of users having a 'color' setting

User.without_settings # returns a scope of users having no setting at all (means user.settings.all == {})
User.without_settings('color') # returns a scope of users having no 'color' setting (means user.settings.color == nil)

That's all there is to it! Enjoy!