This was the eight speech of a three day Rails training I gave in Tulsa, OK in the spring 2010.

1. Sending Email
With Callbacks
A look at ActionMailer and
the ActiveRecord life cycle

2. ActionMailer
The email library that comes with Rails

3. Mailers

4. Mailers
Mailers can be used to send email from Rails

5. Mailers
Mailers can be used to send email from Rails
Supports plain text, HTML, and multi-part emails

6. Mailers
Mailers can be used to send email from Rails
Supports plain text, HTML, and multi-part emails
Supports attachments

7. Mailers
Mailers can be used to send email from Rails
Supports plain text, HTML, and multi-part emails
Supports attachments
Multiple send modes including: sendmail and SMTP

8. Mailers
Mailers can be used to send email from Rails
Supports plain text, HTML, and multi-part emails
Supports attachments
Multiple send modes including: sendmail and SMTP
Mailers can also be used to receive emails

9. Mailers
Mailers can be used to send email from Rails
Supports plain text, HTML, and multi-part emails
Supports attachments
Multiple send modes including: sendmail and SMTP
Mailers can also be used to receive emails
Parses the email data into a Ruby object

10. M and V, Without the C

11. M and V, Without the C
Mailer structure is a bit different than other parts of Rails

12. M and V, Without the C
Mailer structure is a bit different than other parts of Rails
It’s a model

13. M and V, Without the C
Mailer structure is a bit different than other parts of Rails
It’s a model
But it has views

14. M and V, Without the C
Mailer structure is a bit different than other parts of Rails
It’s a model
But it has views
You can think of it as rendering content for the user, just
not through a browser

15. Email Example

16. Email Example
Let’s say I have an application built that requires users
to login to see any content

17. Email Example
Let’s say I have an application built that requires users
to login to see any content
I have created a User model and built the controller
that allows them to sign-up

18. Email Example
Let’s say I have an application built that requires users
to login to see any content
I have created a User model and built the controller
that allows them to sign-up
I have also wired up a login system using Authlogic

19. Email Example
Let’s say I have an application built that requires users
to login to see any content
I have created a User model and built the controller
that allows them to sign-up
I have also wired up a login system using Authlogic
The whole thing works now

20. A Problem

21. A Problem
I really need to make sure users give me a valid email

22. A Problem
I really need to make sure users give me a valid email
Authlogic checks the email address format, but you
can only know an email is valid by sending a message

23. Adding Authentication

24. Adding Authentication
When a user signs up:

25. Adding Authentication
When a user signs up:
We will send them an email with a special link in it

26. Adding Authentication
When a user signs up:
We will send them an email with a special link in it
Clicking that link will authenticate their address

27. Adding Authentication
When a user signs up:
We will send them an email with a special link in it
Clicking that link will authenticate their address
We won’t allow non-authenticated users access to the
site

28. Adding Authentication
When a user signs up:
We will send them an email with a special link in it
Clicking that link will authenticate their address
We won’t allow non-authenticated users access to the
site
After authentication, their account will work normally

29. Generate a Mailer

30. Generate a Mailer
We call script/
generate as usual
$ ruby script/generate mailer user_notifier activation
exists app/models/
create app/views/user_notifier
exists test/unit/
create test/fixtures/user_notifier
create app/models/user_notifier.rb
create test/unit/user_notifier_test.rb
create app/views/user_notifier/activation.erb
create test/fixtures/user_notifier/activation

31. Generate a Mailer
We call script/
generate as usual
We ask for a mailer $ ruby script/generate mailer user_notifier activation
exists app/models/
and name it create app/views/user_notifier
exists test/unit/
create test/fixtures/user_notifier
user_notifier create app/models/user_notifier.rb
create test/unit/user_notifier_test.rb
create app/views/user_notifier/activation.erb
create test/fixtures/user_notifier/activation

32. Generate a Mailer
We call script/
generate as usual
We ask for a mailer $ ruby script/generate mailer user_notifier activation
exists app/models/
and name it create app/views/user_notifier
exists test/unit/
create test/fixtures/user_notifier
user_notifier create app/models/user_notifier.rb
create test/unit/user_notifier_test.rb
create app/views/user_notifier/activation.erb
create test/fixtures/user_notifier/activation
Optionally, we can also
pass the names of
emails to create

