has_slug¶ ↑

Description¶ ↑

has_slug is a plugin that add’s slugging capabilities to ActiveRecord models. It allows you to create SEO friendly URL’s that will work the same as the numeric defaults Rails provides you.

Using has_slug, you can make this:

http://example.com/articles/1

Look like this:

http://example.com/articles/1-first-post

Or even better:

http://example.com/articles/first-post

has_slug is inspired by friendly_id (github.com/norman/friendly_id/tree/master), but instead of adding a new table for the slugs it uses a single column per model.

Why?¶ ↑

• Text-based id’s look better

• They make URL’s easier to remember.

• They give no hint about the number of records in your database.

• They are better for search engine optimization.

But …¶ ↑

• It can be tricky to ensure they’re always unique.

• They can change, breaking your URL’s and your SEO.

• They can conflict with your application’s namespace.

has_slug takes care of creating unique slugs by using a counter. The first time a slug is generated for “Some Title”, it will become “some-title”. The second time this is done, it will use the slug “some-title_2”.

has_slug DOES NOT take care of changing slugs! If you need to care of this, either use the friendly_id plugin, which DOES take care of this, or use a custom solution.

has_slug also doesn’t take care of the namespace conflicts (a slug named ‘new’ for instance), you could use the following technique if this is required: henrik.nyh.se/2008/10/validating-slugs-against-existing-routes-in-rails

Usage¶ ↑

Typical usage (with slug column)¶ ↑

Blog posts have a distinct, but not necessarily unique title stored in a column in the database. If we add a slug column to the posts table, we can use has_slug to generate slugs automatically.

class Post < ActiveRecord::Base
  has_slug :title
end

We can then use the standard url helpers to generate a SEO friendly URL:

@post_1 = Post.create(:title       => 'First Post',
                      :description => 'Description ...')

@post_2 = Post.create(:title       => 'First Post',
                      :description => 'Description ...')

url_for(@post_1)
# => http://example.com/posts/first-post

url_for(@post_2)
# => http://example.com/posts/first-post_2

And use the standard finder to find the corresponding post:

@post = Post.find('first-post')

You can also use the found_by_slug? method to find out if the record was found by the slug. You could use this to redirect to the URL with the slug for SEO purposes.

redirect_to(@post, :status => 301) unless @post.found_by_slug?

Typical usage (without slug column)¶ ↑

We can also use has_slug without adding the slug column. If we do this, the id of the record is prepended to the slug.

@post = Post.find(1)

url_for(@post)
# => http://example.com/posts/1-first-post

Scoped usage¶ ↑

Restaurants belong to a city. They have a unique name, but only in the city they are in. If we add a slug column to the restaurants table, we can use has_slug to generate scoped slugs automatically.

class Restaurant < ActiveRecord::Base
  belongs_to :city

  has_slug :name, :scope => :city
end

We can then use the standard url helpers to generate a SEO friendly URL:

@restaurant_1 = Restaurant.create(:name => 'Da Marco',
                                  :city => City.find('new-york'))

@restaurant_2 = Restaurant.create(:name => 'Da Marco',
                                  :city => City.find('san-fransisco'))

url_for(@restaurant_1.city, @restaurant)
# => http://example.com/cities/new-york/restaurants/da-marco

url_for(@restaurant_2.city, @restaurant)
# => http://example.com/cities/san-fransisco/restaurants/da-marco

Authors¶ ↑

• Tom-Eric Gerritsen (tomeric@i76.nl)