here_document.rb

module ApplicationHelper
  def google_tag_manager_head
    return unless Rails.env.production?
    <<-HTML.html_safe
<!-- Google Tag Manager -->
<script>(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':
new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],
j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src=
'https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);
})(window,document,'script','dataLayer','GTM-WHX4V4D');</script>
<!-- End Google Tag Manager -->
    HTML
  end

  def google_tag_manager_body
    return unless Rails.env.production?
    html = <<-SQL
<!-- Google Tag Manager (noscript) -->
<noscript><iframe src="https://www.googletagmanager.com/ns.html?id=GTM-WHX4V4D"
height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript>
<!-- End Google Tag Manager (noscript) -->
    SQL
    html.html_safe
  end

  def google_tag_manager_body2
    return unless Rails.env.production?
    html = <<-HTML
<!-- Google Tag Manager (noscript) -->
<noscript><iframe src="https://www.googletagmanager.com/ns.html?id=GTM-WHX4V4D"
height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript>
<!-- End Google Tag Manager (noscript) -->
    HTML
    html.html_safe
  end
end

more_here_documents.rb

sql = <<-SQL
SELECT * FROM employees
SQL

sql = <<-EOS
SELECT * FROM employees
EOS

html = <<-HTML
<div>
  <a href="くりにっき">http://sue445.hatenablog.com/</a>
</div>
HTML

html = <<-EOS
<div>
  <a href="くりにっき">http://sue445.hatenablog.com/</a>
</div>
EOS

js = <<-JAVASCRIPT
var sum = 0;
for(var i = 0; i < 10; i++){
  sum += i;
}
JAVASCRIPT

js = <<-EOS
var sum = 0;
for(var i = 0; i < 10; i++){
  sum += i;
}
EOS

json = <<-JSON
{
  title: "Dokidoki Precure",
  menbers: ["Cure Heart", "Cure Diamond", "Cure Rosetta", "Cure Sword"],
}
JSON

json = <<-EOS
{
  title: "Dokidoki Precure",
  menbers: ["Cure Heart", "Cure Diamond", "Cure Rosetta", "Cure Sword"],
}
EOS

ruby = <<-RUBY
(1 .. 10).inject(0){|sum, n| sum += n }
RUBY

ruby = <<-EOS
(1 .. 10).inject(0){|sum, n| sum += n }
EOS

java = <<-JAVA
int sum = 0;
for(int i = 0; i < 10; i++){
  sum += i;
}
JAVA

java = <<-GROOVY
int sum = 0
for(int i = 0; i < 10; i++){
  sum += i
}
GROOVY