Add 'activestorage/' from commit '3f4a7218a4a4923a0e7ce1b2eb0d2888ce30da58'

git-subtree-dir: activestorage
git-subtree-mainline: 0d58e7e478e79c2d6b2a39a4444d2a17a903b2a6
git-subtree-split: 3f4a7218a4a4923a0e7ce1b2eb0d2888ce30da58

3 files changed, 183 insertions, 0 deletions

diff --git a/activestorage/lib/active_storage/attached/macros.rb b/activestorage/lib/active_storage/attached/macros.rb
new file mode 100644
index 0000000000..89297e5bdf
--- /dev/null
+++ b/activestorage/lib/active_storage/attached/macros.rb
@@ -0,0 +1,76 @@
+# Provides the class-level DSL for declaring that an Active Record model has attached blobs.
+module ActiveStorage::Attached::Macros
+  # Specifies the relation between a single attachment and the model.
+  #
+  #   class User < ActiveRecord::Base
+  #     has_one_attached :avatar
+  #   end
+  #
+  # There is no column defined on the model side, Active Storage takes
+  # care of the mapping between your records and the attachment.
+  #
+  # Under the covers, this relationship is implemented as a `has_one` association to a
+  # `ActiveStorage::Attachment` record and a `has_one-through` association to a
+  # `ActiveStorage::Blob` record. These associations are available as `avatar_attachment`
+  # and `avatar_blob`. But you shouldn't need to work with these associations directly in
+  # most circumstances.
+  #
+  # The system has been designed to having you go through the `ActiveStorage::Attached::One`
+  # proxy that provides the dynamic proxy to the associations and factory methods, like `#attach`.
+  #
+  # If the +:dependent+ option isn't set, the attachment will be purged
+  # (i.e. destroyed) whenever the record is destroyed.
+  def has_one_attached(name, dependent: :purge_later)
+    define_method(name) do
+      instance_variable_get("@active_storage_attached_#{name}") ||
+        instance_variable_set("@active_storage_attached_#{name}", ActiveStorage::Attached::One.new(name, self))
+    end
+
+    has_one :"#{name}_attachment", -> { where(name: name) }, class_name: "ActiveStorage::Attachment", as: :record
+    has_one :"#{name}_blob", through: :"#{name}_attachment", class_name: "ActiveStorage::Blob", source: :blob
+
+    if dependent == :purge_later
+      before_destroy { public_send(name).purge_later }
+    end
+  end
+
+  # Specifies the relation between multiple attachments and the model.
+  #
+  #   class Gallery < ActiveRecord::Base
+  #     has_many_attached :photos
+  #   end
+  #
+  # There are no columns defined on the model side, Active Storage takes
+  # care of the mapping between your records and the attachments.
+  #
+  # To avoid N+1 queries, you can include the attached blobs in your query like so:
+  #
+  #   Gallery.where(user: Current.user).with_attached_photos
+  #
+  # Under the covers, this relationship is implemented as a `has_many` association to a
+  # `ActiveStorage::Attachment` record and a `has_many-through` association to a
+  # `ActiveStorage::Blob` record. These associations are available as `photos_attachments`
+  # and `photos_blobs`. But you shouldn't need to work with these associations directly in
+  # most circumstances.
+  #
+  # The system has been designed to having you go through the `ActiveStorage::Attached::Many`
+  # proxy that provides the dynamic proxy to the associations and factory methods, like `#attach`.
+  #
+  # If the +:dependent+ option isn't set, all the attachments will be purged
+  # (i.e. destroyed) whenever the record is destroyed.
+  def has_many_attached(name, dependent: :purge_later)
+    define_method(name) do
+      instance_variable_get("@active_storage_attached_#{name}") ||
+        instance_variable_set("@active_storage_attached_#{name}", ActiveStorage::Attached::Many.new(name, self))
+    end
+
+    has_many :"#{name}_attachments", -> { where(name: name) }, as: :record, class_name: "ActiveStorage::Attachment"
+    has_many :"#{name}_blobs", through: :"#{name}_attachments", class_name: "ActiveStorage::Blob", source: :blob
+
+    scope :"with_attached_#{name}", -> { includes("#{name}_attachments": :blob) }
+
