# Merit Gem: Reputation rules (badges, points and rankings) for Rails applications
[](http://travis-ci.org/tute/merit)
# Installation
1. Add `gem 'merit'` to your `Gemfile`
2. Run `rails g merit:install`
3. Run `rails g merit MODEL_NAME` (e.g. `user`)
4. Run `rake db:migrate`
5. Define badges you will use in `config/initializers/merit.rb`
6. Configure reputation rules for your application in `app/models/merit/*`
---
# Defining badge rules
You may give badges to any resource on your application if some condition
holds. Badges may have levels, and may be temporary. Define rules on
`app/models/merit/badge_rules.rb`:
`grant_on` accepts:
* `'controller#action'` string (similar to Rails routes)
* `:badge` for badge name
* `:level` for badge level
* `:to` method name over target_object which obtains object to badge
* `:model_name` (string) define controller's name if it differs from
the model (like `RegistrationsController` for `User` model).
* `:multiple` (boolean) badge may be granted multiple times
* `:temporary` (boolean) if the receiver had the badge but the condition
doesn't hold anymore, remove it. `false` by default (badges are kept
forever).
* `&block`
* empty (always grants)
* a block which evaluates to boolean (recieves target object as parameter)
* a block with a hash composed of methods to run on the target object with
expected values
## Examples
```ruby
# app/models/merit/badge_rules.rb
grant_on 'comments#vote', :badge => 'relevant-commenter', :to => :user do |comment|
comment.votes.count == 5
end
grant_on ['users#create', 'users#update'], :badge => 'autobiographer', :temporary => true do |user|
user.name.present? && user.address.present?
end
```
```ruby
# Check granted badges
current_user.badges # Returns an array of badges
# Grant or remove manually
current_user.add_badge(badge.id)
current_user.rm_badge(badge.id)
```
---
# Defining point rules
Points are given to "meritable" resources on actions-triggered, either to the
action user or to the method(s) defined in the `:to` option. Define rules on
`app/models/merit/point_rules.rb`:
`score` accepts:
* `:on` action as string or array of strings (similar to Rails routes)
* `:to` method(s) to send to the target_object (who should be scored?)
* `&block`
* empty (always scores)
* a block which evaluates to boolean (recieves target object as parameter)
## Examples
```ruby
# app/models/merit/point_rules.rb
score 10, :to => :post_creator, :on => 'comments#create' do |comment|
comment.title.present?
end
score 20, :on => [
'comments#create',
'photos#create'
]
score 15, :on => 'reviews#create', :to => [:reviewer, :reviewed]
```
```ruby
# Check awarded points
current_user.points # Returns an integer
# Score manually
current_user.add_points(20, 'Optional log message')
current_user.substract_points(10)
```
---
# Defining rank rules
5 stars is a common ranking use case. They are not given at specified actions
like badges, you should define a cron job to test if ranks are to be granted.
Define rules on `app/models/merit/rank_rules.rb`:
`set_rank` accepts:
* `:level` ranking level (greater is better)
* `:to` model or scope to check if new rankings apply
* `:level_name` attribute name (default is empty and results in
'`level`' attribute, if set it's appended like
'`level_#{level_name}`')
Check for rules on a rake task executed in background like:
```ruby
task :cron => :environment do
Merit::RankRules.new.check_rank_rules
end
```
## Examples
```ruby
set_rank :level => 2, :to => Commiter.active do |commiter|
commiter.branches > 1 && commiter.followers >= 10
end
set_rank :level => 3, :to => Commiter.active do |commiter|
commiter.branches > 2 && commiter.followers >= 20
end
```
# To-do list
* Improve model_additions with http://blog.8thlight.com/josh-cheek/2012/02/03/modules-called-they-want-their-integrity-back.html
* Should namespace Badge, BadgesSash and Sash into Merit module.