This plugin adds full text search capabilities and many other nifty features from Apache's Solr to any Rails model. It was based on the first draft by Erik Hatcher.

script/plugin install git://github.com/dcrec1/acts_as_solr_reloaded.git

• Java Runtime Environment(JRE) 1.6 aka 6.0 or newer http://www.java.com/en/download/index.jsp
• If you have libxml-ruby installed, make sure it's at least version 0.7

If you are using acts_as_solr as a Rails plugin, everything is configured to work out of the box. You can use rake solr:start and rake solr:stop to start and stop the Solr web server (an embedded Jetty). If the default JVM options aren't suitable for your environment, you can configure them in solr.yml with the option jvm_options. There is a default set for the production environment to have some more memory available for the JVM than the defaults, but feel free to change them to your liking.

If you are using acts_as_solr as a gem, create a file named lib/tasks/acts_as_solr.rake:

require "acts_as_solr/tasks"

# Just include the line below to any of your ActiveRecord models:
  acts_as_solr

# Or if you want, you can specify only the fields that should be indexed:
  acts_as_solr :fields => [:name, :author]

# Then to find instances of your model, just do:
  Model.search(query) #query is a string representing your query

# Please see ActsAsSolr::ActsMethods for a complete info

To test code that uses acts_as_solr you must start a Solr server for the test environment. You can do that with rake solr:start RAILS_ENV=test

However, if you would like to mock out Solr calls so that a Solr server is not needed (and your tests will run much faster), just add this to your test_helper.rb or similar:

class ActsAsSolr::Post
  def self.execute(request)
    true
  end
end

(via)

Released under the MIT license.