# 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.
[](https://rubygems.org/gems/rails-settings-cached) [](http://travis-ci.org/huacnlee/rails-settings-cached) [](https://codecov.io/github/huacnlee/rails-settings-cached?branch=master)
## Installation
Edit your Gemfile:
```bash
$ bundle add rails-settings-cached
```
Generate your settings:
```bash
$ rails g settings:install
# Or use a custom name:
$ rails g settings:install AppConfig
```
You will get `app/models/setting.rb`
```rb
class Setting < RailsSettings::Base
# cache_prefix { "v1" }
field :app_name, default: "Rails Settings"
field :host, default: "http://example.com", readonly: true
field :default_locale, default: "zh-CN"
field :readonly_item, type: :integer, default: 100, readonly: true
field :user_limits, type: :integer, default: 20
field :exchange_rate, type: :float, default: 0.123
field :admin_emails, type: :array, default: %w[admin@rubyonrails.org]
field :captcha_enable, type: :boolean, default: true
# Override array separator, default: /[\n,]/ split with \n or comma.
field :tips, type: :array, separator: /[\n]+/
field :notification_options, type: :hash, default: {
send_all: true,
logging: true,
sender_email: "foo@bar.com"
}
# lambda default value
field :welcome_message, type: :string, default: -> { "welcome to #{self.app_name}" }
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:
```bash
$ rails db:migrate
```
## Usage
The syntax is easy. First, let's create some settings to keep track of:
```ruby
irb > Setting.host
"http://example.com"
irb > Setting.app_name
"Rails Settings"
irb > Setting.app_name = "Rails Settings Cached"
irb > Setting.app_name
"Rails Settings Cached"
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"
}
```
### Get defined fields
> version 2.3+
```rb
# Get all keys
Setting.keys
=> ["app_name", "host", "default_locale", "readonly_item"]
# Get editable keys
Settng.editable_keys
=> ["app_name", "default_locale"]
# Get readonly keys
Setting.readonly_keys
=> ["host", "readonly_item"]
# Get options of field
Setting.get_field("host")
=> { key: "host", type: :string, default: "http://example.com", readonly: true }
Setting.get_field("app_name")
=> { key: "app_name", type: :string, default: "Rails Settings", readonly: false }
```
## Readonly field
Sometimes you may need to use Setting before Rails is initialized, for example `config/devise.rb`
```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:
```rb
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](https://github.com/steveklabnik/request_store) 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`
```ruby
class Setting < RailsSettings::Base
cache_prefix { "you-prefix" }
...
end
```
In testing, you need add `Setting.clear_cache` for each Test case:
```rb
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
```rb
namespace :admin do
resource :settings
end
```
app/controllers/admin/settings_controller.rb
```rb
module Admin
class SettingsController < ApplicationController
before_action :get_setting, only: [:edit, :update]
def create
setting_params.keys.each do |key|
Setting.send("#{key}=", setting_params[key].strip) unless setting_params[key].nil?
end
redirect_to 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
```erb
<%= form_for(Setting.new, url: admin_settings_path) do |f| %>
<% end %>
```
## Scoped Settings
> 🚨 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
- [Backward compatible to support 0.x scoped settings](docs/backward-compatible-to-scoped-settings.md)
For new project / new user of rails-settings-cached. The [ActiveRecord::AttributeMethods::Serialization](https://api.rubyonrails.org/classes/ActiveRecord/AttributeMethods/Serialization/ClassMethods.html#method-i-serialize) is best choice.
> This is reason of why rails-settings-cached 2.x removed **Scoped Settings** feature.
For example:
We wants a preferences setting for user.
```rb
class User < ActiveRecord::Base
serialize :preferences
end
@user = User.new
@user.preferences[:receive_emails] = true
@user.preferences[:public_email] = true
@user.save
```
## Use cases:
- [ruby-china/homeland](https://github.com/ruby-china/homeland) - master
- [forem/forem](https://github.com/forem/forem) - 2.x
- [siwapp/siwapp](https://github.com/siwapp/siwapp) - 2.x
- [aidewoode/black_candy](https://github.com/aidewoode/black_candy) - 2.x
- [thebluedoc/bluedoc](https://github.com/thebluedoc/bluedoc/blob/master/app/models/setting.rb) - 2.x
- [tootsuite/mastodon](https://github.com/tootsuite/mastodon) - 0.6.x
- [helpyio/helpy](https://github.com/helpyio/helpy) - 0.5.x
And more than [1K repositories](https://github.com/huacnlee/rails-settings-cached/network/dependents) used.