33. app/models/user_notifier.rb
The generated mailer gets us started

34. class UserNotifier < ActionMailer::Base
def activation(sent_at = Time.now)
subject 'UserNotifier#activation'
recipients ''
from ''
sent_on sent_at
body :greeting => 'Hi,'
end
end
app/models/user_notifier.rb
The generated mailer gets us started

35. class UserNotifier < ActionMailer::Base
def activation(sent_at = Time.now)
subject 'UserNotifier#activation'
recipients ''
from ''
sent_on sent_at
body :greeting => 'Hi,'
end
end
app/models/user_notifier.rb
The generated mailer gets us started

36. class UserNotifier < ActionMailer::Base
def activation(sent_at = Time.now)
subject 'UserNotifier#activation'
recipients ''
from ''
sent_on sent_at
body :greeting => 'Hi,'
end
end
app/models/user_notifier.rb
The generated mailer gets us started

37. class UserNotifier < ActionMailer::Base
def activation(sent_at = Time.now)
subject 'UserNotifier#activation'
recipients ''
from ''
sent_on sent_at
body :greeting => 'Hi,'
end
end
app/models/user_notifier.rb
The generated mailer gets us started

38. class UserNotifier < ActionMailer::Base
def activation(sent_at = Time.now)
subject 'UserNotifier#activation'
recipients ''
from ''
sent_on sent_at
body :greeting => 'Hi,'
end
end
app/models/user_notifier.rb
The generated mailer gets us started

39. Customized to our Needs
We will work with a User since that makes sense
for what we are trying to do

40. class UserNotifier < ActionMailer::Base
def activation(user)
subject 'Activate Your Account'
recipients user.email
from 'admin@secureapp.com'
sent_on Time.now
body :user => user
end
end
Customized to our Needs
We will work with a User since that makes sense
for what we are trying to do

41. class UserNotifier < ActionMailer::Base
def activation(user)
subject 'Activate Your Account'
recipients user.email
from 'admin@secureapp.com'
sent_on Time.now
body :user => user
end
end
Customized to our Needs
We will work with a User since that makes sense
for what we are trying to do

42. class UserNotifier < ActionMailer::Base
def activation(user)
subject 'Activate Your Account'
recipients user.email
from 'admin@secureapp.com'
sent_on Time.now
body :user => user
end
end
Customized to our Needs
We will work with a User since that makes sense
for what we are trying to do

43. class UserNotifier < ActionMailer::Base
def activation(user)
subject 'Activate Your Account'
recipients user.email
from 'admin@secureapp.com'
sent_on Time.now
body :user => user
end
end
Customized to our Needs
We will work with a User since that makes sense
for what we are trying to do

44. The Email Content
This is the code from
app/views/user_notifier/activation.erb

45. Welcome to the Secure Application.
Please click the following link to activate your account:
<%= activate_url(:token => @user.perishable_token, :host => "localhost:3000") %>
The Email Content
This is the code from
app/views/user_notifier/activation.erb

46. Welcome to the Secure Application.
Please click the following link to activate your account:
<%= activate_url(:token => @user.perishable_token, :host => "localhost:3000") %>
The Email Content
This is the code from
app/views/user_notifier/activation.erb

47. Welcome to the Secure Application.
Please click the following link to activate your account:
<%= activate_url(:token => @user.perishable_token, :host => "localhost:3000") %>
The Email Content
This is the code from
app/views/user_notifier/activation.erb

48. Welcome to the Secure Application.
Please click the following link to activate your account:
<%= activate_url(:token => @user.perishable_token, :host => "localhost:3000") %>
The Email Content
This is the code from
app/views/user_notifier/activation.erb

49. Sending an Email

50. Sending an Email
You can send an email
from anywhere in the
application

51. Sending an Email
You can send an email
from anywhere in the
application
UserNotifier.deliver_activation(user)
Just call
deliver_EMAIL()
where EMAIL is the
name of the message

52. Mailers in Production

53. Mailers in Production
By default, ActionMailer will try to use sendmail to
deliver emails in production

54. Mailers in Production
By default, ActionMailer will try to use sendmail to
deliver emails in production
This works on a lot of servers but is not robust

55. Mailers in Production
By default, ActionMailer will try to use sendmail to
deliver emails in production
This works on a lot of servers but is not robust
I recommend setting up a Gmail account and
configuring ActionMailer to send via SMTP

