ActsAsTaggableOn
================

This plugin was originally based on Acts as Taggable on Steroids by Jonathan Viney.
It has evolved substantially since that point, but all credit goes to him for the
initial tagging functionality that so many people have used.

For instance, in a social network, a user might have tags that are called skills,
interests, sports, and more. There is no real way to differentiate between tags and
so an implementation of this type is not possible with acts as taggable on steroids.

Enter Acts as Taggable On. Rather than tying functionality to a specific keyword
(namely "tags"), acts as taggable on allows you to specify an arbitrary number of
tag "contexts" that can be used locally or in combination in the same way steroids
was used.

Installation
============

Plugin
------

Acts As Taggable On is available both as a gem and as a traditional plugin. For the
traditional plugin you can install like so (Rails 2.1 or later):

  script/plugin install git://github.com/mbleigh/acts-as-taggable-on.git
  
For earlier versions:

  git clone git://github.com/mbleigh/acts-as-taggable-on.git vendor/plugins/acts-as-taggable-on
  
GemPlugin
---------

Acts As Taggable On is also available as a gem plugin using Rails 2.1's gem dependencies.
To install the gem, add this to your config/environment.rb:
  
  config.gem "mbleigh-acts-as-taggable-on", :source => "http://gems.github.com", :lib => "acts-as-taggable-on"
  
After that, you can run "rake gems:install" to install the gem if you don't already have it.
See http://ryandaigle.com/articles/2008/4/1/what-s-new-in-edge-rails-gem-dependencies for
additional details about gem dependencies in Rails.

** NOTE **
Some issues have been experienced with "rake gems:install". If that doesn't work to install the gem,
try just installing it as a normal gem:

  gem install mbleigh-acts-as-taggable-on --source http://gems.github.com

Post Installation (Rails)
-------------------------
1. script/generate acts_as_taggable_on_migration
2. rake db/migrate

Testing
=======

Acts As Taggable On uses RSpec for its test coverage. If you already have RSpec on your
application, the specs will run while using:

rake spec:plugins

Example
=======

class User < ActiveRecord::Base
  acts_as_taggable_on :tags, :skills, :interests
end

@user = User.new(:name => "Bobby")
@user.tag_list = "awesome, slick, hefty"      # this should be familiar
@user.skill_list = "joking, clowning, boxing" # but you can do it for any context!
@user.skill_list # => ["joking","clowning","boxing"] as TagList
@user.save

@user.tags # => [<Tag name:"awesome">,<Tag name:"slick">,<Tag name:"hefty">]
@user.skills # => [<Tag name:"joking">,<Tag name:"clowning">,<Tag name:"boxing">]

# The old way
User.find_tagged_with("awesome", :on => :tags) # => [@user]
User.find_tagged_with("awesome", :on => :skills) # => []

# The better way (utilizes named_scope)
User.tagged_with("awesome", :on => :tags) # => [@user]
User.tagged_with("awesome", :on => :skills) # => []

@frankie = User.create(:name => "Frankie", :skill_list => "joking, flying, eating")
User.skill_counts # => [<Tag name="joking" count=2>,<Tag name="clowning" count=1>...]
@frankie.skill_counts

Finding Tagged Objects
======================

Acts As Taggable On utilizes Rails 2.1's named_scope to create an association
for tags. This way you can mix and match to filter down your results, and it
also improves compatibility with the will_paginate gem:

class User < ActiveRecord::Base
  acts_as_taggable_on :tags
  named_scope :by_join_date, :order => "created_at DESC"
end

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

Relationships
=============

You can find objects of the same type based on similar tags on certain contexts.
Also, objects will be returned in descending order based on the total number of 
matched tags.

@bobby = User.find_by_name("Bobby")
@bobby.skill_list # => ["jogging", "diving"]

@frankie = User.find_by_name("Frankie")
@frankie.skill_list # => ["hacking"]

@tom = User.find_by_name("Tom")
@tom.skill_list # => ["hacking", "jogging", "diving"]

@tom.find_related_skills # => [<User name="Bobby">,<User name="Frankie">]
@bobby.find_related_skills # => [<User name="Tom">] 
@frankie.find_related_skills # => [<User name="Tom">] 


Dynamic Tag Contexts
====================

In addition to the generated tag contexts in the definition, it is also possible
to allow for dynamic tag contexts (this could be user generated tag contexts!)

@user = User.new(:name => "Bobby")
@user.set_tag_list_on(:customs, "same, as, tag, list")
@user.tag_list_on(:customs) # => ["same","as","tag","list"]
@user.save
@user.tags_on(:customs) # => [<Tag name='same'>,...]
@user.tag_counts_on(:customs)
User.find_tagged_with("same", :on => :customs) # => [@user]

Tag Ownership
=============

Tags can have owners:

class User < ActiveRecord::Base
  acts_as_tagger
end

class Photo < ActiveRecord::Base
  acts_as_taggable_on :locations
end

@some_user.tag(@some_photo, :with => "paris, normandy", :on => :locations)
@some_user.owned_taggings
@some_user.owned_tags
@some_photo.locations_from(@some_user)

Caveats, Uncharted Waters
=========================

This plugin is still under active development. Tag caching has not 
been thoroughly (or even casually) tested and may not work as expected.

Contributors
============

* Michael Bleigh - Original Author
* Brendan Lim - Related Objects
* Pradeep Elankumaran - Taggers
* Sinclair Bain - Patch King

Patch Contributors
------------------

* tristanzdunn - Related objects of other classes
* azabaj - Fixed migrate down
* Peter Cooper - named_scope fix
* slainer68 - STI fix
* harrylove - migration instructions and fix-ups
* lawrencepit - cached tag work

Resources
=========

* Acts As Community - http://www.actsascommunity.com/projects/acts-as-taggable-on
* GitHub - http://github.com/mbleigh/acts-as-taggable-on
* Lighthouse - http://mbleigh.lighthouseapp.com/projects/10116-acts-as-taggable-on

Copyright (c) 2007 Michael Bleigh (http://mbleigh.com/) and Intridea Inc. (http://intridea.com/), released under the MIT license