Add metadata to draft

README.md

@@ -66,16 +66,45 @@ drafts = Message.drafts(current_user)
 messages = drafts.restore_all
 ```
 
-### Migration
+### Migrations & Their Features
+
+If you are upgrading from previous versions, simply run `rails g drafting:migration` again to generate the mising migration files.
 
 #### 0.5.x
 
 Starting from 0.5.x, you will be able to save drafts under a non `User` model as such:
-```
+
+```ruby
 message.save_draft(author)
 ```
 
-If you are upgrading from previous versions, simply run `rails g drafting:migration` again to generate the mising migration files.
+#### 0.6.x
+
+Starting from 0.6.x, you will be able to save metadata to your `draft` (eg. to label your drafts) as such:
+
+```ruby
+message.save_draft(author, { title: 'Final Draft 2022-08-06' })
+draft = Draft.find(message.draft_id)
+draft.title # => 'Final Draft 2022-08-06'
+
+message.update_draft(
+  author,
+  { content: 'New content for message' },
+  {
+    title: 'Final Final Draft 2022-08-06',
+    version: '1.123'
+  }
+)
+message.content # => 'New content for message'
+draft = Draft.find(message.draft_id)
+draft.title # => 'Final Final Draft 2022-08-06'
+draft.version # => '1.123'
+draft.version = '1.5'
+draft.save
+draft.reload.version # => '1.5'
+```
+
+Note that the `metadata` on the draft is essentially a [Rails store](https://api.rubyonrails.org/classes/ActiveRecord/Store.html) whose keys are dynamically generated according to your application needs. They are generated on the fly via `method_missing`.
 
 ### Linking to parent instance
 

bin/console

@@ -4,7 +4,9 @@ require "bundler/setup"
 require "drafting"
 
 $LOAD_PATH.unshift(File.expand_path('..', File.dirname(__FILE__)))
-require 'lib/generators/drafting/migration/templates/migration.rb'
+Dir["#{Drafting.root}/lib/generators/drafting/migration/templates/*.rb"].each do |filename|
+  require filename
+end
 require 'spec/support/spec_migration.rb'
 
 require 'spec/models/user'
@@ -24,7 +26,9 @@ ActiveRecord::Base.configurations = YAML.load_file('spec/database.yml')
 ActiveRecord::Base.establish_connection(:sqlite)
 ActiveRecord::Migration.verbose = false
 
-DraftingMigration.up
+Drafting::MigrationGenerator.loop_through_migration_files do |_, filename|
+  Object.const_get(filename.gsub('.rb', '').camelize).up
+end
 SpecMigration.up
 
 require "irb"

lib/drafting/draft.rb

@@ -4,11 +4,30 @@ class Draft < ActiveRecord::Base
 
   validates_presence_of :data, :target_type
 
+  store :metadata, accessors: [], coder: JSON
+
   def restore
     target_type.constantize.from_draft(self)
   end
 
   def self.restore_all
     find_each.map(&:restore)
   end
+
+  private
+
+  def method_missing(name, *args)
+    method_name = name.to_s
+    if method_name !~ /[a-z0-9_]+=?$/
+      super
+    else
+      # TODO: executing on instance's class, not on it's eigenclass, so that store_accessors are permanent in application lifecycle, good idea? 🤔
+      Draft.store_accessor :metadata, method_name.gsub('=', "").to_sym
+      public_send(name, *args)
+    end
+  end
+
+  def respond_to_missing?(sym, include_private)
+    true
+  end
 end

lib/drafting/instance_methods.rb

@@ -1,6 +1,6 @@
 module Drafting
   module InstanceMethods
-    def save_draft(user=nil)
+    def save_draft(user=nil, metadata={})
       return false unless self.new_record?
 
       draft = Draft.find_by_id(self.draft_id) || Draft.new
@@ -10,16 +10,20 @@ def save_draft(user=nil)
       draft.user_id = user.try(:id)
       draft.user_type = user.try(:class).try(:name)
       draft.parent = self.send(self.class.draft_parent) if self.class.draft_parent
+      metadata = metadata.with_indifferent_access
+      metadata.each_key do |key|
+        draft.public_send("#{key}=", metadata[key])
+      end
 
       result = draft.save
       self.draft_id = draft.id if result
       result
     end
 
-    def update_draft(user, attributes)
+    def update_draft(user, attributes, metadata={})
       with_transaction_returning_status do
         assign_attributes(attributes)
-        save_draft(user)
+        save_draft(user, metadata)
       end
     end
 

lib/drafting/version.rb

@@ -1,3 +1,7 @@
 module Drafting
-  VERSION = "0.5.1"
+  VERSION = "0.6.0"
+
+  def self.root
+    File.expand_path '../../..', __FILE__
+  end
 end

lib/generators/drafting/migration/migration_generator.rb

@@ -8,19 +8,54 @@ class MigrationGenerator < Rails::Generators::Base
     desc 'Generates migration for Drafting'
     source_root File.expand_path('../templates', __FILE__)
 
