Skip to content
This repository


Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP

A rails 3 comments engine

tree: abfac87c75

Fetching latest commit…

Cannot retrieve the latest commit at this time




Opinio is an engine used to add comments behaviour to your application. The engine is designed to work only with *Rails 3*


Simply add the following line to your Gemfile:

gem "opinio"

and run:



Rdocs here:


Opinio provides generators to facilitate it's usage. The most common way to quickly get Opinio working is:

rails g opinio:install comment

This will generate the Comment model, migration and also generate the opinio initializer for customization of the engine. A `opinio_model` will be added on the `routes.rb`. This method adds the default urls for the model that will acts as the comment

In order to add the comments functionallity to a model, you use the opinio_subjectum method

class Post < ActiveRecord::Base

On the `routes.rb` you should simply add an `opinio` for your resource that will have comments

resources :posts do

If you want to display the comments for the item outside of the resource, you can simply add this to your views:

<%= comments_for @post %>

And there you go, you can now comment in your post. Aditional options can be found on the RDocs

Alternatively you can render just the comments or just the form like this:

<%= render_comments @post %>
<%= render_comments_form @post %>



Of course you will want to customize how the comments are displayed or any other customization to the view. To generate the view files on your application, run:

rails g opinio:views

And you can customize all the views used by the engine.


Pretty Urls

Often times you will want the engine to show the index of comments for a specific item without having to pass :commentable_type or :commentable_id.

In order to do that, opinio provides a method to *ActionController::Base*:

opinio_identifier do |params|
  next Review.find(params[:review_id]) if params[:review_id]
  next Product.find(params[:product_id]) if params[:product_id]

Note: you use next instead of return because it is a proc that will be executed later on, and you cannot return on procs

Basically on this method you receive the params variable and you tell the engine, who owns the comments from that page. This allows you to use routes like:


Without passing those 2 parameters. I suggest you put this method on the ApplicationController

Customize destroy conditions

By default, anyone can destroy any comment in the engine. We don't want that. To setup a custom destroy condition we can use the methods provided by opinio in our controllers. For instance, if our opinio model is called 'comment' it would be like this:

comment_destroy_conditions do |comment|
  comment.owner == current_user

This would make users only be able to remove their own comments. Another example would be using the CanCan:

comment_destroy_conditions do |comment|
  authorize :destroy, comment

You get the picture, you're inside your controller's methods on that block so you can call anything your normal controllers call on actions.


If you want to help in any way with Opinio please message me or fork the project, make the changes and send me a pull request. For issues please use the github issues tracker

Remember this engine is still in development :)


* Haml views
* Better controller overriding (coding and documentation)
* Support for deeper levels of replies
* Refactor the `comments_for` helper
* Extract documentation to wiki
Something went wrong with that request. Please try again.