How to use the command 'rails routes' (with examples)

Rails is a popular web application development framework written in Ruby. The rails routes command is used to list all the routes defined in a Rails application. It provides a detailed overview of the routes and their corresponding URL paths, HTTP verbs, and controller/action mappings.

Use case 1: List all routes

Code:

rails routes

Motivation:

• To get an overview of all the routes defined in a Rails application, including their URL paths, HTTP verbs, and controller/action mappings.

Explanation:

• The command rails routes is executed without any additional arguments. It displays all the routes defined in the application.

Example output:

Prefix Verb URI Pattern           Controller#Action
posts GET  /posts(.:format)      posts#index
      POST /posts(.:format)      posts#create
...

Use case 2: List all routes in an expanded format

Code:

rails routes --expanded

Motivation:

• To get more detailed information about the routes, including constraints, helpers, and middleware.

Explanation:

• The --expanded option is added to the rails routes command. It provides a more detailed view of the routes, including constraints, helpers, and middleware.

Example output:

Prefix Verb URI Pattern           Controller#Action
posts GET  /posts(.:format)      posts#index {:format=>:json}
      POST /posts(.:format)      posts#create {:format=>:json}
...

Use case 3: List routes partially matching URL helper method name, HTTP verb, or URL path

Code:

rails routes -g posts_path|GET|/posts

Motivation:

• To filter the routes and list only the ones that partially match a specific URL helper method name (posts_path), HTTP verb (GET), or URL path (/posts).

Explanation:

• The -g (or --grep) option is used along with the criteria for filtering the routes. In this example, the routes will be filtered to include only the ones that either have a URL helper method name containing posts_path, or an HTTP verb matching GET, or a URL path matching /posts.

Example output:

Prefix Verb URI Pattern           Controller#Action
posts GET  /posts(.:format)      posts#index

Use case 4: List routes that map to a specified controller

Code:

rails routes -c posts|Posts|Blogs::PostsController

Motivation:

• To find the routes that are mapped to a specific controller in the Rails application.

Explanation:

• The -c (or --controller) option is used to specify the controller name. In this example, the routes will be filtered to include only the ones that map to the PostsController, Posts, or Blogs::PostsController.

Example output:

Prefix Verb URI Pattern           Controller#Action
posts GET  /posts(.:format)      posts#index
      POST /posts(.:format)      posts#create
...

Conclusion:

The rails routes command is a powerful tool for listing and analyzing the routes in a Rails application. It helps in understanding the request/response flow and the controller/action mappings. By using various options and arguments, like --expanded, -g, and -c, it allows developers to filter and display specific routes based on their requirements. Whether you need a comprehensive overview of all the routes or want to narrow down the list based on specific criteria, the rails routes command provides the necessary information.