Class: ActiveRecord::Validations::UniquenessValidator

Inherits:
ActiveModel::EachValidator
  • Object
show all
Defined in:
lib/active_record/validations/uniqueness.rb

Instance Method Summary collapse

Constructor Details

#initialize(options) ⇒ UniquenessValidator

Returns a new instance of UniquenessValidator.



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# File 'lib/active_record/validations/uniqueness.rb', line 6

def initialize(options)
  super(options.reverse_merge(:case_sensitive => true))
end

Instance Method Details

#setup(klass) ⇒ Object

Unfortunately, we have to tie Uniqueness validators to a class.



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# File 'lib/active_record/validations/uniqueness.rb', line 11

def setup(klass)
  @klass = klass
end

#validate_each(record, attribute, value) ⇒ Object 



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# File 'lib/active_record/validations/uniqueness.rb', line 15

def validate_each(record, attribute, value)
  finder_class = find_finder_class_for(record)
  table = finder_class.unscoped

  table_name   = record.class.quoted_table_name

  if value && record.class.serialized_attributes.key?(attribute.to_s)
    value = YAML.dump value
  end

  sql, params  = mount_sql_and_params(finder_class, table_name, attribute, value)

  relation = table.where(sql, *params)

  Array.wrap(options[:scope]).each do |scope_item|
    scope_value = record.send(scope_item)
    relation = relation.where(scope_item => scope_value)
  end

  unless record.new_record?
    # TODO : This should be in Arel
    relation = relation.where("#{record.class.quoted_table_name}.#{record.class.primary_key} <> ?", record.send(:id))
  end

  if relation.exists?
    record.errors.add(attribute, :taken, options.except(:case_sensitive, :scope).merge(:value => value))
  end
end