Mailers

Lesli::ApplicationLesliMailer is the shared base for mailers that use Lesli's email templates and URL-building conventions.

module MyEngine
  class NotificationMailer < Lesli::ApplicationLesliMailer
    default from: "[email protected]"
  end
end

The base mailer reads its default template path from Lesli.config.mailer[:templates], which defaults to lesli_assets/emails.

Configure URL Generation

build_url uses Action Mailer's default_url_options. Configure a host and protocol for each environment that sends email:

# config/environments/production.rb
config.action_mailer.default_url_options = {
  host: "app.example.com",
  protocol: "https"
}

For local development with a nonstandard port:

config.action_mailer.default_url_options = {
  host: "localhost",
  port: 3000,
  protocol: "http"
}

Build application URLs inside the mailer with an optional query hash:

url = build_url("/password/edit", reset_password_token: token)

Always pass a path beginning with /.

Send a Templated Email

Subclass methods call the protected email helper with template parameters, recipient, subject, and template name:

module MyEngine
  class NotificationMailer < Lesli::ApplicationLesliMailer
    default from: "[email protected]"

    def assignment(user, ticket)
      email(
        {
          user: user,
          ticket: ticket,
          ticket_url: build_url("/support/tickets/#{ticket.id}")
        },
        to: user.email,
        subject: "Ticket assigned",
        template_name: "tickets/assignment"
      )
    end
  end
end

The helper exposes the parameter hash to the template as @params. It also builds @app, including the application URL and company information when params[:user] is a Lesli::User.

Deliver the message with standard Action Mailer APIs:

MyEngine::NotificationMailer.assignment(user, ticket).deliver_later

Template Location

With the default configuration, the example looks for a template below:

app/views/lesli_assets/emails/tickets/assignment.html.erb

Override the shared template root in the Lesli initializer when the application provides a different template collection:

Lesli.configure do |config|
  config.mailer = config.mailer.merge(
    templates: "my_engine/emails"
  )
end

The template would then live below app/views/my_engine/emails/.

Recipient Helpers

The base mailer includes protected helpers that format arrays of users or contact hashes with display names:

recipients = build_recipients_from_users(users)
contacts = build_recipients_from_contacts(
  [{ name: "Support", email: "[email protected]" }]
)

Both helpers expect arrays. They return nil for other input types.

Development Delivery

Use the local email-preview setup from the installation guide to inspect messages without sending them to a real provider.

For production, configure the host application's Action Mailer delivery method and provider credentials separately. Lesli::ApplicationLesliMailer does not configure SMTP or an external email service.