Covercache

Covercache is a helper for Rails.cache, based on PackRat gem, and, as it says:

When included in your class it makes caching trivial.

Motivation

• Quickly use Rails.cache for some tasks without rubbish code in models.
• Don't worrying about generation and storing cache keys, but sometimes will be able to adjust it.
• Cache any queries and scopes, not only find_by and simple associations, as many caching gems provide.

Installation

Add this line to your application's Gemfile:

gem 'covercache'

And then execute:

$ bundle

Or install it yourself as:

$ gem install covercache

Usage

Add following line to your model which you want to cache:

class Post < ActiveRecord::Base
  covers_with_cache

Now you can use define_cached, class_define_cached or covercache helpers.

Method covering with covercache

Use the covercache helper inside instance and class methods. Syntax is similar to PackRat cache helper with a few additions (see source).

  has_many :comments
  scope :published, where(published: true)

  def cached_comments
    covercache do
      comments.all
    end
  end

  def self.cached_published
    covercache debug:true do
      published.all
    end
  end

Wrapping with define_cached and class_define_cached

You can easily wrap methods with the define_cached helper.
Note, that Relation objects couldn't be cached, so wrapped method or block should return an array or single instance of your model.

To wrap instance methods you should use a name of already defined method or set block with the first argument as record:

class Post < ActiveRecord::Base
  def all_comments
    comments.all
  end

  # Wrap instance method Post#all_comments to Post#cached_all_comments:
  define_cached :all_comments

  # You can add arguments like for covercache: 
  # [keys], debug: true, expires_in: 10.minutes
  define_cached :all_comments, expires_in: 1.minute

  define_cached :all_comments_authors, debug: true do |record|
    record.author
  end
  # ...
end

post = Post.find(1)
post.cached_all_comments

To wrap class methods you can also use blocks:

class_define_cached :for_post_ids, debug: true, expires_in: 10.minutes do |post_ids|
  where(post_id: post_ids).all
end

post_ids = (1..10).to_a
Comments.cached_for_post_ids post_ids, cache_key: post_ids.hash

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request