Module: UpdateCardinalsBy

Extended by:
ActiveSupport::Concern
Defined in:
lib/update_cardinals_by.rb,
lib/update_cardinals_by/version.rb

Constant Summary collapse

VERSION = 
"0.2.0"

Instance Method Summary collapse

Instance Method Details

#update_cardinals_by!(attributes, &block) ⇒ Object

Changes given attributes by delta.

Parameters:

  • attributes, —

    hash from attribute to delta

  • &block —

    Block to execute after making update. Will receive indifferent hash from attribute to latest value in db.



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# File 'lib/update_cardinals_by.rb', line 11

def update_cardinals_by!(attributes, &block)
  db_attributes = attributes.map { |k, v| [self.class.connection.quote_column_name(k), v] }
  updates = db_attributes.map.with_index { |(k, v), i| "#{k} = #{k} + $#{i+1}" }
  binds = attributes.map { |k, v| [column_for_attribute(k), v] }

  transaction do
    res = self.class.connection.exec_query(
      "update #{self.class.table_name} " \
      "set #{updates.join(', ')} " \
      "where id = #{id} " \
      "returning #{db_attributes.map(&:first).join(', ')}",
      'SQL', binds
    ).first
     .map { |k, v| [k, type_for_attribute(k).cast(v)] }
    res = HashWithIndifferentAccess[ res ]

    yield res if block_given?

    res.each do |attr, v|
      write_attribute attr, v
      clear_attribute_change attr
    end
  end
end