Add sequential_id to calculate auto incrementing submission id

Gemfile

@@ -28,6 +28,7 @@ gem 'aws-sdk-s3', require: false
 gem 'google-api-client'
 gem 'rack-cors'
 gem 'sentry-raven'
+gem 'sequenced'
 
 group :development, :test do
   # Call 'byebug' anywhere in the code to stop execution and get a debugger console

Gemfile.lock

@@ -197,6 +197,9 @@ GEM
     semantic_range (2.3.0)
     sentry-raven (3.0.0)
       faraday (>= 1.0)
+    sequenced (3.2.0)
+      activerecord (>= 3.0)
+      activesupport (>= 3.0)
     signet (0.14.0)
       addressable (~> 2.3)
       faraday (>= 0.17.3, < 2.0)
@@ -250,6 +253,7 @@ DEPENDENCIES
   rails
   sass-rails
   sentry-raven
+  sequenced
   spring
   spring-watcher-listen
   turbolinks

app/models/submission.rb

@@ -2,6 +2,8 @@ class Submission < ApplicationRecord
   belongs_to :form
   has_many_attached :files
 
+  acts_as_sequenced scope: :form_id
+
   validates_presence_of :data, if: :appended_at?
 
   def process_data(submitted_data)
@@ -21,6 +23,10 @@ class Submission < ApplicationRecord
       JSON.dump(value)
     when 'tinyforms_now'
       Time.now.utc.to_formatted_s(:rfc822)
+    when 'tinyforms_token'
+      form.token
+    when 'tinyforms_id'
+      sequential_id
     when ActionDispatch::Http::UploadedFile
       # manually create the ActiveStorage attachment because we need the ID of the Attachment to create the URL
       # first the file needs to be uplaoded then we can create an Attachment

db/migrate/20200412165834_add_sequential_id_to_submissions.rb

@@ -0,0 +1,5 @@
+class AddSequentialIdToSubmissions < ActiveRecord::Migration[6.0]
+  def change
+    add_column :submissions, :sequential_id, :integer
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2020_04_09_001610) do
+ActiveRecord::Schema.define(version: 2020_04_12_165834) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -63,6 +63,7 @@ ActiveRecord::Schema.define(version: 2020_04_09_001610) do
     t.datetime "updated_at", precision: 6, null: false
     t.string "remote_ip"
     t.string "referrer"
+    t.integer "sequential_id"
   end
 
   create_table "users", force: :cascade do |t|