+    if dependent == :purge_later
+      before_destroy { public_send(name).purge_later }
+    end
+  end
+end
diff --git a/activestorage/lib/active_storage/attached/many.rb b/activestorage/lib/active_storage/attached/many.rb
new file mode 100644
index 0000000000..035cd9c091
--- /dev/null
+++ b/activestorage/lib/active_storage/attached/many.rb
@@ -0,0 +1,51 @@
+# Decorated proxy object representing of multiple attachments to a model.
+class ActiveStorage::Attached::Many < ActiveStorage::Attached
+  delegate_missing_to :attachments
+
+  # Returns all the associated attachment records.
+  #
+  # All methods called on this proxy object that aren't listed here will automatically be delegated to `attachments`.
+  def attachments
+    record.public_send("#{name}_attachments")
+  end
+
+  # Associates one or several attachments with the current record, saving them to the database.
+  # Examples:
+  #
+  #   document.images.attach(params[:images]) # Array of ActionDispatch::Http::UploadedFile objects
+  #   document.images.attach(params[:signed_blob_id]) # Signed reference to blob from direct upload
+  #   document.images.attach(io: File.open("~/racecar.jpg"), filename: "racecar.jpg", content_type: "image/jpg")
+  #   document.images.attach([ first_blob, second_blob ])
+  def attach(*attachables)
+    attachables.flatten.collect do |attachable|
+      attachments.create!(name: name, blob: create_blob_from(attachable))
+    end
+  end
+
+  # Returns true if any attachments has been made.
+  #
+  #   class Gallery < ActiveRecord::Base
+  #     has_many_attached :photos
+  #   end
+  #
+  #   Gallery.new.photos.attached? # => false
+  def attached?
+    attachments.any?
+  end
+
+  # Directly purges each associated attachment (i.e. destroys the blobs and
+  # attachments and deletes the files on the service).
+  def purge
+    if attached?
+      attachments.each(&:purge)
+      attachments.reload
+    end
+  end
+
+  # Purges each associated attachment through the queuing system.
+  def purge_later
+    if attached?
+      attachments.each(&:purge_later)
+    end
+  end
+end
diff --git a/activestorage/lib/active_storage/attached/one.rb b/activestorage/lib/active_storage/attached/one.rb
new file mode 100644
index 0000000000..0c522e856e
--- /dev/null
+++ b/activestorage/lib/active_storage/attached/one.rb
@@ -0,0 +1,56 @@
+# Representation of a single attachment to a model.
+class ActiveStorage::Attached::One < ActiveStorage::Attached
+  delegate_missing_to :attachment
+
+  # Returns the associated attachment record.
+  #
+  # You don't have to call this method to access the attachment's methods as
+  # they are all available at the model level.
+  def attachment
+    record.public_send("#{name}_attachment")
+  end
+
+  # Associates a given attachment with the current record, saving it to the database.
+  # Examples:
+  #
+  #   person.avatar.attach(params[:avatar]) # ActionDispatch::Http::UploadedFile object
+  #   person.avatar.attach(params[:signed_blob_id]) # Signed reference to blob from direct upload
+  #   person.avatar.attach(io: File.open("~/face.jpg"), filename: "face.jpg", content_type: "image/jpg")
+  #   person.avatar.attach(avatar_blob) # ActiveStorage::Blob object
+  def attach(attachable)
+    write_attachment \
+      ActiveStorage::Attachment.create!(record: record, name: name, blob: create_blob_from(attachable))
+  end
+
+  # Returns true if an attachment has been made.
+  #
+  #   class User < ActiveRecord::Base
+  #     has_one_attached :avatar
+  #   end
+  #
+  #   User.new.avatar.attached? # => false
+  def attached?
+    attachment.present?
+  end
+
+  # Directly purges the attachment (i.e. destroys the blob and
+  # attachment and deletes the file on the service).
+  def purge
+    if attached?
+      attachment.purge
+      write_attachment nil
+    end
+  end
+
+  # Purges the attachment through the queuing system.
+  def purge_later
+    if attached?
+      attachment.purge_later
+    end
+  end
+
+  private
+    def write_attachment(attachment)
+      record.public_send("#{name}_attachment=", attachment)
+    end
+end