56. Mailers in Production
By default, ActionMailer will try to use sendmail to
deliver emails in production
This works on a lot of servers but is not robust
I recommend setting up a Gmail account and
configuring ActionMailer to send via SMTP
You may also wish to shut off ActionMailer’s default
error raising behavior

57. Callbacks
Taking actions during the ActiveRecord life cycle

58. The ActiveRecord Life Cycle

59. The ActiveRecord Life Cycle
Models have a life cycle

60. The ActiveRecord Life Cycle
Models have a life cycle
They are created

61. The ActiveRecord Life Cycle
Models have a life cycle
They are created
Read from the database

62. The ActiveRecord Life Cycle
Models have a life cycle
They are created
Read from the database
Updated

63. The ActiveRecord Life Cycle
Models have a life cycle
They are created
Read from the database
Updated
Destroyed

64. The ActiveRecord Life Cycle
Models have a life cycle
They are created
Read from the database
Updated
Destroyed
Callbacks allow us to run code at points in this cycle

65. The Callback Hooks

66. The Callback Hooks
after_initialize*

67. The Callback Hooks
after_initialize*
before_save

68. The Callback Hooks
after_initialize*
before_save
before_create/update

69. The Callback Hooks
after_initialize*
before_save
before_create/update
before_validation

70. The Callback Hooks
after_initialize*
before_save
before_create/update
before_validation
before_validation_on_
create/update

71. The Callback Hooks
after_initialize*
before_save
before_create/update
before_validation
before_validation_on_
create/update
after_validation

72. The Callback Hooks
after_initialize* after_validation_on_cr
eate/update
before_save
before_create/update
before_validation
before_validation_on_
create/update
after_validation

73. The Callback Hooks
after_initialize* after_validation_on_cr
eate/update
before_save
after_save
before_create/update
before_validation
before_validation_on_
create/update
after_validation

74. The Callback Hooks
after_initialize* after_validation_on_cr
eate/update
before_save
after_save
before_create/update
after_create/update
before_validation
before_validation_on_
create/update
after_validation

75. The Callback Hooks
after_initialize* after_validation_on_cr
eate/update
before_save
after_save
before_create/update
after_create/update
before_validation
after_find*
before_validation_on_
create/update
after_validation

76. The Callback Hooks
after_initialize* after_validation_on_cr
eate/update
before_save
after_save
before_create/update
after_create/update
before_validation
after_find*
before_validation_on_
create/update before_destroy
after_validation

77. The Callback Hooks
after_initialize* after_validation_on_cr
eate/update
before_save
after_save
before_create/update
after_create/update
before_validation
after_find*
before_validation_on_
create/update before_destroy
after_validation after_destroy

78. Building a Callback
Just choose the type of callback, name a
method, and write a matching Ruby method

79. class User < ActiveRecord::Base
acts_as_authentic
after_create :send_activation_email
def send_activation_email
reset_perishable_token!
UserNotifier.deliver_activation(self)
end
end
Building a Callback
Just choose the type of callback, name a
method, and write a matching Ruby method

80. class User < ActiveRecord::Base
acts_as_authentic
after_create :send_activation_email
def send_activation_email
reset_perishable_token!
UserNotifier.deliver_activation(self)
end
end
Building a Callback
Just choose the type of callback, name a
method, and write a matching Ruby method

81. class User < ActiveRecord::Base
acts_as_authentic
after_create :send_activation_email
def send_activation_email
reset_perishable_token!
UserNotifier.deliver_activation(self)
end
end
Building a Callback
Just choose the type of callback, name a
method, and write a matching Ruby method

82. class User < ActiveRecord::Base
acts_as_authentic
after_create :send_activation_email
def send_activation_email
reset_perishable_token!
UserNotifier.deliver_activation(self)
end
end
Building a Callback
Just choose the type of callback, name a
method, and write a matching Ruby method

83. Not Just for Email

84. Not Just for Email
Sending email using callbacks is a common usage

85. Not Just for Email
Sending email using callbacks is a common usage
However, callbacks are a general tool with many uses

86. Not Just for Email
Sending email using callbacks is a common usage
However, callbacks are a general tool with many uses
For example:

87. Not Just for Email
Sending email using callbacks is a common usage
However, callbacks are a general tool with many uses
For example:
You might update an average_review_rating column
with an after_save on Review

