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Diffstat (limited to 'guides/source/action_mailer_basics.md')
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1 files changed, 109 insertions, 30 deletions
diff --git a/guides/source/action_mailer_basics.md b/guides/source/action_mailer_basics.md index cb1c1c653d..73b240ff2c 100644 --- a/guides/source/action_mailer_basics.md +++ b/guides/source/action_mailer_basics.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON http://guides.rubyonrails.org.** + Action Mailer Basics ==================== @@ -35,10 +37,26 @@ views. ```bash $ bin/rails generate mailer UserMailer create app/mailers/user_mailer.rb +create app/mailers/application_mailer.rb invoke erb create app/views/user_mailer +create app/views/layouts/mailer.text.erb +create app/views/layouts/mailer.html.erb invoke test_unit create test/mailers/user_mailer_test.rb +create test/mailers/previews/user_mailer_preview.rb +``` + +```ruby +# app/mailers/application_mailer.rb +class ApplicationMailer < ActionMailer::Base + default from: "from@example.com" + layout 'mailer' +end + +# app/mailers/user_mailer.rb +class UserMailer < ApplicationMailer +end ``` As you can see, you can generate mailers just like you use other generators with @@ -63,8 +81,7 @@ delivered via email. `app/mailers/user_mailer.rb` contains an empty mailer: ```ruby -class UserMailer < ActionMailer::Base - default from: 'from@example.com' +class UserMailer < ApplicationMailer end ``` @@ -72,7 +89,7 @@ Let's add a method called `welcome_email`, that will send an email to the user's registered email address: ```ruby -class UserMailer < ActionMailer::Base +class UserMailer < ApplicationMailer default from: 'notifications@example.com' def welcome_email(user) @@ -159,7 +176,10 @@ $ bin/rake 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.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: ```ruby class UsersController < ApplicationController @@ -171,7 +191,7 @@ 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 + UserMailer.welcome_email(@user).deliver_later format.html { redirect_to(@user, notice: 'User was successfully created.') } format.json { render json: @user, status: :created, location: @user } @@ -184,8 +204,29 @@ class UsersController < ApplicationController end ``` -The method `welcome_email` returns a `Mail::Message` object which can then just -be told `deliver` to send itself out. +NOTE: Active Job's default behavior is to execute jobs ':inline'. So, you can use +`deliver_later` now to send emails, and when you later decide to start sending +them from a background job, you'll only need to set up Active Job to use a queueing +backend (Sidekiq, Resque, etc). + +If you want to send emails right away (from a cronjob for example) just call +`deliver_now`: + +```ruby +class SendWeeklySummary + def run + User.find_each do |user| + UserMailer.weekly_summary(user).deliver_now + end + end +end +``` + +The method `welcome_email` returns a `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 +access it with the `message` method on the `ActionMailer::MessageDelivery` object. ### Auto encoding header values @@ -274,8 +315,7 @@ Action Mailer 3.0 makes inline attachments, which involved a lot of hacking in p ```html+erb <p>Hello there, this is our image</p> - <%= image_tag attachments['image.jpg'].url, alt: 'My Photo', - class: 'photos' %> + <%= image_tag attachments['image.jpg'].url, alt: 'My Photo', class: 'photos' %> ``` #### Sending Email To Multiple Recipients @@ -325,7 +365,7 @@ for the HTML version and `welcome_email.text.erb` for the plain text version. To change the default mailer view for your action you do something like: ```ruby -class UserMailer < ActionMailer::Base +class UserMailer < ApplicationMailer default from: 'notifications@example.com' def welcome_email(user) @@ -347,7 +387,7 @@ If you want more flexibility you can also pass a block and render specific templates or even render inline or text without using a template file: ```ruby -class UserMailer < ActionMailer::Base +class UserMailer < ApplicationMailer default from: 'notifications@example.com' def welcome_email(user) @@ -377,7 +417,7 @@ layout. In order to use a different file, call `layout` in your mailer: ```ruby -class UserMailer < ActionMailer::Base +class UserMailer < ApplicationMailer layout 'awesome' # use awesome.(html|text).erb as the layout end ``` @@ -389,7 +429,7 @@ You can also pass in a `layout: 'layout_name'` option to the render call inside the format block to specify different layouts for different formats: ```ruby -class UserMailer < ActionMailer::Base +class UserMailer < ApplicationMailer def welcome_email(user) mail(to: user.email) do |format| format.html { render layout: 'my_layout' } @@ -402,6 +442,39 @@ end Will render the HTML part using the `my_layout.html.erb` file and the text part with the usual `user_mailer.text.erb` file if it exists. +### Previewing Emails + +Action Mailer previews provide a way to see how emails look by visiting a +special URL that renders them. In the above example, the preview class for +`UserMailer` should be named `UserMailerPreview` and located in +`test/mailers/previews/user_mailer_preview.rb`. To see the preview of +`welcome_email`, implement a method that has the same name and call +`UserMailer.welcome_email`: + +```ruby +class UserMailerPreview < ActionMailer::Preview + def welcome_email + UserMailer.welcome_email(User.first) + end +end +``` + +Then the preview will be available in <http://localhost:3000/rails/mailers/user_mailer/welcome_email>. + +If you change something in `app/views/user_mailer/welcome_email.html.erb` +or the mailer itself, it'll automatically reload and render it so you can +visually see the new style instantly. A list of previews are also available +in <http://localhost:3000/rails/mailers>. + +By default, these preview classes live in `test/mailers/previews`. +This can be configured using the `preview_path` option. For example, if you +want to change it to `lib/mailer_previews`, you can configure it in +`config/application.rb`: + +```ruby +config.action_mailer.preview_path = "#{Rails.root}/lib/mailer_previews" +``` + ### Generating URLs in Action Mailer Views Unlike controllers, the mailer instance doesn't have any context about the @@ -414,18 +487,25 @@ globally in `config/application.rb`: config.action_mailer.default_url_options = { host: 'example.com' } ``` -#### generating URLs with `url_for` +Because of this behavior you cannot use any of the `*_path` helpers inside of +an email. Instead you will need to use the associated `*_url` helper. For example +instead of using + +``` +<%= link_to 'welcome', welcome_path %> +``` -You need to pass the `only_path: false` option when using `url_for`. This will -ensure that absolute URLs are generated because the `url_for` view helper will, -by default, generate relative URLs when a `:host` option isn't explicitly -provided. +You will need to use: -```erb -<%= url_for(controller: 'welcome', - action: 'greeting', - only_path: false) %> ``` +<%= link_to 'welcome', welcome_url %> +``` + +By using the full URL, your links will now work in your emails. + +#### generating URLs with `url_for` + +`url_for` generate full URL by default in templates. If you did not configure the `:host` option globally make sure to pass it to `url_for`. @@ -437,9 +517,6 @@ If you did not configure the `:host` option globally make sure to pass it to action: 'greeting') %> ``` -NOTE: When you explicitly pass the `:host` Rails will always generate absolute -URLs, so there is no need to pass `only_path: false`. - #### generating URLs with named routes Email clients have no web context and so paths have no base URL to form complete @@ -471,7 +548,7 @@ while delivering emails, you can do this using `delivery_method_options` in the mailer action. ```ruby -class UserMailer < ActionMailer::Base +class UserMailer < ApplicationMailer def welcome_email(user, company) @user = user @url = user_url(@user) @@ -493,7 +570,7 @@ option. In such cases don't forget to add the `:content_type` option. Rails will default to `text/plain` otherwise. ```ruby -class UserMailer < ActionMailer::Base +class UserMailer < ApplicationMailer def welcome_email(user, email_body) mail(to: user.email, body: email_body, @@ -523,7 +600,7 @@ mailer, and pass the email object to the mailer `receive` instance method. Here's an example: ```ruby -class UserMailer < ActionMailer::Base +class UserMailer < ApplicationMailer def receive(email) page = Page.find_by(address: email.to.first) page.emails.create( @@ -559,7 +636,7 @@ Action Mailer allows for you to specify a `before_action`, `after_action` and using instance variables set in your mailer action. ```ruby -class UserMailer < ActionMailer::Base +class UserMailer < ApplicationMailer after_action :set_delivery_options, :prevent_delivery_to_guests, :set_business_headers @@ -689,7 +766,9 @@ Mailer framework. You can do this in an initializer file `config/initializers/sandbox_email_interceptor.rb` ```ruby -ActionMailer::Base.register_interceptor(SandboxEmailInterceptor) if Rails.env.staging? +if Rails.env.staging? + ActionMailer::Base.register_interceptor(SandboxEmailInterceptor) +end ``` NOTE: The example above uses a custom environment called "staging" for a |