Tanker - IndexTank integration to your favorite orm

IndexTank is a great search indexing service, this gem tries to make any orm keep in sync with indextank with ease. This gem has a simple but powerful approach to integrating IndexTank to any orm. The gem also supports pagination using the will_paginate/collection.

There are very few things needed to integrate Tanker to any orm. Basically the orm instance must respond to id and any attributes you wish to index.

Installation

gem install tanker

If you are using Rails 3 its better to add Tanker to your GEMFILE

gem 'tanker'

And run

bundle install

Initialization

If you’re using Rails, config/initializers/tanker.rb is a good place for this:

YourAppName::Application.config.index_tank_url = 'http://:[email protected]'

If you are not using rails you can put this somewhere before you load your modesl

Tanker.configuration = {:url => 'http://:[email protected]' }

You would probably want to have a fancier configuration depending on your environment. Be sure to copy and paste the correct url provided in the IndexTank Dashboard

Example

class Topic < ActiveRecord::Base
  acts_as_taggable
  has_many :authors

  # just include the Tanker module
  include Tanker

  # define the index by supplying the index name and the fields to index
  # this is the index name you create in the Index Tank dashboard
  # you can use the same index for various models Tanker can handle
  # indexing searching on different models with a single Index Tank index
  tankit 'my_index' do
    indexes :title
    indexes :content
    indexes :id
    indexes :tag_list #NOTICE this is an array of Tags! Awesome!

    # you may also dynamically retrieve field data
    indexes :author_names do
      authors.map {|author| author.name }
    end

    # to pass in a list of variables with your document,
    # supply a hash with the variable integers as keys:
    variables do
      {
        0 => authors.first.id, # these will be available in your queries
        1 => id                # as doc.var[0] and doc.var[1]
      }
    end

    # You may defined some server-side functions that can be
    # referenced in your queries. They're always referenced by
    # their integer key:
    functions do
      {
        1 => '-age',
        2 => 'doc.var[0] - doc.var[1]'
      }
    end
  end

  # define the callbacks to update or delete the index
  # these methods can be called whenever or wherever
  # this varies between ORMs
  after_save :update_tank_indexes
  after_destroy :delete_tank_indexes

  # Note! Will Paginate pagination, thanks mislav!
  def self.per_page
    5
  end

end

Create Topics

Topic.create(:title => 'Awesome Topic', :content => 'blah, blah', :tag_list => 'tag1, tag2')
Topic.create(:title => 'Bad Topic', :content => 'blah, blah', :tag_list => 'tag1')
Topic.create(:title => 'Cool Topic', :content => 'blah, blah', :tag_list => 'tag3, tag2')

Search Topics

@topics = Topic.search_tank('Topic', :page => 1, :per_page => 10) # Gets 3 results!
@topics = Topic.search_tank('blah',  :conditions => {:tag_list => 'tag1'}) # Gets 2 results!
@topics = Topic.search_tank('blah',  :conditions => {:title => 'Awesome', :tag_list => 'tag1'}) # Gets 1 result!

Search multiple models

@results = Tanker.search([Topic, Post], 'blah') # Gets any Topic OR Post results that match!

Search with negative conditions

@topics = Topic.search_tank('keyword',  :conditions => {'tag_list' => 'tag1'}) # Gets 1 result!
@topics = Topic.search_tank('keyword',  :conditions => {'-id' => [5,9]}) # Ignores documents with ids of '5' or '9'

Search with query variables

@topics = Topic.search_tank('keyword',  :variables => {0 => 5.6}) # Makes 5.6 available server-side as q[0]

Paginate Results

<% will_paginate(@topics) %>

Geospatial Search Example

IndexTank and the Tanker gem support native geographic calculations. All you need is to define two document variables with your latitude and your longitude

class Restaurant < ActiveRecord::Base
  include Tanker

  tankit 'my_index' do
    indexes :name

    # You may define lat/lng at any variable number you like, as long
    # as you refer to them consistently with the same integers
    variables do
      {
        0 => lat
        1 => lng
      }
    end

    functions do
      {
        # This function is good for sorting your results. It will
        # rank relevant, close results higher and irrelevant, distant results lower
        1 => "relevance / miles(d[0], d[1], q[0], q[1])",

        # This function is useful for limiting the results that your query returns.
        # It just calculates the distance of each document in miles, which you can use
        # in your query. Notice that we're using 0 and 1 consistently as 'lat' and 'lng'
        2 => "miles(d[0], d[1], q[0], q[1])"
      }
    end
  end
end

# When searching, you need to provide a latitude and longitude in the query so that
# these variables are accessible on the server.
Restaurant.search("tasty",
                  :var0 => 47.689948,
                  :var1 => -122.363684,
                  # And we'll return all results sorted by distance
                  :function => 1)

# Or we can use just function 2 to return results in the default order, while
# limiting the total results to just those within 50 miles from our lat/lng:
Restaurant.search("tasty",
                  :var0 => 47.689948,
                  :var1 => -122.363684,
                  # the following is a fancy way of saying "return all results where
                  the result of function 2 is at least anything and less than 50"
                  :filter_functions => {2 => [['*', 50]]})
# And we can combine these two function calls to return only results within 50 miles
# and sort them by relevance / distance:
Restaurant.search("tasty",
                  :var0 => 47.689948,
                  :var1 => -122.363684,
                  :function => 1,
                  :filter_functions => {2 => [['*', 50]]})

Reindex your data

If you are using rails 3 there are of couple of rake tasks included in your project

rake tanker:clear_indexes

This task deletes all your indexes and recreates empty indexes, if you have not created the indexes in the Index Tank interface this task creates them for you provided you have enough indexes in your account.

rake tanker:reindex

This task pushes any functions you’ve defined in your tankit() blocks to indextank.com

rake tanker:functions

This task re-indexes all the your models that have the Tanker module included. Usually you will only need a single Index Tank index but if you want to separate your indexes please use different index names in the tankit method call in your models

To reindex just one class rather than all the classes in your application just call:

Model.tanker_reindex

And if you’d like to specify a custom number of records to PUT with each call to indextank.com you may specify it as the first argument:

Model.tanker_reindex(:batch_size => 1000) # defaults to batch size of 200

Or you can restrict indexing to a subset of records. This is particularly helpful for massive datasets where only a small portion of the records is useful.

Model.tanker_reindex(:batch_size => 1000, :scope => :not_deleted) # will call Model.not_deleted.all internally

TODO

Documentation
More fancy stuff (Suggestions?)

Note on Patches/Pull Requests

Fork the project.
Make your feature addition or bug fix.
Add tests for it. This is important so I don’t break it in a future version unintentionally.
Commit, do not mess with rakefile, version, or history. (if you want to have your own version, that is fine but bump version in a commit by itself I can ignore when I pull)
Send me a pull request. Bonus points for topic branches.

Acknowledgements

The gem is based on a couple of projects:

*redis-textsearch *mongomapper *thinkingtank *will_paginate

Kudos to this awesome projects and developers