README.textile

Path: README.textile
Last Update: Sun Mar 21 02:40:18 -0600 2010

h2. Overview.

A plugin for the Merb framework that allows you to send email from Merb application. It separates email composition and sending into micro MVC: you may have mail controllers that compose complex emails, emails have their own views and models (models use MailFactory library and non-persistable).

h2. Installation.

(sudo) gem install merb-mailer

It will install "mailfactory":mailfactory.rubyforge.org/ gem and "mime-types":mime-types.rubyforge.org/ that mailfactory depends on.

h2. Configuration.

In init.rb, include a dependency on ‘merb-mailer’.With versions of Merb earlier than 0.9.3 Merb::Mailer may raise a NameError when configuration is put into after_app_loads block. Put it to the very end of your init file and it should work. This problem does not exist in Git HEAD.

h3. Using SMTP.

<pre><code class="ruby">

  Merb::Mailer.config = {
    :host   => 'smtp.yourserver.com',
    :port   => '25',
    :user   => 'user',
    :pass   => 'pass',
    :auth   => :plain # :plain, :login, :cram_md5, the default is no auth
    :domain => "localhost.localdomain" # the HELO domain provided by the client to the server
  }

</code></pre>

h3. Using Gmail SMTP.

Configuration example for Gmail SMTP:

<pre><code class="ruby"> Merb::Mailer.config = {

  :host   => 'smtp.gmail.com',
  :port   => '587',
  :user   => 'user@gmail.com',
  :pass   => 'pass',
  :auth   => :plain

} </code></pre>

  • require the gem "smtptls"
  • Use :text option instead of :body when deliver.

<pre><code class="ruby"> m = Merb::Mailer.new :to => ‘foo@bar.com’,

                     :from    => 'bar@foo.com',
                     :subject => 'Welcome to whatever!',
                     :text    => partial(:sometemplate)

m.deliver! </code></pre>

h3. Using Sendmail.

  Merb::Mailer.config = {:sendmail_path => '/somewhere/odd'}
  Merb::Mailer.delivery_method = :sendmail

h2. Sending mail from controllers.

Merb mailer plugin has idea of separation of mailer logic from mailer templates to the point mailers in Merb have own tiny MVC architecture for emails. Your application controllers usually delegate email sending to mail controllers instead of doing it on their own.

To send your mail using mail controller you use send_mail method that takes mail controller class, action name, mail parameters and action parameters. params hash with action parameters mentioned above is accessible in mail controller‘s action.

<pre> <code class="ruby"> def send_activation_email(person)

        send_mail PeopleMailer, :activation, {
                :from => "no-reply@example.com",
                :to => person.email,
                :subject => "Please activate your account"
        }, {
                :name => person.name
        }

end </code> </pre>

Mail parameters you can specify:

  • :to
  • :from
  • :replyto
  • :subject
  • :body
  • :cc

Example of Merb controller: <pre> <code class="ruby"> class ProductDeliveryMailer < Merb::MailController

  def notify_on_delivery
          @delivery_info = params[:details]
                # you can access @delivery_info in rendered template
    render_mail
  end

end </code> </pre>

Mail templates are kept under app/views/mail controller name/template name just like with regular controllers. Content types in template name may be either text or html, like in app/mailers/views/user_mailer/hello.text.erb for the mailer controller above:

<pre> Hello <%= params[:name] %> </pre>

render_mail works similarly to render method. It takes either action as Symbol or Hash of template paths. Most of the times naming templates the same as your actions works so you can just use

<pre> <code class="ruby"> class ResourceShortageMailer < Merb::MailController

  def notify_on_disk_space_shortage
    render_mail
  end

end </code> </pre>

and it will render app/mailers/views/resource_shortage_mailer/notify_on_disk_space_shortage.text.erb.

If you need to specify template path explicitly, you can do it for both text and html:

<pre> <code class="ruby"> class ResourceShortageMailer < Merb::MailController

  def notify_on_disk_space_shortage
    render_mail :action => { :html => :hdd_space_shortage_detailed, :text => :hdd_space_shortage }
  end

end </code> </pre>

This will look for app/mailers/views/resource_shortage_mailer/hdd_space_shortage_detailed.html.erb for html and app/mailers/views/resource_shortage_mailer/hdd_space_shortage.text.erb for text.

See Merb::MailerMixin#render_mail documentation for more examples, this method has a lot of options how you can use it.

h2. Using Merb mailer to send emails outside of controllers.

There are two ways of sending email with merb-mailer: using mail controllers and using just Merb::Mailer. Here is example of using Merb::Mailer to deliver emails from model hook.

class Person

        include DataMapper::Resource

        after :create, :deliver_activation_notification

  protected

  def deliver_activation_notification
          body_string = <<-EOS
                  Please activate your account...
                EOS

          Merb::Mailer.new(
                  :from    => "no-reply@webapp.com",
                        :to      => self.email,
                        :subject => "Activate your account",
                        :body    => body_string
                ).deliver!
  end

end

In this example we deliver signup activation email from model hook. Keep in mind that Merb::Mailer is a thin wrapper around MailFactory that provides several ways of sending emails. You can access plain text email body with text method of mailer and html body with html method, respectively.

h2. Testing mailers.

A word of warning: merb-mailer does not raise exceptions when your template is not found. So if nothing gets rendered, check merb test environment log to make sure you have no warnings. If it is considered a bug, file a ticket to LightHouse.

Make sure you use test sending method so emails won‘t be sent on each tests run. Add this line to your test file:

<pre> <code class="ruby"> Merb::Mailer.delivery_method = :test_send </code> </pre>

Here is an example of helper to test mailers themselves: <pre> <code class="ruby"> def describe_mail(mailer, template, &block)

  describe "/#{mailer.to_s.downcase}/#{template}" do
    before :each do
      @mailer_class, @template = mailer, template
      @assigns = {}
    end

    def deliver(send_params={}, mail_params={})
      mail_params = {:from => "from@example.com", :to => "to@example.com", :subject => "Please activate your account"}.merge(mail_params)
      @mailer_class.new(send_params).dispatch_and_deliver @template.to_sym, mail_params
      @mail = Merb::Mailer.deliveries.last
    end

    instance_eval &block
  end

end </code> </pre>

Mailer controller specs may look like this then: <pre> <code class="ruby"> require File.join(File.dirname(FILE),’..’,’spec_helper’)

describe_mail UserMailer, :hello do

  it "sends activation" do
    deliver :name => "Jamie"
    @mail.text.should == "Please activate your account, Jamie"
  end

end </code> </pre>

Most of mail controller specs verify delivered email headers like to, subject or body. To access deliveries you use Merb::Mailer.deliveries array.

It is recommended to clear it on test setup first:

<pre> <code class="ruby"> require File.join(File.dirname(FILE),’..’,’spec_helper’)

describe_mail UserMailer, :hello do

  before :each do
    Merb::Mailer.deliveries.clear
        end

end </code> </pre>

To do actual matching you can create a helper like this:

<pre> <code class="ruby"> def last_delivered_email

  Merb::Mailer.deliveries.last

end </code> </pre>

and use it like this:

<pre> <code class="ruby"> last_delivered_email.from.first.should == "no-reply@webapp.com" </code> </pre>

Note that MailFactory that is used by merb-mailer under the covers returns headers as Arrays. This is why we used from.first in example above.

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