Add ActiveStorage::Blob#open

[David Robertson & George Claghorn]

2 files changed, 8 insertions, 5 deletions

diff --git a/activestorage/app/models/active_storage/blob.rb b/activestorage/app/models/active_storage/blob.rb
index b8b3b62f22..9bf0766843 100644
--- a/activestorage/app/models/active_storage/blob.rb
+++ b/activestorage/app/models/active_storage/blob.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require "active_storage/downloader"
+
 # A blob is a record that contains the metadata about a file and a key for where that file resides on the service.
 # Blobs can be created in two ways:
 #
@@ -164,6 +166,11 @@ class ActiveStorage::Blob < ActiveRecord::Base
     service.download key, &block
   end
 
+  # Downloads the blob to a tempfile on disk. Yields the tempfile.
+  def open(&block)
+    ActiveStorage::Downloader.new(self).download_blob_to_tempfile(&block)
+  end
+
 
   # Deletes the file on the service that's associated with this blob. This should only be done if the blob is going to be
   # deleted as well or you will essentially have a dead reference. It's recommended to use the +#purge+ and +#purge_later+
diff --git a/activestorage/app/models/active_storage/variant.rb b/activestorage/app/models/active_storage/variant.rb
index b782489a92..2a7006553c 100644
--- a/activestorage/app/models/active_storage/variant.rb
+++ b/activestorage/app/models/active_storage/variant.rb
@@ -1,7 +1,5 @@
 # frozen_string_literal: true
 
-require "active_storage/downloading"
-
 # Image blobs can have variants that are the result of a set of transformations applied to the original.
 # These variants are used to create thumbnails, fixed-size avatars, or any other derivative image from the
 # original.
@@ -53,8 +51,6 @@ require "active_storage/downloading"
 # * {ImageProcessing::Vips}[https://github.com/janko-m/image_processing/blob/master/doc/vips.md#methods]
 # * {ruby-vips reference}[http://www.rubydoc.info/gems/ruby-vips/Vips/Image]
 class ActiveStorage::Variant
-  include ActiveStorage::Downloading
-
   WEB_IMAGE_CONTENT_TYPES = %w( image/png image/jpeg image/jpg image/gif )
 
   attr_reader :blob, :variation
@@ -98,7 +94,7 @@ class ActiveStorage::Variant
     end
 
     def process
-      download_blob_to_tempfile do |image|
+      blob.open do |image|
         transform image do |output|
           upload output
         end