88. Not Just for Email
Sending email using callbacks is a common usage
However, callbacks are a general tool with many uses
For example:
You might update an average_review_rating column
with an after_save on Review
You might generate a login column from a provided
email address in a before_validation on User

89. Completing the Example
We need to make some minor changes and
add a controller to get activation working

90. Migrating in Activation Fields
Rails migrations are pretty smart and can guess
where you want to add the fields

91. $ ruby script/generate migration add_activation_fields_to_users
perishable_token:string
active:boolean
Migrating in Activation Fields
Rails migrations are pretty smart and can guess
where you want to add the fields

92. $ ruby script/generate migration add_activation_fields_to_users
perishable_token:string
active:boolean
Migrating in Activation Fields
Rails migrations are pretty smart and can guess
where you want to add the fields

93. $ ruby script/generate migration add_activation_fields_to_users
perishable_token:string
active:boolean
Migrating in Activation Fields
Rails migrations are pretty smart and can guess
where you want to add the fields

94. $ ruby script/generate migration add_activation_fields_to_users
perishable_token:string
active:boolean
class AddActivationFieldsToUsers < ActiveRecord::Migration
def self.up
add_column :users, :perishable_token, :string
add_column :users, :active, :boolean, :default => false, :null => false
end
def self.down
remove_column :users, :active
remove_column :users, :perishable_token
end
end
Migrating in Activation Fields
Rails migrations are pretty smart and can guess
where you want to add the fields

95. $ ruby script/generate migration add_activation_fields_to_users
perishable_token:string
active:boolean
class AddActivationFieldsToUsers < ActiveRecord::Migration
def self.up
add_column :users, :perishable_token, :string
add_column :users, :active, :boolean, :default => false, :null => false
end
def self.down
remove_column :users, :active
remove_column :users, :perishable_token
end
end
Migrating in Activation Fields
Rails migrations are pretty smart and can guess
where you want to add the fields

96. $ ruby script/generate migration add_activation_fields_to_users
perishable_token:string
active:boolean
class AddActivationFieldsToUsers < ActiveRecord::Migration
def self.up
add_column :users, :perishable_token, :string
add_column :users, :active, :boolean, :default => false, :null => false
end
def self.down
remove_column :users, :active
remove_column :users, :perishable_token
end
end
$ rake db:migrate
Migrating in Activation Fields
Rails migrations are pretty smart and can guess
where you want to add the fields

97. Adding Activations
We look the user up by token, activate them,
and log them in

98. $ ruby script/generate controller activations
Adding Activations
We look the user up by token, activate them,
and log them in

99. $ ruby script/generate controller activations
class ActivationsController < ApplicationController
def create
if @user = User.find_using_perishable_token(params[:token])
@user.active = true # activate the user
@user.save
UserSession.create(@user) # log them in
flash[:notice] = "User activated."
else
flash[:error] = "User not found."
end
redirect_to root_path
end
end
Adding Activations
We look the user up by token, activate them,
and log them in

100. $ ruby script/generate controller activations
class ActivationsController < ApplicationController
def create
if @user = User.find_using_perishable_token(params[:token])
@user.active = true # activate the user
@user.save
UserSession.create(@user) # log them in
flash[:notice] = "User activated."
else
flash[:error] = "User not found."
end
redirect_to root_path
end
end
Adding Activations
We look the user up by token, activate them,
and log them in

101. $ ruby script/generate controller activations
class ActivationsController < ApplicationController
def create
if @user = User.find_using_perishable_token(params[:token])
@user.active = true # activate the user
@user.save
UserSession.create(@user) # log them in
flash[:notice] = "User activated."
else
flash[:error] = "User not found."
end
redirect_to root_path
end
end
Adding Activations
We look the user up by token, activate them,
and log them in

102. $ ruby script/generate controller activations
class ActivationsController < ApplicationController
def create
if @user = User.find_using_perishable_token(params[:token])
@user.active = true # activate the user
@user.save
UserSession.create(@user) # log them in
flash[:notice] = "User activated."
else
flash[:error] = "User not found."
end
redirect_to root_path
end
end
Adding Activations
We look the user up by token, activate them,
and log them in

103. Email Routing
We can’t make an email link POST,
so I created a custom route for the action

104. ActionController::Routing::Routes.draw do |map|
map.resources :users
map.resource :user_session
map.login "login", :controller => "user_sessions", :action => "new"
map.logout "logout", :controller => "user_sessions", :action => "destroy"
map.activate "activate/:token", :controller => "activations",
:action => "create"
map.root :controller => "home"
map.connect ':controller/:action/:id'
map.connect ':controller/:action/:id.:format'
end
Email Routing
We can’t make an email link POST,
so I created a custom route for the action

