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@eiwi1101
Created December 12, 2016 17:24
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HasGuid a concern for automatically adding and maintaining a GUID/UUID/Token etc on your objects.
module HasGuid
extend ActiveSupport::Concern
included do
before_validation :generate_guid
class_attribute :guid_column_name
class_attribute :guid_options
validate :validate_guid
self.guid_column_name = :guid
self.guid_options = {}
end
def to_param
self.send(self.guid_column_name)
end
module ClassMethods
# Assigns a GUID on +guid_column_name+ which will be unique within global scope and created before validation.
#
# Options:
# +scope+ (Symbol) - The scope of uniqueness to ensure.
# +type+ (String) - One of 'token', 'uuid' or nil for default (hex string)
# +length+ (Integer) - The length of the GUID to generate. Not valid for UUID
#
def has_guid(guid_column_name=:guid, options={})
self.guid_column_name = guid_column_name
self.guid_options = options
end
def find(id)
if id.is_a? String
self.find_by!(self.guid_column_name => id)
else
self.find_by!(id: id)
end
end
end
private
def guid_scope
guid_options[:scope] ? {guid_options[:scope] => self.send(guid_options[:scope])} : '1=1'
end
def generate_guid
return true unless self.send(guid_column_name).blank?
begin
guid = case guid_options[:type]&.to_s
when 'token'
SecureRandom.urlsafe_base64(guid_options[:length] || 8)
when 'uuid'
SecureRandom.uuid
else
SecureRandom.hex(guid_options[:length] || 8)
end
self.assign_attributes(guid_column_name => guid)
end while self.class.where(guid_scope).exists?(guid_column_name => self.send(guid_column_name))
true
end
def validate_guid
if self.send(guid_column_name).blank?
self.errors[guid_column_name] << "can't be blank"
end
if self.class.where(guid_scope).where.not(id: self.id).exists?(guid_column_name => self.send(guid_column_name))
self.errors[guid_column_name] << 'has already been taken'
end
self.errors[guid_column_name].any?
end
end
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