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Diffstat (limited to 'guides/source/action_mailer_basics.md')
| -rw-r--r-- | guides/source/action_mailer_basics.md | 125 |
1 files changed, 78 insertions, 47 deletions
diff --git a/guides/source/action_mailer_basics.md b/guides/source/action_mailer_basics.md index ba26c922be..86d06508b0 100644 --- a/guides/source/action_mailer_basics.md +++ b/guides/source/action_mailer_basics.md @@ -20,9 +20,18 @@ Introduction ------------ Action Mailer allows you to send emails from your application using mailer classes -and views. Mailers work very similarly to controllers. They inherit from -`ActionMailer::Base` and live in `app/mailers`, and they have associated views -that appear in `app/views`. +and views. + +#### Mailers are similar to controllers + +They inherit from `ActionMailer::Base` and live in `app/mailers`. Mailers also work +very similarly to controllers. Some examples of similarities are enumerated below. +Mailers have: + +* Actions, and also, associated views that appear in `app/views`. +* Instance variables that are accessible in views. +* The ability to utilise layouts and partials. +* The ability to access a params hash. Sending Emails -------------- @@ -60,8 +69,7 @@ end ``` As you can see, you can generate mailers just like you use other generators with -Rails. Mailers are conceptually similar to controllers, and so we get a mailer, -a directory for views, and a test. +Rails. If you didn't want to use a generator, you could create your own file inside of `app/mailers`, just make sure that it inherits from `ActionMailer::Base`: @@ -73,10 +81,9 @@ end #### Edit the Mailer -Mailers are very similar to Rails controllers. They also have methods called -"actions" and use views to structure the content. Where a controller generates -content like HTML to send back to the client, a Mailer creates a message to be -delivered via email. +Mailers have methods called "actions" and they use views to structure their content. +Where a controller generates content like HTML to send back to the client, a Mailer +creates a message to be delivered via email. `app/mailers/user_mailer.rb` contains an empty mailer: @@ -92,8 +99,8 @@ registered email address: class UserMailer < ApplicationMailer default from: 'notifications@example.com' - def welcome_email(user) - @user = user + def welcome_email + @user = params[:user] @url = 'http://example.com/login' mail(to: @user.email, subject: 'Welcome to My Awesome Site') end @@ -110,9 +117,6 @@ messages in this class. This can be overridden on a per-email basis. * `mail` - The actual email message, we are passing the `:to` and `:subject` headers in. -Just like controllers, any instance variables we define in the method become -available for use in the views. - #### Create a Mailer View Create a file called `welcome_email.html.erb` in `app/views/user_mailer/`. This @@ -176,7 +180,7 @@ $ bin/rails db:migrate Now that we have a user model to play with, we will just edit the `app/controllers/users_controller.rb` make it instruct the `UserMailer` to deliver an email to the newly created user by editing the create action and inserting a -call to `UserMailer.welcome_email` right after the user is successfully saved. +call to `UserMailer.with(user: @user).welcome_email` right after the user is successfully saved. Action Mailer is nicely integrated with Active Job so you can send emails outside of the request-response cycle, so the user doesn't have to wait on it: @@ -191,7 +195,7 @@ class UsersController < ApplicationController respond_to do |format| if @user.save # Tell the UserMailer to send a welcome email after save - UserMailer.welcome_email(@user).deliver_later + UserMailer.with(user: @user).welcome_email.deliver_later format.html { redirect_to(@user, notice: 'User was successfully created.') } format.json { render json: @user, status: :created, location: @user } @@ -220,16 +224,21 @@ If you want to send emails right away (from a cronjob for example) just call class SendWeeklySummary def run User.find_each do |user| - UserMailer.weekly_summary(user).deliver_now + UserMailer.with(user: user).weekly_summary.deliver_now end end end ``` +Any key value pair passed to `with` just becomes the `params` for the mailer +action. So `with(user: @user, account: @user.account)` makes `params[:user]` and +`params[:account]` available in the mailer action. Just like controllers have +params. + The method `welcome_email` returns an `ActionMailer::MessageDelivery` object which can then just be told `deliver_now` or `deliver_later` to send itself out. The `ActionMailer::MessageDelivery` object is just a wrapper around a `Mail::Message`. If -you want to inspect, alter or do anything else with the `Mail::Message` object you can +you want to inspect, alter, or do anything else with the `Mail::Message` object you can access it with the `message` method on the `ActionMailer::MessageDelivery` object. ### Auto encoding header values @@ -261,7 +270,7 @@ Action Mailer makes it very easy to add attachments. * Pass the file name and content and Action Mailer and the [Mail gem](https://github.com/mikel/mail) will automatically guess the - mime_type, set the encoding and create the attachment. + mime_type, set the encoding, and create the attachment. ```ruby attachments['filename.jpg'] = File.read('/path/to/filename.jpg') @@ -331,7 +340,7 @@ with the addresses separated by commas. ```ruby class AdminMailer < ApplicationMailer - default to: Proc.new { Admin.pluck(:email) }, + default to: -> { Admin.pluck(:email) }, from: 'notification@example.com' def new_registration(user) @@ -351,8 +360,8 @@ address when they receive the email. The trick to doing