105. ActionController::Routing::Routes.draw do |map|
map.resources :users
map.resource :user_session
map.login "login", :controller => "user_sessions", :action => "new"
map.logout "logout", :controller => "user_sessions", :action => "destroy"
map.activate "activate/:token", :controller => "activations",
:action => "create"
map.root :controller => "home"
map.connect ':controller/:action/:id'
map.connect ':controller/:action/:id.:format'
end
Email Routing
We can’t make an email link POST,
so I created a custom route for the action

106. The Old Sign-up
Our old controller logs them in as they are
created and we can’t have that

107. class UsersController < ApplicationController
def new
@user = User.new
end
def create
@user = User.new(params[:user])
if @user.save
flash[:notice] = "Welcome!"
redirect_to root_path
else
flash.now[:error] = "Sign-up could not be completed."
render :action => :new
end
end
end
The Old Sign-up
Our old controller logs them in as they are
created and we can’t have that

108. class UsersController < ApplicationController
def new
@user = User.new
end
def create
@user = User.new(params[:user])
if @user.save
flash[:notice] = "Welcome!"
redirect_to root_path
else
flash.now[:error] = "Sign-up could not be completed."
render :action => :new
end
end
end
The Old Sign-up
Our old controller logs them in as they are
created and we can’t have that

109. class UsersController < ApplicationController
def new
@user = User.new
end
def create
@user = User.new(params[:user])
if @user.save
flash[:notice] = "Welcome!"
redirect_to root_path
else
flash.now[:error] = "Sign-up could not be completed."
render :action => :new
end
end
end
The Old Sign-up
Our old controller logs them in as they are
created and we can’t have that

110. Creation Without Login
Now we don’t log them in and we tell them to
check their email

111. class UsersController < ApplicationController
def new
@user = User.new
end
def create
@user = User.new(params[:user])
if @user.save_without_session_maintenance
flash[:notice] = "Please check your email to activate your account."
redirect_to login_path
else
flash.now[:error] = "Sign-up could not be completed."
render :action => :new
end
end
end
Creation Without Login
Now we don’t log them in and we tell them to
check their email

112. class UsersController < ApplicationController
def new
@user = User.new
end
def create
@user = User.new(params[:user])
if @user.save_without_session_maintenance
flash[:notice] = "Please check your email to activate your account."
redirect_to login_path
else
flash.now[:error] = "Sign-up could not be completed."
render :action => :new
end
end
end
Creation Without Login
Now we don’t log them in and we tell them to
check their email

113. class UsersController < ApplicationController
def new
@user = User.new
end
def create
@user = User.new(params[:user])
if @user.save_without_session_maintenance
flash[:notice] = "Please check your email to activate your account."
redirect_to login_path
else
flash.now[:error] = "Sign-up could not be completed."
render :action => :new
end
end
end
Creation Without Login
Now we don’t log them in and we tell them to
check their email

114. Activations in Action
Let’s see what we have created

115. Signing Up
I can create a new user with
my email address and desired password

116. Signing Up
I can create a new user with
my email address and desired password

117. Time to Check Email
I wasn’t logged in, as planned

118. Time to Check Email
I wasn’t logged in, as planned

119. Can’t Login Yet
I can’t login yet either,
since my account isn’t active yet

120. Can’t Login Yet
I can’t login yet either,
since my account isn’t active yet

121. log/development.rb
In development mode, emails are printed to
the log file (clear logs with: rake log:clear)

122. Sent mail to james@graysoftinc.com
Date: Sun, 7 Mar 2010 15:10:11 -0600
From: admin@secureapp.com
To: james@graysoftinc.com
Subject: Activate Your Account
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8
Welcome to the Secure Application.
Please click the following link to activate your account:
http://localhost:3000/activate/5HkeFFwiInKfjA4x25q9
log/development.rb
In development mode, emails are printed to
the log file (clear logs with: rake log:clear)

123. Activated and Logged In
Visiting the URL completes the process

124. Activated and Logged In
Visiting the URL completes the process

125. Questions?

126. User Emails Lab
Your book has instructions for how to add
email notifications to your application