Rails Settings Cached

This a plugin that makes managing a table of а global key, value pairs easy. Think of it like a global Hash stored in your database, that uses simple ActiveRecord like methods for manipulation. Keep track of any global setting that you don't want to hard code into your rails app. You can store any kind of object. Strings, numbers, arrays, or any object.

🚨 BREAK CHANGES WARNING: rails-settings-cached 2.x has redesigned the API, the new version will compatible with the stored setting values by an older version. When you want to upgrade 2.x, you must read the README again, and follow guides to change your Setting model. 0.x stable branch: https://github.com/huacnlee/rails-settings-cached/tree/0.x

Status

Setup

Edit your Gemfile:

gem "rails-settings-cached", "~> 2.0"

Generate your settings:

$ rails g settings:install

If you want custom model name:

$ rails g settings:install

Or use a custom name:

$ rails g settings:install SiteConfig

You will get app/models/setting.rb

class Setting < RailsSettings::Base
  # cache_prefix { "v1" }

  field :host, default: "http://example.com"
  field :readonly_item, type: :integer, default: 100, readonly: true
  field :user_limits, type: :integer, default: 20
  field :admin_emails, type: :array, default: %w[admin@rubyonrails.org]
  # Override array separator, default: /[\n,]/ split with \n or comma.
  field :tips, type: :array, separator: /[\n]+/
  field :captcha_enable, type: :boolean, default: 1
  field :notification_options, type: :hash, default: {
    send_all: true,
    logging: true,
    sender_email: "foo@bar.com"
  }
end

You must use field method to statement the setting keys, otherwise you can't use it.

Now just put that migration in the database with:

rake db:migrate

Usage

The syntax is easy. First, let's create some settings to keep track of:

irb > Setting.host
"http://example.com"
irb > Setting.host = "https://your-host.com"
irb > Setting.host
"https://your-host.com"

irb > Setting.user_limits
20
irb > Setting.user_limits = "30"
irb > Setting.user_limits
30
irb > Setting.user_limits = 45
irb > Setting.user_limits
45

irb > Setting.captcha_enable
1
irb > Setting.captcha_enable?
true
irb > Setting.captcha_enable = "0"
irb > Setting.captcha_enable
false
irb > Setting.captcha_enable = "1"
irb > Setting.captcha_enable
true
irb > Setting.captcha_enable = "false"
irb > Setting.captcha_enable
false
irb > Setting.captcha_enable = "true"
irb > Setting.captcha_enable
true
irb > Setting.captcha_enable?
true

irb > Setting.admin_emails
["admin@rubyonrails.org"]
irb > Setting.admin_emails = %w[foo@bar.com bar@dar.com]
irb > Setting.admin_emails
["foo@bar.com", "bar@dar.com"]
irb > Setting.admin_emails = "huacnlee@gmail.com,admin@admin.com\nadmin@rubyonrails.org"
irb > Setting.admin_emails
["huacnlee@gmail.com", "admin@admin.com", "admin@rubyonrails.org"]

irb > Setting.notification_options
{
  send_all: true,
  logging: true,
  sender_email: "foo@bar.com"
}
irb > Setting.notification_options = {
  sender_email: "notice@rubyonrails.org"
}
irb > Setting.notification_options
{
  sender_email: "notice@rubyonrails.org"
}

Readonly field

Sometimes you may need to use Setting before Rails is initialized, for example config/devise.rb

Devise.setup do |config|
  if Setting.omniauth_google_client_id.present?
    config.omniauth :google_oauth2, Setting.omniauth_google_client_id, Setting.omniauth_google_client_secret
  end
end

In this case, you must define the readonly field:

class Setting < RailsSettings::Base
  # cache_prefix { "v1" }
  field :omniauth_google_client_id, default: ENV["OMNIAUTH_GOOGLE_CLIENT_ID"], readonly: true
  field :omniauth_google_client_secret, default: ENV["OMNIAUTH_GOOGLE_CLIENT_SECRET"], readonly: true
end

Caching flow:

Setting.host -> Check Cache -> Exist - Get value of key for cache -> Return
                   |
                Fetch all key and values from DB -> Write Cache -> Get value of key for cache -> return
                   |
                Return default value or nil

In each Setting keys call, we will load the cache/db and save in RequestStore to avoid hit cache/db.

Each key update will expire the cache, so do not add some frequent update key.

Change cache key

Some times you may need to force update cache, now you can use cache_prefix

class Setting < RailsSettings::Base
  cache_prefix { "you-prefix" }
  ...
end

In testing, you need add Setting.clear_cache for each Test case:

class ActiveSupport::TestCase
  teardown do
    Setting.clear_cache
  end
end

---

How to manage Settings in the admin interface?

If you want to create an admin interface to editing the Settings, you can try methods in following:

config/routes.rb

namespace :admin do
  resources :settings
end

app/controllers/admin/settings_controller.rb

module Admin
  class SettingsController < ApplicationController
    before_action :get_setting, only: [:edit, :update]

    def show
    end

    def create
      setting_params.keys.each do |key|
        next if key.to_s == "site_logo"
        Setting.send("#{key}=", setting_params[key].strip) unless setting_params[key].nil?
      end
      redirect_to admin_settings_path(notice: "Setting was successfully updated.")
    end


    private
      def setting_params
        params.require(:setting).permit(:host, :user_limits, :admin_emails,
          :captcha_enable, :notification_options)
      end
  end
end

app/views/admin/settings/show.html.erb

<%= form_for(Setting.new, url: admin_settings_path) do |f| %>
  <div class="form-group">
    <label class="control-label">Host</label>
    <%= f.text_field :host, value: Setting.host, class: "form-control", placeholder: "http://localhost"  %>
  </div>

  <div class="form-group form-checkbox">
    <label>
      <%= f.check_box :captcha_enable, checked: Setting.captcha_enable? %>
      Enable/Disable Captcha
    </label>
  </div>

  <div class="form-group">
    <label class="control-label">Admin Emails</label>
    <%= f.text_area :admin_emails, value: Setting.admin_emails.join("\n"), class: "form-control" %>
  </div>

  <div class="form-group">
    <label class="control-label">Notification options</label>
    <%= f.text_area :notification_options, value: YAML.dump(Setting.notification_options), class: "form-control", style: "height: 180px;"  %>
    <div class="form-text">
      Use YAML format to config the SMTP_html
    </details>
<% end %>

Backward compatible to support 0.x scoped settings

You may used the scoped setting feature in 0.x version. Before you upgrade rails-settings-cached 2.x, you must follow this guide to backward compatible it.

For example:

class User < ApplicationRecord
  include RailsSettings::Extend
end

@user.settings.color = "red"
@user.settings.foo = 123

create app/models/concerns/scoped_setting.rb

module ScopedSetting
  extend ActiveSupport::Concern

  included do
    has_many :settings, as: :thing
  end

  class_methods do
    def scoped_field(name, default: nil)
      define_method(name) do
        obj = settings.where(var: name).take || settings.new(var: name, value: default)
        obj.value
      end

      define_method("#{name}=") do |val|
        record = settings.where(var: name).take || settings.new(var: name)
        record.value = val
        record.save!

        val
      end
    end
  end
end

Now include it for your model:

class User < ApplicationRecord
  include ScopedSetting

  scoped_field :color, default: ""
  scoped_field :foo, default: 0
end

Now you must to find project with ".setting." for replace with:

Same values will fetch from the settings table.

@user.color = "red"
@user.color # => "red"
@user.foo = 123
@user.foo # =>

Use cases:

• ruby-china/ruby-china
• thebluedoc/bluedoc
• tootsuite/mastodon
• helpyio/helpy