Working with ERB can get the job done, but there are fantasic alternatives to achieve the same result with much less code.

Input HAML. From their website:

Haml (HTML abstraction markup language) is based on one primary principle: markup should be beautiful. It’s not just beauty for beauty’s sake either; Haml accelerates and simplifies template creation down to veritable haiku.

At BNB, we use HAML’s indentation-based markup to manage the nesting of our HTML nodes for us. No more managing of closing </div> tags everywhere!

Install haml-rails

First, open your Gemfile and add both the haml-rails and the html2haml gems:

Gemfile

# Use Active Storage variant
# gem 'image_processing', '~> 1.2'

# Reduces boot times through caching; required in config/boot.rb
gem 'bootsnap', '>= 1.4.4', require: false

gem "haml-rails", "~> 2.0"
gem "html2haml"

Then bundle your gemfile with

dip bundle i

Convert .erb Views

Haml-rails comes with an amazing command to convert all existing views from .erb views into .haml. You can do so by running:

dip rails haml:erb2haml

You will see an output similar to:

Starting bnb-library_postgres_1 ... done
Generating HAML for app/views/books/edit.html.erb...
Generating HAML for app/views/books/new.html.erb...
Generating HAML for app/views/books/index.html.erb...
Generating HAML for app/views/books/show.html.erb...
Generating HAML for app/views/books/_form.html.erb...
Generating HAML for app/views/publishers/edit.html.erb...
Generating HAML for app/views/publishers/new.html.erb...
Generating HAML for app/views/publishers/index.html.erb...
Generating HAML for app/views/publishers/show.html.erb...
Generating HAML for app/views/publishers/_form.html.erb...
Generating HAML for app/views/layouts/mailer.text.erb...
Generating HAML for app/views/layouts/mailer.html.erb...
Generating HAML for app/views/layouts/application.html.erb...
Generating HAML for app/views/reviews/edit.html.erb...
Generating HAML for app/views/reviews/new.html.erb...
Generating HAML for app/views/reviews/index.html.erb...
Generating HAML for app/views/reviews/show.html.erb...
Generating HAML for app/views/reviews/_form.html.erb...
-------------------------------------------------------------
HAML generated for the following files:
        app/views/books/edit.html.erb
        app/views/books/new.html.erb
        app/views/books/index.html.erb
        app/views/books/show.html.erb
        app/views/books/_form.html.erb
        app/views/publishers/edit.html.erb
        app/views/publishers/new.html.erb
        app/views/publishers/index.html.erb
        app/views/publishers/show.html.erb
        app/views/publishers/_form.html.erb
        app/views/layouts/mailer.text.erb
        app/views/layouts/mailer.html.erb
        app/views/layouts/application.html.erb
        app/views/reviews/edit.html.erb
        app/views/reviews/new.html.erb
        app/views/reviews/index.html.erb
        app/views/reviews/show.html.erb
        app/views/reviews/_form.html.erb
-------------------------------------------------------------
Would you like to delete the original .erb files? (This is not recommended unless you are under version control.) (y/n)

To which you can respond ‘y’, as we don’t want to keep duplicates of the now converted files.

And it will respond with

# y

Deleting original .erb files.
-------------------------------------------------------------
Task complete!
No .erb files found. Task will now exit.

Great work, you have converted your views!

After you do this make sure to stop your server, dip down and then dip up.

Let’s look at a view to get a feel for what we will be working with. Open app/views/books/index.html.haml

app/views/books/index.html.haml

%p#notice= notice
%h1 Books
%table
  %thead
    %tr
      %th Title
      %th Description
      %th Price
      %th{:colspan => "3"}
  %tbody
    - @books.each do |book|
      %tr
        %td= book.title
        %td= book.description
        %td= book.price
        %td= link_to 'Show', book
        %td= link_to 'Edit', edit_book_path(book)
        %td= link_to 'Destroy', book, method: :delete, data: { confirm: 'Are you sure?' }
%br/
= link_to 'New Book', new_book_path

See that the file name has changed from .erb to .haml. We are no longer using closing tags to specify parent and children elements, instead we now use nesting. Be aware, spacing and indentation matters!