Question

The author, Michael Hartl, says:

Here the rule:

get "static_pages/home"

maps requests for the URI /static_pages/home to the home action in the StaticPages controller.

How? The type of request is given, the url is given, but where is the mapping to a controller and action? My tests all pass, though.

I also tried deleting all the actions in the StaticPagesController, which just looks like this:

class StaticPagesController < ApplicationController
  def home
  end

  def about
  end

  def help
  end

  def contact
  end
end

…and my tests still pass, which is puzzling. No, I deleted all my actions like this:

class StaticPagesController < ApplicationController
end

The 2nd edition of the book(online) is really frustrating. Specifically, the section about making changes to the Guardfile is impossible to follow. For instance, if I instruct you to edit this file:

blah blah blah
dog dog dog
beetle beetle beetle
jump jump jump

and make these changes:

blah blah blah
.
.
.
go go go
.
.
.
jump jump jump

…would you have any idea where the line ‘go go go’ should be in the code?

And the hint for exercise 3.5-1 is flat out wrong. If the author would put up a comment section at the end of every chapter, the rails community could self-edit the book.

Tests:

require 'spec_helper'

describe "StaticPages" do
  let(:base_title) { "Ruby on Rails Tutorial Sample App" }

  describe "Home page" do
    it "should have the h1 'Sample App'" do
      visit '/static_pages/home'
      page.should have_selector('h1', :text => 'Sample App')
    end

    it "should have the title 'Home'" do
      visit "/static_pages/home"
      page.should have_selector(
            'title', 
            :text => "#{base_title} | Home")
    end

  end

  describe 'Help page' do
    it "should have the h1 'Help'" do
      visit "/static_pages/help"
      page.should have_selector('h1', :text => 'Help')
    end

    it "should have the title 'Help'" do
      visit '/static_pages/help'
      page.should have_selector(
            'title',
            :text => "#{base_title} | Help")
    end

  end

  describe 'About page' do
    it "should have the h1 'About'" do
      visit '/static_pages/about'
      page.should have_selector('h1', :text => 'About')
    end

    it "should have the title 'About'" do
      visit '/static_pages/about' 
      page.should have_selector(
            'title',
            :text => "#{base_title} | About")
    end
  end

  describe 'Contact page' do
    it "should have the h1 'Contact'" do
      visit '/static_pages/contact'
      page.should have_selector('h1', :text => 'Contact')
    end

    it "should have the title 'Contact'" do
      visit '/static_pages/contact'
      page.should have_selector(
            'title', 
            :text => "#{base_title} | Contact")
    end
  end

end

Answer 1

I found an answer to this conundrum. First of all, this is a rails ‘problem’ not an rspec problem; if I add a route to routes.rb such as:

get "static_pages/dog"

…and then enter the url

http://localhost:3000/static_pages/dog 

in my browser, rails complains:

Unknown action

The action ‘dog’ could not be found for StaticPagesController

Then if I add the dog action to the controller, then create a view,
everything works fine and dandy.

But if I then delete the dog action, and then use the same url,

http://localhost:3000/static_pages/dog

in my browser, this time I get a different result–instead of getting an error the view displays.

As it turns out, that inconsistent behavior is a rails ‘feature’ called default rendering, explained here:

http://guides.rubyonrails.org/layouts_and_rendering.html#rendering-by-default-convention-over-configuration-in-action

According to the docs, all that’s needed to render a page is a route and a view–the action is optional.