Lifesaver

Asynchronously sends your ActiveRecord models for reindexing in elasticsearch by making use of tire and resque (hence the name: resque + tire = lifesaver). Lifesaver also provides the ability to traverse ActiveRecord associations to trigger the index updates of related models.

Installation

Add this line to your application's Gemfile:

gem 'lifesaver'

And then execute:

$ bundle

Or install it yourself as:

$ gem install lifesaver

Usage

Replaces the tire callbacks in your models

    class Article < ActiveRecord::Base
      include Tire::Model::Search
      # Replace the following include with Lifesaver
      # include Tire::Model::Callbacks
      enqueues_indexing
    end

Configuring Indexing Behavior

You can suppress index updates on a per-model basis or globally using Lifesaver.suppress_indexing (to turn suppression back off, you would use Lifesaver.unsuppress_indexing). Lifesaver exposes two instance methods on the model level (supress_indexing, unsuppress_indexing) that set a model's indexing behavior for life of that instance.

    class ArticlesController < ApplicationController
      def suppressed_update
        @article = Article.find(params[:id])
        @article.attributes = params[:article]

        # No reindexing will occur at all
        @article.suppress_indexing

        @article.save!

        # Not neccessary but if saved
        # after this following call,
        # this article would reindex
        @article.unsuppress_indexing
      end
    end

ActiveRecord Association Traversal

Lifesaver can trigger other models to reindex if you have nested models in your indexes that you would like to update. Use the notifies_for_indexing method to indicate which related models should be marked for indexing. Any associations passed will be both updated when a model is changed (save or destroy) and when another model notifies it. Any associations passed in the options will only notify when the model is changed or notified when specified in the only_on_change or only_on_notify keys, respectively.

    class Article < ActiveRecord::Base
      belongs_to :author
      belongs_to :category
      has_many :watchers
      has_one :moderator
      
      notifies_for_indexing :author, 
        only_on_change: :category,
        only_on_notify: [:watchers, :moderator]
    end

Integration with Tire

Lifesaver will not execute any <after|before>_update_elasticsearch_index callback hooks. Lifesaver also does not currently support percolation.

Integration with Resque

You will see two new queues: lifesaver_indexing and lifesaver_notification. The queue names are configurable.

Testing

In your spec_helper, you should place something similar to the following to make sure Lifesaver isn't spawning up indexing jobs unless you want it to.

    config.before(:each) do
      Lifesaver.suppress_indexing
    end

Then, when your tests need Lifesaver to run, you should make sure you unsuppress indexing in a before block. You may also want to run Resque inline.

  describe 'some test' do
    before { Lifesaver.unsuppress_indexing }
    # tests go here
  end

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

TODO

Please visit TODO page here