couchrest_model/lib/couchrest/model/validations/uniqueness.rb

54 lines
1.7 KiB
Ruby

# encoding: utf-8
module CouchRest
module Model
module Validations
# Validates if a field is unique
class UniquenessValidator < ActiveModel::EachValidator
# Ensure we have a class available so we can check for a usable view
# or add one if necessary.
def setup(model)
@model = model
end
def validate_each(document, attribute, value)
keys = [attribute]
unless options[:scope].nil?
keys = (options[:scope].is_a?(Array) ? options[:scope] : [options[:scope]]) + keys
end
values = keys.map{|k| document.send(k)}
values = values.first if values.length == 1
view_name = options[:view].nil? ? "by_#{keys.join('_and_')}" : options[:view]
model = (document.respond_to?(:model_proxy) && document.model_proxy ? document.model_proxy : @model)
# Determine the base of the search
base = options[:proxy].nil? ? model : document.instance_eval(options[:proxy])
if base.respond_to?(:has_view?) && !base.has_view?(view_name)
raise "View #{document.class.name}.#{options[:view]} does not exist!" unless options[:view].nil?
model.view_by *keys, :allow_nil => true
end
rows = base.view(view_name, :key => values, :limit => 2, :include_docs => false)['rows']
return if rows.empty?
unless document.new?
return if rows.find{|row| row['id'] == document.id}
end
if rows.length > 0
opts = options.merge(:value => value)
opts.delete(:scope) # Has meaning with I18n!
document.errors.add(attribute, :taken, opts)
end
end
end
end
end
end