Merge branch 'master' into activestorage-guide

3 files changed, 31 insertions, 12 deletions

diff --git a/activestorage/lib/active_storage/attached/macros.rb b/activestorage/lib/active_storage/attached/macros.rb
index f0256718ac..2b38a9b887 100644
--- a/activestorage/lib/active_storage/attached/macros.rb
+++ b/activestorage/lib/active_storage/attached/macros.rb
@@ -32,6 +32,10 @@ module ActiveStorage
         def #{name}
           @active_storage_attached_#{name} ||= ActiveStorage::Attached::One.new("#{name}", self, dependent: #{dependent == :purge_later ? ":purge_later" : "false"})
         end
+
+        def #{name}=(attachable)
+          #{name}.attach(attachable)
+        end
       CODE
 
       has_one :"#{name}_attachment", -> { where(name: name) }, class_name: "ActiveStorage::Attachment", as: :record
@@ -73,6 +77,10 @@ module ActiveStorage
         def #{name}
           @active_storage_attached_#{name} ||= ActiveStorage::Attached::Many.new("#{name}", self, dependent: #{dependent == :purge_later ? ":purge_later" : "false"})
         end
+
+        def #{name}=(attachables)
+          #{name}.attach(attachables)
+        end
       CODE
 
       has_many :"#{name}_attachments", -> { where(name: name) }, as: :record, class_name: "ActiveStorage::Attachment"
diff --git a/activestorage/lib/active_storage/attached/many.rb b/activestorage/lib/active_storage/attached/many.rb
index 1e0657c33c..6eace65b79 100644
--- a/activestorage/lib/active_storage/attached/many.rb
+++ b/activestorage/lib/active_storage/attached/many.rb
@@ -13,7 +13,6 @@ module ActiveStorage
     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
@@ -21,7 +20,11 @@ module ActiveStorage
     #   document.images.attach([ first_blob, second_blob ])
     def attach(*attachables)
       attachables.flatten.collect do |attachable|
-        attachments.create!(name: name, blob: create_blob_from(attachable))
+        if record.new_record?
+          attachments.build(record: record, blob: create_blob_from(attachable))
+        else
+          attachments.create!(record: record, blob: create_blob_from(attachable))
+        end
       end
     end
 
@@ -36,6 +39,11 @@ module ActiveStorage
       attachments.any?
     end
 
+    # Deletes associated attachments without purging them, leaving their respective blobs in place.
+    def detach
+      attachments.destroy_all if attached?
+    end
+
     # Directly purges each associated attachment (i.e. destroys the blobs and
     # attachments and deletes the files on the service).
     def purge
diff --git a/activestorage/lib/active_storage/attached/one.rb b/activestorage/lib/active_storage/attached/one.rb
index dc19512484..0244232b2c 100644
--- a/activestorage/lib/active_storage/attached/one.rb
+++ b/activestorage/lib/active_storage/attached/one.rb
@@ -14,7 +14,6 @@ module ActiveStorage
     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
@@ -24,7 +23,7 @@ module ActiveStorage
       if attached? && dependent == :purge_later
         replace attachable
       else
-        write_attachment create_attachment_from(attachable)
+        write_attachment build_attachment_from(attachable)
       end
     end
 
@@ -39,6 +38,14 @@ module ActiveStorage
       attachment.present?
     end
 
+    # Deletes the attachment without purging it, leaving its blob in place.
+    def detach
+      if attached?
+        attachment.destroy
+        write_attachment nil
+      end
+    end
+
     # Directly purges the attachment (i.e. destroys the blob and
     # attachment and deletes the file on the service).
     def purge
@@ -59,18 +66,14 @@ module ActiveStorage
       def replace(attachable)
         blob.tap do
           transaction do
-            destroy_attachment
-            write_attachment create_attachment_from(attachable)
+            detach
+            write_attachment build_attachment_from(attachable)
           end
         end.purge_later
       end
 
-      def destroy_attachment
-        attachment.destroy
-      end
-
-      def create_attachment_from(attachable)
-        ActiveStorage::Attachment.create!(record: record, name: name, blob: create_blob_from(attachable))
+      def build_attachment_from(attachable)
+        ActiveStorage::Attachment.new(record: record, name: name, blob: create_blob_from(attachable))
       end
 
       def write_attachment(attachment)