Add support for Airtable

app/models/form.rb

@@ -1,15 +1,21 @@
-require 'google/apis/sheets_v4'
 class Form < ApplicationRecord
-  # Hash to translate an index to a A1 notation. e.g. 1 => 'B', 27 => 'AA'
-  COLUMN_INDEX_TO_LETTER = Hash.new {|hash,key| hash[key] = hash[key - 1].next }.merge({0 => "A"})
-
   belongs_to :user
   has_many :submissions, dependent: :destroy
+
+  before_validation :insert_defaults, on: :create
   after_create :create_spreadsheet
 
   has_secure_token
 
+  encrypts :airtable_api_key
+  encrypts :airtable_app_key
+
   validates_presence_of :title
+  validates_inclusion_of :backend_name, in: ['google_sheets', 'airtable']
+  # Airtable validations
+  validates_presence_of :airtable_api_key, if: :airtable?
+  validates_presence_of :airtable_app_key, if: :airtable?
+  validates_presence_of :airtable_table, if: :airtable?
 
   # TODO: use counter_cache option on association
   def submissions_count
@@ -28,63 +34,39 @@ class Form < ApplicationRecord
     self.user.active?
   end
 
-  def google_spreadsheet_url
-    "https://docs.google.com/spreadsheets/d/#{google_spreadsheet_id}/edit" if google_spreadsheet_id.present?
+  def airtable?
+    backend_name == 'airtable'
+  end
+
+  def google
+    backend_name == 'google'
+  end
+
+  def backend
+    @backend ||= SpreadsheetBackends.const_get(backend_name.camelize).new(self)
+  end
+
+  def spreadsheet_url
+    backend.url
   end
 
   def create_spreadsheet
-    sheets = Google::Apis::SheetsV4::SheetsService.new
-    sheets.authorization = user.google_authorization
-    create_object = Google::Apis::SheetsV4::Spreadsheet.new(properties: { title: title})
-    spreadsheet = sheets.create_spreadsheet(create_object)
-    update(google_spreadsheet_id: spreadsheet.spreadsheet_id)
+    backend.create
   end
 
-  def spreadsheet_service
-    @spreadsheet_service ||= Google::Apis::SheetsV4::SheetsService.new.tap do |s|
-      s.authorization = user.google_authorization
-    end
+  def append_to_spreadsheet(data)
+    backend.append(data)
   end
 
-  def header_values
-    @header_values ||= begin
-                         values = spreadsheet_service.get_spreadsheet_values(google_spreadsheet_id, 'A1:An').values
-                         # if there are no headers yet, return an empty array
-                         if values
-                          values[0].map(&:strip)
-                         else
-                           []
-                         end
-                       end
-  end
-
-  def append(data)
-    data = data.with_indifferent_access
-    check_spreadsheed_headers!(data)
-
-    values = header_values.map { |key| data[key] }
-    range = "A1:A#{COLUMN_INDEX_TO_LETTER[values.length]}1"
-    value_range = Google::Apis::SheetsV4::ValueRange.new(values: [values], major_dimension: 'ROWS')
-
-    spreadsheet_service.append_spreadsheet_value(google_spreadsheet_id, range, value_range, value_input_option: 'USER_ENTERED')
-  end
-
-  def check_spreadsheed_headers!(data)
-    missing_headers = data.keys.map { |k| k.to_s.strip } - header_values
-    append_missing_headers(missing_headers) unless missing_headers.empty?
-  end
-
-  def append_missing_headers(missing_headers)
-    start_column = COLUMN_INDEX_TO_LETTER[header_values.length]
-    end_column = COLUMN_INDEX_TO_LETTER[header_values.length + missing_headers.length]
-    range = "#{start_column}1:#{end_column}1"
-    value_range = Google::Apis::SheetsV4::ValueRange.new(values: [missing_headers], major_dimension: 'ROWS')
-    spreadsheet_service.update_spreadsheet_value(google_spreadsheet_id, range, value_range, value_input_option: 'USER_ENTERED')
-    @header_values = nil # reset header values to refresh memoization on next access
+  def spreadsheet_headers
+    backend.headers
   end
 
   def to_param
     token
   end
 
+  def insert_defaults
+    self.backend_name ||= airtable_app_key.present? ? 'airtable' : 'google_sheets'
+  end
 end

app/models/submission.rb

@@ -44,7 +44,7 @@ class Submission < ApplicationRecord
   end
 
   def append_to_spreadsheet
-    result = form.append(data)
-    update_column(:appended_at, Time.current) if result.updates.updated_rows > 0
+    form.append_to_spreadsheet(data) &&
+      update_column(:appended_at, Time.current)
   end
 end