1 files changed, 72 insertions, 0 deletions
diff --git a/actionmailer/lib/action_mailer/mail_helper.rb b/actionmailer/lib/action_mailer/mail_helper.rb
new file mode 100644
index 0000000000..e7bed41f8d
--- /dev/null
+++ b/actionmailer/lib/action_mailer/mail_helper.rb
@@ -0,0 +1,72 @@
+# frozen_string_literal: true
+
+module ActionMailer
+  # Provides helper methods for ActionMailer::Base that can be used for easily
+  # formatting messages, accessing mailer or message instances, and the
+  # attachments list.
+  module MailHelper
+    # Take the text and format it, indented two spaces for each line, and
+    # wrapped at 72 columns:
+    #
+    #   text = <<-TEXT
+    #     This is
+    #     the      paragraph.
+    #
+    #     * item1 * item2
+    #   TEXT
+    #
+    #   block_format text
+    #   # => "  This is the paragraph.\n\n  * item1\n  * item2\n"
+    def block_format(text)
+      formatted = text.split(/\n\r?\n/).collect { |paragraph|
+        format_paragraph(paragraph)
+      }.join("\n\n")
+
+      # Make list points stand on their own line
+      formatted.gsub!(/[ ]*([*]+) ([^*]*)/) { "  #{$1} #{$2.strip}\n" }
+      formatted.gsub!(/[ ]*([#]+) ([^#]*)/) { "  #{$1} #{$2.strip}\n" }
+
+      formatted
+    end
+
+    # Access the mailer instance.
+    def mailer
+      @_controller
+    end
+
+    # Access the message instance.
+    def message
+      @_message
+    end
+
+    # Access the message attachments list.
+    def attachments
+      mailer.attachments
+    end
+
+    # Returns +text+ wrapped at +len+ columns and indented +indent+ spaces.
+    # By default column length +len+ equals 72 characters and indent
+    # +indent+ equal two spaces.
+    #
+    #   my_text = 'Here is a sample text with more than 40 characters'
+    #
+    #   format_paragraph(my_text, 25, 4)
+    #   # => "    Here is a sample text with\n    more than 40 characters"
+    def format_paragraph(text, len = 72, indent = 2)
+      sentences = [[]]
+
+      text.split.each do |word|
+        if sentences.first.present? && (sentences.last + [word]).join(" ").length > len
+          sentences << [word]
+        else
+          sentences.last << word
+        end
+      end
+
+      indentation = " " * indent
+      sentences.map! { |sentence|
+        "#{indentation}#{sentence.join(' ')}"
+      }.join "\n"
+    end
+  end
+end