ror41Tagging is a way to give a keyword and search by that particular keyword. In Rails “acts-as-taggable-on” is one of the popular gem for tagging. With ‘acts_as_taggable_on’, you can tag a single model on several contexts, such as skills, interests, and awards

Below is an example to describe how to implement it in a Rails application:

    Step#1

  • Add the gem to your Gemfile:
  • gem ‘acts-as-taggable-on'
  • Then run the bundle
  • bundle install

    Step#2

  • Run the generator command
  • rails g acts_as_taggable_on:migration
  • Run the migration file
  • rake db:migrate

    This migration will create two tables in the database: tags and taggings.
    Step#3
    Now you have to modify your model where you want to implement tagging.
    For example, we like to implement the tagging on Post model.

  • Add the following codes to the “Post” model to have acts_as_taggable and also add a “tag_list” field to the attr_accessible list.
  • attr_accessible :content, :name, :tag_list
    acts_as_taggable

    Step#4

  • Add a new field to your post form.
  • <%= f.label :tag_list, "Tags (separated by commas)" %>
    <%= f.text_field :tag_list %>

    Step#5

  • Add the following codes, if you want to show the tags for the tagged posts in the listing page:
  • <% @posts.each do |post| %>
    <h2><%= link_to post.name, post %></h2>
    <%= simple_format post.content %>
    <p>
    Tags: <%= raw post.tag_list.map { |t| link_to t, tag_path(t) }.join(', ') %>
    </p>
    <% end %>

    Step#6

  • Modify your route file to get the tags
  • get 'tags/:tag', to: 'posts#index', as: :tag

    Step#7

  • Modify your controller:
  • class PostsController < ApplicationController
    def index
    if params[:tag]
    @posts = Post.tagged_with(params[:tag])
    else
    @posts = Post.all
    end
    end
    end
    

Voila! You have done it.