Ruby-on-rails – Overriding named routes provided by Rails 3 Engines

rails-enginesroutesruby-on-railsruby-on-rails-3

I am working on a Ruby on Rails 3(.0) application that uses a Rails engine. However, in my local application, I want to override one of the routes provided by the Rails engine.

From the engine config/routes.rb:

match 'their_named_route' => 'controller#action', :as => 'the_route'

From my application config/routes.rb:

match 'my_named_route' => 'controller#action', :as => 'the_route'

However, when I inspect the routes, both seem to be active (and their route appears to "win", at least within the engine controllers)

$ rake routes
the_route  /my_named_route(.:format)    {:controller=>"controller", :action=>"action"}
the_route  /their_named_route(.:format) {:controller=>"controller", :action=>"action"}

Is there a good way to force my local application's named route to take priority?

Best Answer

I got around this by moving my engine's routes from config/routes.rb to a class method in the engine class itself:

module MyEngine
  class Engine < Rails::Engine
    def self.routes
      MyRailsApp::Application.routes.draw do
        resources :products
      end
    end
  end
end

and then in the base app's routes file:

MyRailsApp::Application.routes.draw do
  # Routes for base app including the ones overriding MyEngine::Engine.

  MyEngine::Engine.routes
end

I can then happily override any routes in the base app with those in the engine.

Note that the overriding routes need to be defined before the overridden routes since the earlier defined routes take precedence over later ones.

Related Solutions

Ruby-on-rails – Rails: How to rename a database column in a Ruby on Rails migration

rename_column :table, :old_column, :new_column

You'll probably want to create a separate migration to do this. (Rename FixColumnName as you will.):

script/generate migration FixColumnName
# creates  db/migrate/xxxxxxxxxx_fix_column_name.rb

Then edit the migration to do your will:

# db/migrate/xxxxxxxxxx_fix_column_name.rb
class FixColumnName < ActiveRecord::Migration
  def self.up
    rename_column :table_name, :old_column, :new_column
  end

  def self.down
    # rename back if you need or do something else or do nothing
  end
end

For Rails 3.1 use:

While, the up and down methods still apply, Rails 3.1 receives a change method that "knows how to migrate your database and reverse it when the migration is rolled back without the need to write a separate down method".

See "Active Record Migrations" for more information.

rails g migration FixColumnName

class FixColumnName < ActiveRecord::Migration
  def change
    rename_column :table_name, :old_column, :new_column
  end
end

If you happen to have a whole bunch of columns to rename, or something that would have required repeating the table name over and over again:

rename_column :table_name, :old_column1, :new_column1
rename_column :table_name, :old_column2, :new_column2
...

You could use change_table to keep things a little neater:

class FixColumnNames < ActiveRecord::Migration
  def change
    change_table :table_name do |t|
      t.rename :old_column1, :new_column1
      t.rename :old_column2, :new_column2
      ...
    end
  end
end

Then just db:migrate as usual or however you go about your business.

For Rails 4:

While creating a Migration for renaming a column, Rails 4 generates a change method instead of up and down as mentioned in the above section. The generated change method is:

$ > rails g migration ChangeColumnName

which will create a migration file similar to:

class ChangeColumnName < ActiveRecord::Migration
  def change
    rename_column :table_name, :old_column, :new_column
  end
end

Ruby-on-rails – Listing ‘rake routes’ for a mountable Rails 3.1 engine

In case people are missing it in the comments, as of Rails 3.2.2, you can now use

$ rake app:routes

Best Answer

Related Solutions

Ruby-on-rails – Rails: How to rename a database column in a Ruby on Rails migration

Ruby-on-rails – Listing ‘rake routes’ for a mountable Rails 3.1 engine

Related Topic