How to set up a basic premailer test task

test_controller.rb

class TestController < ApplicationController
  def email
    prepare_email(params[:type])
    
    PremailerRails::Hook.delivering_email(@mail)
    if params[:part] == 'css'
      render :template => @html_template, :layout => 'email'
    elsif params[:part] == 'html'
      render :text => @mail.html_part.body
    else
      plain = @mail.parts.find {|p| p.content_type =~ /text\/plain/ }
      render :text => @mail.text_part.body
    end
  end
protected
  def prepare_email(type)
    self.send "prepare_#{type.to_s}".to_sym
  end
  
  def prepare_welcome
    @user = user
    @url  = "http://example.com/login"
    @html_template = 'user_mailer/welcome.html.erb'
    @mail = UserMailer.welcome_email(@user)
  end

URLs

This code is vaguely based on the action mailer rails guide example. Now try:

/test/email?type=welcome&part=text
This is the plain text part of the email

/test/email?type=welcome&part=css
This is the html part, before premailing, standard css, easier to debug

/test/email?type=welcome&part=html
This is the premailed part, there are sometimes subtle differences.