improve support for optimistic locking

hidden field for locking column is added automatically in base_form for update action, and any other action which has add_locking_column setting, or if partial is rendered passing add_locking_column in locals.

on_stale_object_error is called in update action when StaleObjectError exception is rescued

CHANGELOG.rdoc

@@ -1,5 +1,7 @@
-- Add css_class to action links, to avoid changing name, it may result confusing, deprecate name setter
-- Add buttons to check all and uncheck all on :select form ui for collection associations, and draggable lists (active_scaffold_checkbox_list)
+- Add css_class to action links, to avoid changing name, it may result confusing, deprecate name setter.
+- Add buttons to check all and uncheck all on :select form ui for collection associations, and draggable lists (active_scaffold_checkbox_list).
+- Add hidden field with locking column in base_form partial for persisted records automatically, if model uses optimistic locking.
+- Add on_stale_object_error when StaleObjectError is rescued, to allow customization.
 
 = 3.7.8
 - Rollback previous behaviour when submitting empty values, broken when default_value was added. Default value set in column is not used when trying to save empty value, DB default is used in that case, and save NULL when string is empty, as before.

app/views/active_scaffold_overrides/_base_form.html.erb

@@ -8,7 +8,10 @@
      columns ||= action_config.columns unless local_assigns.has_key? :columns
      persistent ||= action_config.persistent unless local_assigns.has_key? :persistent
      unless local_assigns.has_key? :floating_footer
-       floating_footer ||= action_config.floating_footer if action_config.respond_to? :floating_footer
+       floating_footer = action_config.floating_footer if action_config.respond_to? :floating_footer
+     end
+     unless local_assigns.has_key? :add_locking_column
+       add_locking_column = action_config.add_locking_column if action_config.respond_to? :add_locking_column
      end
    else
      multipart ||= false
@@ -39,7 +42,7 @@ else
   form_tag url_options, options
 end
 -%>
-
+  <%= hidden_field :record, @record.class.locking_column if add_locking_column && @record.persisted? && @record.locking_enabled? %>
   <h4><%= headline -%></h4>
 
   <div id="<%= element_messages_id(:action => form_action) %>" class="messages-container">

lib/active_scaffold/actions/update.rb

@@ -130,6 +130,7 @@ def update_save(attributes: params[:record], no_record_param_update: false)
     rescue ActiveRecord::StaleObjectError
       @record.errors.add(:base, as_(:version_inconsistency))
       self.successful = false
+      on_stale_object_error(@record)
     rescue ActiveRecord::RecordNotSaved => exception
       logger.warn do
         "\n\n#{exception.class} (#{exception.message}):\n    " +
@@ -201,6 +202,9 @@ def before_update_save(record); end
     # override this method if you want to do something after the save
     def after_update_save(record); end
 
+    # override this method if you want to do something when stale object error is raised
+    def on_stale_object_error(record); end
+
     # should we refresh whole list after update operation
     def update_refresh_list?
       active_scaffold_config.update.refresh_list

lib/active_scaffold/attribute_params.rb

@@ -49,6 +49,12 @@ def multi_parameter_attributes(attributes)
       end
     end
 
+    def assign_locking_column(parent_record, attributes)
+      return unless parent_record.persisted? && parent_record.locking_enabled? &&
+        attributes.include?(parent_record.class.locking_column)
+      parent_record.write_attribute parent_record.class.locking_column, attributes[parent_record.class.locking_column]
+    end
+
     # Takes attributes (as from params[:record]) and applies them to the parent_record. Also looks for
     # association attributes and attempts to instantiate them as associated objects.
     #
@@ -59,6 +65,7 @@ def update_record_from_params(parent_record, columns, attributes, avoid_changes
       return parent_record unless parent_record.authorized_for?(:crud_type => crud_type)
 
       multi_parameter_attrs = multi_parameter_attributes(attributes)
+      assign_locking_column(parent_record, attributes)
 
       columns.each_column(for: parent_record, crud_type: crud_type, flatten: true) do |column|
         # Set any passthrough parameters that may be associated with this column (ie, file column "keep" and "temp" attributes)

lib/active_scaffold/config/update.rb

@@ -4,6 +4,7 @@ class Update < ActiveScaffold::Config::Form
     def initialize(core_config)
       super
       self.nested_links = self.class.nested_links
+      self.add_locking_column = self.class.add_locking_column
     end
 
     # global level configuration
@@ -21,20 +22,25 @@ def self.link=(val)
     cattr_accessor :nested_links, instance_accessor: false
     @@nested_links = false
 
+    cattr_accessor :add_locking_column, instance_accessor: false
+    @@add_locking_column = true
+
     columns_accessor :columns, :copy => :create
 
     # instance-level configuration
     # ----------------------------
 
     attr_accessor :nested_links
 
+    attr_accessor :add_locking_column
+
     attr_writer :hide_nested_column
     def hide_nested_column
       @hide_nested_column.nil? ? true : @hide_nested_column
     end
 
     UserSettings.class_eval do
-      user_attr :nested_links, :hide_nested_column
+      user_attr :nested_links, :hide_nested_column, :add_locking_column
     end
   end
 end