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

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2010-06-23 11:58:35 +02:00
# 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
if options[:view].blank?
attributes.each do |attribute|
opts = merge_view_options(attribute)
if model.respond_to?(:has_view?) && !model.has_view?(opts[:view_name])
opts[:keys] << {:allow_nil => true}
model.view_by(*opts[:keys])
end
end
end
end
def validate_each(document, attribute, value)
opts = merge_view_options(attribute)
values = opts[:keys].map{|k| document.send(k)}
values = values.first if values.length == 1
model = (document.respond_to?(:model_proxy) && document.model_proxy ? document.model_proxy : @model)
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# Determine the base of the search
base = opts[:proxy].nil? ? model : document.instance_eval(opts[:proxy])
if base.respond_to?(:has_view?) && !base.has_view?(opts[:view_name])
raise "View #{document.class.name}.#{opts[:view_name]} does not exist for validation!"
end
rows = base.view(opts[: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
private
def merge_view_options(attr)
keys = [attr]
keys.unshift(*options[:scope]) unless options[:scope].nil?
view_name = options[:view].nil? ? "by_#{keys.join('_and_')}" : options[:view]
options.merge({:keys => keys, :view_name => view_name})
end
end
end
end
end