Hanami offers a helpful way to present numbers via #format_number, a private method available only in views.

Usage

module Web
  module Views
    module Books
      class Show
        include Web::View
        def download_count
          format_number book.download_count
        end
      end
    end
  end
end

<span><%= download_count %></span>

<span>1,000,000</span>

Precision

The default precision is of 2, but we can specify a different value with the homonym option.

format_number(Math::PI)               # => "3.14"
format_number(Math::PI, precision: 6) # => "3.141592"

Delimiter

The default thousands delimiter is ,. We can use :delimiter for a different char.

format_number(1_000_000)                 # => "1,000,000"
format_number(1_000_000, delimiter: '.') # => "1.000.000"

Separator

The default separator is .. We can use :separator for a different char.

format_number(1.23)                 # => "1.23"
format_number(1.23, separator: ',') # => "1,23"