-    def create_migration_file
-      migration_template 'migration.rb', 'db/migrate/drafting_migration.rb'
-      migration_template 'non_user_migration.rb', 'db/migrate/non_user_drafting_migration.rb'
+    def self.loop_through_migration_files(reverse: false)
+      files = Dir.glob("#{MigrationGenerator.source_root}/*.rb")
+
+      files = files.reverse if reverse
+
+      files.each_with_index do |abs_path, index|
+        original_filename = File.basename(abs_path)
+        filename = original_filename.split('-').last
+
+        yield original_filename, filename, index
+      end
+    end
+
+    def validation
+      Drafting::MigrationGenerator.loop_through_migration_files do |original_filename|
+        # these numbers will keep the migration files generated in order
+        # for backwards compatibility, do NOT change the order of existing migration file templates🙏
+        raise 'Migration files should start with a number followed by a dash to dictate the order of migration files to be generated' if original_filename !~ /^[\d]+\-.*drafting_migration\.rb/
+      end
+    end
+
+    #########
+    # USAGE #
+    #########
+
+    # Instance methods in this Generator will run in sequence (starting from `validation` above👆)
+    # The methods generated dynamically below will create the migration file in order
+    # This order is dictated by the number prefix in the name of the migration template files
+    # naming format should follow: `<number>-custom_name_drafting_migration.rb`
+
+    loop_through_migration_files do |original_filename, filename, index|
+      define_method "create_migration_file#{index}" do
+        migration_template original_filename, "db/migrate/#{filename}"
+      end
     end
 
     def self.next_migration_number(dirname)
-      if ActiveRecord::Base.timestamped_migrations
-        # ensure timestamp of the multiple migration files generated
-        # will be different
-        timestamp = Time.now.utc.strftime("%Y%m%d%H%M%S").to_i
-        timestamp += 1 if current_migration_number(dirname) == timestamp
+      format = '%Y%m%d%H%M%S'
+
+      # check if migration number already a timestamp for timestamped migrations
+      # strptime throws error, and rescue handles if not the case
+      DateTime.strptime(current_migration_number(dirname).to_s, format)
 
-        timestamp
+      (DateTime.parse(current_migration_number(dirname).to_s) + 1.second).strftime(format)
+    rescue ArgumentError
+      if ActiveRecord::Base.timestamped_migrations
+        # this will only run the first migration file is generated
+        Time.now.utc.strftime("%Y%m%d%H%M%S").to_i
       else
         "%.3d" % (current_migration_number(dirname) + 1)
       end

lib/generators/drafting/migration/templates/2-metadata_drafting_migration.rb

@@ -0,0 +1,10 @@
+class MetadataDraftingMigration < Drafting::MIGRATION_BASE_CLASS
+  def self.up
+    add_column :drafts, :metadata, :text
+    Draft.reset_column_information
+  end
+
+  def self.down
+    remove_column :drafts, :metadata
+  end
+end

spec/drafting/draft_spec.rb

@@ -20,7 +20,7 @@
     before do
       Draft.delete_all
 
-      message1.save_draft(user)
+      message1.save_draft(user, title: 'Title1')
       message2.save_draft(user)
     end
 

spec/drafting/instance_methods_spec.rb

@@ -77,6 +77,23 @@
       expect(draft.user_id).to eq(admin_user.id)
     end
 
+    it 'should save metadata on draft and allow changes' do
+      message.save_draft(
+        nil,
+        {
+          title: 'Message Title',
+          sub_title: 'Message SubTitle'
+        }
+      )
+      draft = Draft.find(message.draft_id)
+      expect(draft.title).to eq 'Message Title'
+      expect(draft.sub_title).to eq 'Message SubTitle'
+
+      draft.title = 'New Title'
+      draft.save
+      expect(draft.reload.title).to eq 'New Title'
+    end
+
     it 'should store extra attributes to Draft' do
       message.priority = 5
       message.save_draft(user)
@@ -85,7 +102,7 @@
       expect(draft.restore.priority).to eq(5)
     end
 
-    it 'should store assocations to Draft' do
+    it 'should store associations to Draft' do
       message = topic.messages.build user: user, content: 'foo'
       message.tags.build name: 'important'
       message.tags.build name: 'ruby'
@@ -118,7 +135,7 @@
   end
 
   describe 'update_draft' do
-    it 'should update existing Draft object' do
+    it 'should update existing Draft object (without metadata)' do
       message.save_draft(user)
 
       expect {
@@ -129,6 +146,31 @@
       draft = Draft.find(message.draft_id)
       expect(draft.restore.attributes).to eq(message.attributes)
     end
+
+    it 'should update existing Draft object (with metadata)' do
+      message.save_draft(user)
+
+      expect {
+        message.update_draft(
+          user,
+          { content: 'bar' },
+          {
+            title: 'Message Title',
+            sub_title: 'Message SubTitle'
+          }
+        )
+      }.to change(Draft, :count).by(0).and \
+           change(Message, :count).by(0)
+
+      draft = Draft.find(message.draft_id)
+      expect(draft.title).to eq 'Message Title'
+      expect(draft.sub_title).to eq 'Message SubTitle'
+      expect(draft.restore.attributes).to eq(message.attributes)
+
+      draft.title = 'New Title'
+      draft.save
+      expect(draft.reload.title).to eq 'New Title'
+    end
   end
 
   describe 'clear_draft' do