2018-07-16-理解错误消息

errors 对象

errors 是一个错误对象；
大概长这样

#<ActiveModel::Errors:0x007fe10b7d16a0 @base=#<User id: nil, name: nil, address: nil, age: nil, created_at: nil, updated_at: nil, home_page_urls: nil, terms_of_service: nil, email: nil, alisa_name: nil, role: nil, length_of_service: nil>, @messages={:name=>["名字不能为空", "名字只能是3-8位"], :alisa_name=>["别名只能为四位"], :email_confirmation=>["确认邮箱不能为空"], :email=>["必须输入邮箱格式", "%{value}不是一个邮箱"]}, @details={:name=>[{:error=>:blank}, {:error=>:too_short, :count=>3}], :alisa_name=>[{:error=>:wrong_length, :count=>4}], :email_confirmation=>[{:error=>:blank}], :email=>[{:error=>:invalid, :value=>nil}]}>

errors.messages 错误消息hash

1、键是 字段，每个字段的错误消息 是值
2、值装在数组中
大概这样

{
                  :name => [
        [0] "名字不能为空",
        [1] "名字只能是3-8位"
    ],
            :alisa_name => [
        [0] "别名只能为四位"
    ],
    :email_confirmation => [
        [0] "确认邮箱不能为空"
    ],
                 :email => [
        [0] "必须输入邮箱格式",
        [1] "%{value}不是一个邮箱"
    ]
}

errors.full_messages 将字段和错误信息组合

便于页面显示，它是一个数组

[
    [0] "Name 名字不能为空",
    [1] "Name 名字只能是3-8位",
    [2] "Alisa name 别名只能为四位",
    [3] "Email confirmation 确认邮箱不能为空",
    [4] "Email 必须输入邮箱格式",
    [5] "Email %{value}不是一个邮箱"
]

errors[:name] 取出单个字段的错误消息

image.png

向errors中添加错误消息

1、errors.add(:name,'message')常用写法
2、errors[:name] << 'message'和上等价
3、errors.messages[:name] << 'message' 等价

4、errors[:base] << 'message' 对于对象的错误信息，非字段装到base中

errors.clear 清空错误消息

errors.details查看错误键 hash

{
                  :name => [
        [0] {
            :error => :blank
        },
        [1] {
            :error => :too_short,
            :count => 3
        }
    ],
            :alisa_name => [
        [0] {
            :error => :wrong_length,
            :count => 4
        }
    ],
    :email_confirmation => [
        [0] {
            :error => :blank
        }
    ],
                 :email => [
        [0] {
            :error => :invalid,
            :value => nil
        }
    ]
}