helpers-layouts-mailer

Helpers, Layouts, and Partials Homework

We will be working off of the solutions for 99 Cats II: Auth for today's homework assignment. Download the zipped solution, extract, bundle install and bundle exec rake db:setup to set it up.

Topic 1: View Helpers

Isn't it pesky to have to rewrite the code for the form_authenticity_token field over and over? Let's abstract it into a simple helper method that we can use across our views.

Open up your helpers/application_helper.rb file and write a new method called auth_token. As a refresher, your auth token code in your views should look something like this:

<input
  type="hidden"
  name="authenticity_token"
  value='<%= form_authenticity_token %>'
/>

Let's put this code in our new auth_token method, but with a few changes. First of all, we'll need to wrap the input tag in a string and call #html_safe on it. Otherwise, our auth_token method will output the string literal for our input tag. Secondly, now that our input tag is little more than a string in Ruby-land, we shouldn't interpolate the actual form_authenticity_token using erb tags. Instead, just interpolate form_authenticity_token using the string interpolation syntax we know and love (#{}).

Sweet! Looking good? Now go through your app and replace all of the form_authenticity_token input fields with calls to your snazzy new method, <%= auth_token %>, to dry up your code and simplify your life.

Topic 2: Layouts

We've been using layouts in Rails every day without even knowing it! Let's check out our application.html.erb file. In particular, notice the <%= yield %> tag in the middle of the layout. This will yield in the content for whatever page we're on, whether that's the cats index or new user form.

Now, let's say we want to add a footer on our application.html.erb layout. We want our footer to display a paragraph describing our site on every page of our site. In addition, we want it to display a line describing the particular page we are on. This is a perfect time to use Rails's content_for method.

First, create a footer section in your application.html.erb at the end of the body tag, and write in a paragraph describing your site. Verify that this shows up on every page as you navigate around in localhost.

Next, let's add a second yield tag to insert the custom footer content within the new footer section. It should look something like this:

<footer>
  This is our 99 Cats site. Please feel free to browse!

  <%= yield :footer %>
</footer>

Now, time to add some page specific content. Go through each of your views, and add a line specific to that page. It should look something like this:

<p>Other content for the cats index goes here</p>

<% content_for :footer do %>
  <p>This is the cats index page.</p>
<% end %>

Finished? Navigate around your site in localhost. Make sure that the main body of each page appears in the main yield section of the layout, and that your footer-specific content appears in the footer.

Topic 3: Action Mailer

1. Create a user mailer to welcome new users to your account. The bundle exec rails generate mailer UserMailer command will create a new mailer class file with some default code in app/mailers/user_mailer.rb.

class UserMailer < ApplicationMailer
  default from: '[email protected]'
end

2. Implement a #welcome_email method that will e-mail a user from [email protected].

Need a hint? Refer back to the mailer readings.

class UserMailer < ApplicationMailer
  default from: '[email protected]'

  def welcome_email(user)
    # your code here
  end
end

3. Next, write the content for the e-mail welcoming the user to the site. Create a welcome_email.html.erb file in app/views/user_mailer/ and fill it in.

In addition to the .html.erb file, make a text-only version in welcome_email.txt.erb. Remember - omitting a text version of your email could make many filters interpret your email as spam!

4. When a user signs up for your app, send them the welcome e-mail. Where should that code live within our existing UsersController? Implement the code.

Remember - we need a few things. We must call our new welcome_email method, which returns a message, and call deliver_now on that message to actually send it:

msg = UserMailer.welcome_email(@user)
msg.deliver_now

5. Test it out! Set up the letter_opener gem so that you can try out your code on localhost:3000. The sent message should pop up in the browser if all went according to plan. Congrats! You've ActionMailed!

# Gemfile
gem 'letter_opener', group: :development

# config/environments/development.rb
config.action_mailer.delivery_method = :letter_opener