that is to format the email address in the format `"Full Name" <email>`. ```ruby -def welcome_email(user) - @user = user +def welcome_email + @user = params[:user] email_with_name = %("#{@user.name}" <#{@user.email}>) mail(to: email_with_name, subject: 'Welcome to My Awesome Site') end @@ -372,8 +381,8 @@ To change the default mailer view for your action you do something like: class UserMailer < ApplicationMailer default from: 'notifications@example.com' - def welcome_email(user) - @user = user + def welcome_email + @user = params[:user] @url = 'http://example.com/login' mail(to: @user.email, subject: 'Welcome to My Awesome Site', @@ -394,8 +403,8 @@ templates or even render inline or text without using a template file: class UserMailer < ApplicationMailer default from: 'notifications@example.com' - def welcome_email(user) - @user = user + def welcome_email + @user = params[:user] @url = 'http://example.com/login' mail(to: @user.email, subject: 'Welcome to My Awesome Site') do |format| @@ -413,7 +422,7 @@ inside of Action Controller, so you can use all the same options, such as #### Caching mailer view -You can do cache in mailer views like in application views using `cache` method. +You can perform fragment caching in mailer views like in application views using the `cache` method. ``` <% cache do %> @@ -427,6 +436,9 @@ And in order to use this feature, you need to configure your application with th config.action_mailer.perform_caching = true ``` +Fragment caching is also supported in multipart emails. +Read more about caching in the [Rails caching guide](caching_with_rails.html). + ### Action Mailer Layouts Just like controller views, you can also have mailer layouts. The layout name @@ -450,8 +462,8 @@ the format block to specify different layouts for different formats: ```ruby class UserMailer < ApplicationMailer - def welcome_email(user) - mail(to: user.email) do |format| + def welcome_email + mail(to: params[:user].email) do |format| format.html { render layout: 'my_layout' } format.text end @@ -474,7 +486,7 @@ special URL that renders them. In the above example, the preview class for ```ruby class UserMailerPreview < ActionMailer::Preview def welcome_email - UserMailer.welcome_email(User.first) + UserMailer.with(user: User.first).welcome_email end end ``` @@ -591,12 +603,12 @@ mailer action. ```ruby class UserMailer < ApplicationMailer - def welcome_email(user, company) - @user = user + def welcome_email + @user = params[:user] @url = user_url(@user) - delivery_options = { user_name: company.smtp_user, - password: company.smtp_password, - address: company.smtp_host } + delivery_options = { user_name: params[:company].smtp_user, + password: params[:company].smtp_password, + address: params[:company].smtp_host } mail(to: @user.email, subject: "Please see the Terms and Conditions attached", delivery_method_options: delivery_options) @@ -613,9 +625,9 @@ will default to `text/plain` otherwise. ```ruby class UserMailer < ApplicationMailer - def welcome_email(user, email_body) - mail(to: user.email, - body: email_body, + def welcome_email + mail(to: params[:user].email, + body: params[:email_body], content_type: "text/html", subject: "Already rendered!") end @@ -674,24 +686,43 @@ Action Mailer allows for you to specify a `before_action`, `after_action` and * You could use a `before_action` to populate the mail object with defaults, delivery_method_options or insert default headers and attachments. +```ruby +class InvitationsMailer < ApplicationMailer + before_action { @inviter, @invitee = params[:inviter], params[:invitee] } + before_action { @account = params[:inviter].account } + + default to: -> { @invitee.email_address }, + from: -> { common_address(@inviter) }, + reply_to: -> { @inviter.email_address_with_name } + + def account_invitation + mail subject: "#{@inviter.name} invited you to their Basecamp (#{@account.name})" + end + + def project_invitation + @project = params[:project] + @summarizer = ProjectInvitationSummarizer.new(@project.bucket) + + mail subject: "#{@inviter.name.familiar} added you to a project in Basecamp (#{@account.name})" + end +end +``` + * You could use an `after_action` to do similar setup as a `before_action` but using instance variables set in your mailer action. ```ruby class UserMailer < ApplicationMailer + before_action { @business, @user = params[:business], params[:user] } + after_action :set_delivery_options, :prevent_delivery_to_guests, :set_business_headers - def feedback_message(business, user) - @business = business - @user = user - mail + def feedback_message end - def campaign_message(business, user) - @business = business - @user = user + def campaign_message end private @@ -778,9 +809,9 @@ config.action_mailer.smtp_settings = { user_name: '<username>', password: '<password>', authentication: 'plain', - enable_starttls_auto: true } + enable_starttls_auto: true } ``` -Note: As of July 15, 2014, Google increased [its security measures](https://support.google.com/accounts/answer/6010255) and now blocks attempts from apps it deems less secure. +NOTE: As of July 15, 2014, Google increased [its security measures](https://support.google.com/accounts/answer/6010255) and now blocks attempts from apps it deems less secure. You can change your Gmail settings [here](https://www.google.com/settings/security/lesssecureapps) to allow the attempts. If your Gmail account has 2-factor authentication enabled, then you will need to set an [app password](https://myaccount.google.com/apppasswords) and use that instead of your regular password. Alternatively, you can use another ESP to send email by replacing 'smtp.gmail.com' above with the address of your provider. |