Allow multi-database configuration via AR base model selection

app/controllers/rails_db/application_controller.rb

@@ -4,6 +4,7 @@ class ApplicationController < ActionController::Base
     helper_method :per_page
 
     before_action :verify_access
+    before_action :set_abstract_model_class
 
     if RailsDb.http_basic_authentication_enabled
       http_basic_authenticate_with name: RailsDb.http_basic_authentication_user_name,
@@ -21,6 +22,13 @@ def per_page
       params[:per_page] || session[:per_page]
     end
 
+    def set_abstract_model_class
+      return unless params[:abstract_model_class].present?
+
+      if (found = RailsDb.available_abstract_model_classes.find { |klass| klass.name == params[:abstract_model_class] })
+        RailsDb.abstract_model_class = found
+      end
+    end
   end
 end
 

app/views/rails_db/shared/_sidebar.html.erb

@@ -1,3 +1,22 @@
+<% if RailsDb.available_abstract_model_classes.many? %>
+  Do you want to see tables from a specific model base class?
+  <ul>
+    <% RailsDb.available_abstract_model_classes.each do |klass| %>
+      <li>
+        <% if klass == RailsDb.abstract_model_class %>
+          <strong>
+            <%= klass.name %>
+          </strong>
+        <% else %>
+          <%= link_to root_path(abstract_model_class: klass.name) do %>
+            <%= klass.name %>
+          <% end %>
+        <% end %>
+      </li>
+    <% end %>
+  </ul>
+<% end %>
+
 <h3>Tables</h3>
 
 <input id='rails_db_tables_input' placeholder='... quick filter by table name'>

lib/generators/templates/rails_db.rb

@@ -26,5 +26,11 @@
 
     # # Sandbox mode (only read-only operations)
     # config.sandbox = false
+
+    # # Configure to use something else than ActiveRecord::Base
+    # config.abstract_model_class = ApplicationRecord
+
+    # # Configure for multi-database environments to switch base models in the GUI
+    # config.available_abstract_model_classes = [ApplicationRecord, Tenant1::Base, Tenant2::Base]
   end
 end

lib/rails_db.rb

@@ -49,6 +49,14 @@ module RailsDb
   mattr_accessor :verify_access_proc
   @@verify_access_proc = proc { |controller| true }
 
+  ## Switch out the ActiveRecord::Base class by any abstract descendant
+  mattr_accessor :abstract_model_class
+  @@abstract_model_class = ActiveRecord::Base
+
+  ## Configure this in multi-database environments
+  mattr_accessor :available_abstract_model_classes
+  @@available_abstract_model_classes = [ActiveRecord::Base]
+
   def self.setup
     yield(self)
   end
@@ -59,6 +67,8 @@ def self.use_default_configuration!
     self.black_list_tables                  = self.white_list_tables = []
     self.http_basic_authentication_enabled  = false
     self.verify_access_proc                 = proc { |controller| true }
+    self.abstract_model_class               = ActiveRecord::Base
+    self.available_abstract_model_classes   = [ActiveRecord::Base]
   end
 
 end

lib/rails_db/adapters/base_adapter.rb

@@ -8,7 +8,7 @@ class BaseAdapter
 
       def self.execute_with_sandbox_if_needed
         if RailsDb.sandbox
-          ActiveRecord::Base.transaction do
+          RailsDb.abstract_model_class.transaction do
             yield
             raise ActiveRecord::Rollback
           end

lib/rails_db/connection.rb

@@ -2,9 +2,9 @@ module RailsDb
   module Connection
 
     def connection
-      ActiveRecord::Base.connection
+      RailsDb.abstract_model_class.connection
     rescue ActiveRecord::ConnectionNotEstablished
-      ActiveRecord::Base.establish_connection(Rails.application.config.database_configuration[Rails.env]).connection
+      RailsDb.abstract_model_class.establish_connection(Rails.application.config.database_configuration[Rails.env]).connection
     end
 
     def columns

lib/rails_db/table.rb

@@ -48,7 +48,7 @@ def delete(id)
 
     def create_model(table_name, &block)
       begin
-        klass = Class.new(ActiveRecord::Base) do
+        klass = Class.new(RailsDb.abstract_model_class) do
           def self.model_name
             ActiveModel::Name.new(self, nil, table_name)
           end
@@ -57,7 +57,7 @@ def self.model_name
         end
         klass.count # verify that it works, if not load other, hack
       rescue
-        klass = ActiveRecord::Base.descendants.detect { |c| c.table_name == table_name }
+        klass = RailsDb.abstract_model_class.descendants.detect { |c| c.table_name == table_name }
       end
 
       add_ransack_methods(klass) if ransack_version >= Gem::Version.new('4.0.0')