如何获取ActiveRecord属性方法功能？我有这堂课：
class PurchaseForm
include ActiveModel::Validations
include ActiveModel::Conversion
extend ActiveModel::Naming
attr_accessor :name,:surname,:email
validates_presence_of :name
validates_format_of :email,:with => /^[-a-z0-9_+\.]+\@([-a-z0-9]+\.)+[a-z0-9]{2,4}$/i
def initialize(attributes = {},shop_name)
if not attributes.nil?
attributes.each do |name,value|
send("#{name}=",value)
end
end
def persisted?
false
end
end
解决方法
这是重构的变体：
class PurchaseForm
include ActiveModel::Model
def self.attributes
[:name,:email]
end
attr_accessor *self.attributes
# your validations
def to_hash
self.class.attributes.inject({}) do |hash,key|
hash.merge({ key => self.send(key) })
end
end
end
现在您可以轻松使用此类：
irb(main):001:0> a = PurchaseForm.new({ name: 'Name' })
=> #<PurchaseForm:0x00000002606b50 @name="Name">
irb(main):002:0> a.to_hash
=> {:name=>"Name",:surname=>nil,:email=>nil}
irb(main):003:0> a.email = 'user@example.com'
=> "user@example.com"
irb(main):004:0> a
=> #<PurchaseForm:0x00000002606b50 @name="Name",@email="user@example.com">
irb(main):005:0> a.to_hash
=> {:name=>"Name",:email=>"user@example.com"}
更重要的是,如果要使此行为可重用,请考虑将.attributes和#to_hash方法提取到单独的模块中：
module AttributesHash
extend ActiveSupport::Concern
class_methods do
def attr_accessor(*args)
@attributes = args
super(*args)
end
def attributes
@attributes
end
end
included do
def to_hash
self.class.attributes.inject({}) do |hash,key|
hash.merge({ key => self.send(key) })
end
end
end
end
现在,只需将它包含在您的模型中即可完成：
class PurchaseForm include ActiveModel::Model include AttributesHash attr_accessor :name,:email # your validations end