Question

我的任务是编写一个函数来验证下面代码中的名字和姓氏是不一样的。我必须使用ActiveModel :: Validation和ActiveModel :: Errors，如果两个名称相同，则应该给出错误消息“Nope”。

我的红宝石体验很少，但这是我的尝试：

require 'active_model'

class Person
    include ActiveModel::Validations
    validate :test
    validates_presence_of :first
    validates_presence_of :last

    def initialize(first, last)
        @first = first
        @last = last
    end

    def test
        errors.add_to_base("Nope") if @first == @last
    end

end

a = Person.new("James", "James")
b = Person.new("James")

因此，当我尝试实例化b时，我收到一条错误消息，但这只是一个Ruby错误，因为我的函数缺少参数。我相信这可能很简单，但我真的很感激任何帮助。

Answer 1

查看https://github.com/rails/rails/tree/master/activemodel了解详情：

require 'active_model'

class TestValidator < ActiveModel::Validator
  def validate(record)
    record.errors[:base] = "First and last can't be the same" if record.first.presence == record.last.presence
  end
end

class Person
    include ActiveModel::Model

    attr_accessor :first, :last

    validates_presence_of :first, :last
    validates_with TestValidator
end

p = Person.new(first: "Nick", last: "Nick")
puts p.valid? # => false
puts p.errors.full_messages # => First and last can't be the same

p = Person.new(first: "Nick", last: "Doe")
puts p.valid? # => true

Answer 2

我想出了我自己的解决方案，我一直在寻找：

require 'active_model'

class Person
include ActiveModel::Validations
attr_accessor :first, :last
validate :first_does_not_equal_last

def first_does_not_equal_last
  if @first == @last
    self.errors[:base] << "First cannot be the same as Last"
  end
end

def initialize(first, last)
    @first = first
    @last = last
end

end

Ruby ActiveModel :: Validation和ActiveModel :: Errors设置函数用于验证

2 个答案: