Permalink
Browse files

Add the ability to intercept emails before previewing

To support the ability for tools like CSS style inliners to operate on emails
being previewed this commit adds a hook in a similar fashion to the existing
delivery interceptor hook, e.g:

  class CSSInlineStyler
    def self.previewing_email(message)
      # inline CSS styles
    end
  end

  ActionMailer::Base.register_preview_interceptor CSSInlineStyler

Fixes #13622.
  • Loading branch information...
1 parent 14d59d2 commit 35fd81672e02497c31f0b3cab965f4a38090229a @pixeltrix pixeltrix committed Jan 26, 2014
View
15 actionmailer/CHANGELOG.md
@@ -1,3 +1,18 @@
+* Add the ability to intercept emails before previewing in a similar fashion
+ to how emails can be intercepted before delivery, e.g:
+
+ class CSSInlineStyler
+ def self.previewing_email(message)
+ # inline CSS styles
+ end
+ end
+
+ ActionMailer::Base.register_preview_interceptor CSSInlineStyler
+
+ Fixes #13622.
+
+ *Andrew White*
+
* Add mailer previews feature based on 37 Signals mail_view gem
*Andrew White*
View
15 actionmailer/lib/action_mailer/base.rb
@@ -330,6 +330,21 @@ module ActionMailer
# An overview of all previews is accessible at <tt>http://localhost:3000/rails/mailers</tt>
# on a running development server instance.
#
+ # Previews can also be intercepted in a similar manner as deliveries can be by registering
+ # a preview interceptor that has a <tt>previewing_email</tt> method:
+ #
+ # class CssInlineStyler
+ # def self.previewing_email(message)
+ # # inline CSS styles
+ # end
+ # end
+ #
+ # config.action_mailer.register_preview_interceptor :css_inline_styler
+ #
+ # Note that interceptors need to be registered both with <tt>register_interceptor</tt>
+ # and <tt>register_preview_interceptor</tt> if they should operate on both sending and
+ # previewing emails.
+ #
# = Configuration options
#
# These options are specified on the class level, like
View
39 actionmailer/lib/action_mailer/preview.rb
@@ -10,6 +10,31 @@ module Previews #:nodoc:
# config.action_mailer.preview_path = "#{Rails.root}/lib/mailer_previews"
#
class_attribute :preview_path, instance_writer: false
+
+ # :nodoc:
+ mattr_accessor :preview_interceptors, instance_writer: false
+ self.preview_interceptors = []
+
+ # Register one or more Interceptors which will be called before mail is previewed.
+ def register_preview_interceptors(*interceptors)
+ interceptors.flatten.compact.each { |interceptor| register_preview_interceptor(interceptor) }
+ end
+
+ # Register am Interceptor which will be called before mail is previewed.
+ # Either a class or a string can be passed in as the Interceptor. If a
+ # string is passed in it will be <tt>constantize</tt>d.
+ def register_preview_interceptor(interceptor)
+ preview_interceptor = case interceptor
+ when String, Symbol
+ interceptor.to_s.camelize.constantize
+ else
+ interceptor
+ end
+
+ unless preview_interceptors.include?(preview_interceptor)
+ preview_interceptors << preview_interceptor
+ end
+ end
end
end
@@ -23,10 +48,14 @@ def all
descendants
end
- # Returns the mail object for the given email name
+ # Returns the mail object for the given email name. The registered preview
+ # interceptors will be informed so that they can transform the message
+ # as they would if the mail was actually being delivered.
def call(email)
preview = self.new
- preview.public_send(email)
+ message = preview.public_send(email)
+ inform_preview_interceptors(message)
+ message
end
# Returns all of the available email previews
@@ -68,6 +97,12 @@ def preview_path #:nodoc:
def preview_path? #:nodoc:
Base.preview_path?
end
+
+ def inform_preview_interceptors(message) #:nodoc:
+ Base.preview_interceptors.each do |interceptor|
+ interceptor.previewing_email(message)
+ end
+ end
end
end
end
View
45 actionmailer/test/base_test.rb
@@ -539,12 +539,18 @@ def self.delivered_email(mail)
end
class MyInterceptor
- def self.delivering_email(mail)
- end
+ def self.delivering_email(mail); end
+ def self.previewing_email(mail); end
end
class MySecondInterceptor
- def self.delivering_email(mail)
+ def self.delivering_email(mail); end
+ def self.previewing_email(mail); end
+ end
+
+ class BaseMailerPreview < ActionMailer::Preview
+ def welcome
+ BaseMailer.welcome
end
end
@@ -570,6 +576,39 @@ def self.delivering_email(mail)
mail.deliver
end
+ test "you can register a preview interceptor to the mail object that gets passed the mail object before previewing" do
+ ActionMailer::Base.register_preview_interceptor(MyInterceptor)
+ mail = BaseMailer.welcome
+ BaseMailerPreview.stubs(:welcome).returns(mail)
+ MyInterceptor.expects(:previewing_email).with(mail)
+ BaseMailerPreview.call(:welcome)
+ end
+
+ test "you can register a preview interceptor using its stringified name to the mail object that gets passed the mail object before previewing" do
+ ActionMailer::Base.register_preview_interceptor("BaseTest::MyInterceptor")
+ mail = BaseMailer.welcome
+ BaseMailerPreview.stubs(:welcome).returns(mail)
+ MyInterceptor.expects(:previewing_email).with(mail)
+ BaseMailerPreview.call(:welcome)
+ end
+
+ test "you can register an interceptor using its symbolized underscored name to the mail object that gets passed the mail object before previewing" do
+ ActionMailer::Base.register_preview_interceptor(:"base_test/my_interceptor")
+ mail = BaseMailer.welcome
+ BaseMailerPreview.stubs(:welcome).returns(mail)
+ MyInterceptor.expects(:previewing_email).with(mail)
+ BaseMailerPreview.call(:welcome)
+ end
+
+ test "you can register multiple preview interceptors to the mail object that both get passed the mail object before previewing" do
+ ActionMailer::Base.register_preview_interceptors("BaseTest::MyInterceptor", MySecondInterceptor)
+ mail = BaseMailer.welcome
+ BaseMailerPreview.stubs(:welcome).returns(mail)
+ MyInterceptor.expects(:previewing_email).with(mail)
+ MySecondInterceptor.expects(:previewing_email).with(mail)
+ BaseMailerPreview.call(:welcome)
+ end
+
test "being able to put proc's into the defaults hash and they get evaluated on mail sending" do
mail1 = ProcMailer.welcome['X-Proc-Method']
yesterday = 1.day.ago

0 comments on commit 35fd816

Please sign in to comment.