richardvenneman / cache_with_settings

🎎 Configurable Rails fragment caching

CacheWithSettings

CacheWithSettings allows you to add any key to partial caching cache keys. This is useful if your website is multilingual or allows the user to choose a display currency.

Problem & Solution

If you find yourself adding dynamic values, such as locales and currencies to your cache keys, this gem could be useful for you. Instead of:

  = cache [@user, I18n.locale, MoneyRails.default_currency] do
    = render @user

Configure this gem once and just write:

  = cache @user do
    = render @user

This gem allows you to DRY up your code and forget about including dynamic values in your cache keys.

Usage

After adding the gem to your Gemfile, configure CacheWithSettings in an initializer. You can specify any dynamic cache keys, such as I18n.locale.

CacheWithSettings.configure do |config|
  # Specify a proc that returns an array of strings
  config.cache_keys = -> { [I18n.locale.to_s, MoneyRails.default_currency.to_s] }
end

That's it! Your template cache calls now automatically include the specified cache keys.

Collection caching is also supported. If you're rendering collections with cached: true your specified cache keys will automatically be included:

<%= render partial: "cities/city",
           collection: @cities,
           cached: true %>

HTTP Caching

If you're using a HTTP cache in production (with Rails conditional get), add the dynamic cache keys with the etag directive:

class ApplicationController
  etag { CacheWithSettings.cache_keys.call.join("-") }
end

Installation

Add this line to your application's Gemfile:

gem 'cache_with_settings'

And then execute:

$ bundle

Credit

This project started as a fork of cache_with_locale. Besides the locale I also needed the current currency as part of our cache keys, which led to the creation of this gem.

License

The gem is available as open source under the terms of the MIT License.