https://github.com/cedric/custom_counter_cache

Custom counter_cache functionality that supports conditions and multiple models.
https://github.com/cedric/custom_counter_cache

Last synced: 13 days ago
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Custom counter_cache functionality that supports conditions and multiple models.

• Host: GitHub
• URL: https://github.com/cedric/custom_counter_cache
• Owner: cedric
• License: mit
• Created: 2011-02-24T20:34:12.000Z (over 13 years ago)
• Default Branch: master
• Last Pushed: 2023-08-16T17:13:31.000Z (about 1 year ago)
• Last Synced: 2024-10-01T10:46:54.969Z (about 1 month ago)
• Language: Ruby
• Homepage: https://github.com/cedric/custom_counter_cache
• Size: 117 KB
• Stars: 60
• Watchers: 1
• Forks: 20
• Open Issues: 10
• Metadata Files:
  • Readme: README.rdoc
  • License: LICENSE

Awesome Lists containing this project

• awesome-rails-gem - custom_counter_cache - A simple approach to creating a custom counter cache that can be used across multiple models. (Active Record / Omniauth)

README

        
{}[http://badge.fury.io/rb/custom_counter_cache]

{}[https://travis-ci.org/cedric/custom_counter_cache]

== Custom Counter Cache

This is a simple approach to creating a custom counter cache in Rails that can be used across multiple models.

=== Installation

Add the following to your Gemfile:

  gem 'custom_counter_cache'

=== Example

== Class with counter cache

This is the block that will be used to calculate the value for the counter cache. It will be called by other models through their association via an after_save or after_destroy callback.

  include CustomCounterCache::Model

  define_counter_cache :articles_count do |user|

    user.articles.where(state: 'published').count

  end

== Class with callbacks

This will define the after_create, after_update and after_destroy callbacks. An :if option can be provided to limit when these callbacks get triggered.

  include CustomCounterCache::Model

  update_counter_cache :user, :articles_count, if: -> (article) { article.state_changed? }

These callbacks can be added to any number of models that might need to change the counter cache.

== Counter Cache

To store the counter cache you need to create a column for the model with the counter cache (example: articles_count).

If you would like to store all of your counter caches in a single table, you can use this migration:

  create_table :counters do |t|

    t.references :countable, polymorphic: true

    t.string :key, null: false

    t.integer :value, null: false, default: 0

    t.timestamps

  end

  add_index :counters, [ :countable_id, :countable_type, :key ], unique: true

Here is the example model to go with:

  class Counter < ActiveRecord::Base

    belongs_to :countable, polymorphic: true

    validates :countable, presence: true

  end

If you would like to store your counter cache in an existing table, you can use this migration:

  def change

    add_column :users, :articles_count, :integer, default: 0, null: false

  end

To backfill your counters, run something like this either in a migration or in the console:

  User.select(:id).find_each(batch_size: 100) { |u| u.update_articles_count }