How to display data from a variable in the subject and body of the letter?

Question

Ruby on Rails

It is necessary to display data from a variable in a certain place in the text of the letter. The texts of the letters are stored in the database. Added @tmp variable in Mailer controller. In the text of the letter I add <%= @tmp %>, but it doesn't work, it displays - <%= @tmp %>. Tried #{@tmp}, same result.

Answer 1

Where a letter template from the database is substituted into the body of the letter, you need to use the ERB processor, while passing the current context (binding) into it

@tmp = 'Some value'
email_body = ERB.new(mail_template_from_database).result(binding)

mail(to: user_email,  body: email_body,   content_type: "text/html",   subject: "Email subject")

Answer 2

If the template engine is ERB, then the syntax is correct <%= @tmp %>(they forgot the % before the closing bracket).