Chapter 2 - Routing

Question 1

The two Purposes of routing

Answer 1

• Recognizing incoming requests and mapping them to a corresponding controller action, along with any additional variable receptors
• Recognizing URL parameters in methods such as link_to and matching them up to a corresponding route so that proper HTML links can be generated

Question 2

The two Purposes of routing

Answer 2

It maps requests to controller action methods, and it enables the dynamic generation of URLs for you for use as arguments to methods like link_to and redirect_to.

Question 3

REST

Answer 3

representational state transfer (REST).

Question 4

Regular Routes

Answer 4

get ‘products/: id’ = > ‘products# show’

Question 5

Constraining Request Methods

Answer 5

As of Rails 4, it’s recommended to limit the HTTP method used to access a route. If you are using the match directive to define a route, you accomplish this by using the :via option:

match ‘products/: id’ = > ‘products# show’, via: :get

Question 6

segment keys

Answer 6

The URL pattern string can contain parameters (denoted with a colon), referred to as segment keys. In the following route declaration, :id is a segment key:

get ‘products/: id’ = > ‘products# show’

Question 7

Redirect method

Answer 7

get “/ foo”, to: redirect(‘/ bar’)

Question 8

Route Globbing

Answer 8

In some situations, you might want to grab one or more components of a route without having to match them one by one to specific positional parameters.

You define it by globbing the route with an asterisk.

get ‘items/ list/* specs’, controller: ‘items’, action: ‘list’

Question 9

Create Named Route

Answer 9

get ‘help’ = > ‘help# index’, as: ‘help’

In this example, Rails will generate methods called help_url and help_path in controller and view contexts, which you can use wherever Rails expects a URL or URL components:

link_to “Help”, help_path

And, of course, the usual recognition and generation rules are in effect. The pattern string consists of just the static string component “help”. Therefore, the path you’ll see in the hyperlink will be the following:

/help

Question 10

Create Named Route

Answer 10

get ‘help’ = > ‘help# index’, as: ‘help’

In this example, Rails will generate methods called help_url and help_path in controller and view contexts, which you can use wherever Rails expects a URL or URL components:

link_to “Help”, help_path

And, of course, the usual recognition and generation rules are in effect. The pattern string consists of just the static string component “help”. Therefore, the path you’ll see in the hyperlink will be the following:

/help

Question 11

name_path vs name_url

Answer 11

> > app.clients_path = > “/ clients”

> > app.clients_url = > “http:// www.example.com/ clients”

Question 12

Namespaces

Answer 12

namespace :auctions, :controller = > :auctions do
   get 'new' = > :new 
   get 'edit/: id' = > :edit
   post 'pause/: id' = > :pause 
end