Tags in Project Jellyfish

This document contains information on how tags are implemented in Project Jellyfish and how they can be used.

Setup Process

Add the acts-as-taggable-on (see acts-as-taggable-on) to your Gemfile:

gem 'acts-as-taggable-on'

and bundle:

bundle install

Create migrations for the tags and taggings tables that the gem requires

# For the latest (>2.4.1) versions :
rake acts_as_taggable_on_engine:install:migrations

Run migrations

rake db:migrate


Add acts_as_taggable or acts_as_taggable_on to model that we want to enable tags upon

class Product < ActiveRecord::Base
  acts_as_taggable # Alias for acts_as_taggable_on :tags
  acts_as_taggable_on :clouds, :apps

Add the following to add, remove or view tags

p = Product.where(id: 1).first
p.tag_list.add('awesome')   # add a single tag to generic tag context
p.tag_list.add('cool', 'slick')  # add a multiple tags to generic tag context
p.cloud_list.add('aws')  # add a single tag to cloud tag context
p.save # persist changes to db

# => ['awesome', 'cool', 'slick']

# => ['aws']

Context agnostic tags can be added via record.tag_list.add('tag') whereas context specific tags like :clouds can be added with the list method specific to that context - i.e. record.cloud_list.add('tag')

Finding Tagged Objects

Acts As Taggable On uses scopes to create an association for tags. This way you can mix and match to filter down your results.

class User < ActiveRecord::Base
  acts_as_taggable_on :tags, :skills
  scope :by_join_date, order("created_at DESC")

User.tagged_with("awesome").by_join_date.paginate(:page => params[:page], :per_page => 20)

# Find users that matches all given tags:
User.tagged_with(["awesome", "cool"], :match_all => true)

# Find users with any of the specified tags:
User.tagged_with(["awesome", "cool"], :any => true)

# Find users that has not been tagged with awesome or cool:
User.tagged_with(["awesome", "cool"], :exclude => true)

# Find users with any of the tags based on context:
User.tagged_with(['awesome', 'cool'], :on => :tags, :any => true).tagged_with(['smart', 'shy'], :on => :skills, :any => true)

You can also use :wild => true option along with :any or :exclude option. It will be looking for %awesome% and %cool% in SQL.

Tip: User.tagged_with([]) or User.tagged_with('') will return [], an empty set of records.

Schema Relations

Taggable Gem Schema Relationships