使用 Golang 的 required_if 标记，根据封闭结构字段之一的值验证内部结构字段的方法

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golang版本：1.18.3

验证器：github.com/go-演示/validator/v10

我想在加载到嵌套结构数据结构后验证传入的 json 有效负载。这是我传入的 json 负载，

{
        "irn": 1,
        "firstname": "testing",
        "lastname": "test",
        "cardtype": "reciprocal",
        "number": "2248974514",
        "cardexpiry": {
            "month": "01",
            "year": "2025"
        }
}

这是我的 medicare.go 文件

package main

import (
    "encoding/json"

    "github.com/go-playground/validator/v10"
)

type medicare struct {
    irn           uint8
    firstname     string
    middleinitial string
    lastname      string
    cardtype      string `validate:"required,eq=resident|eq=reciprocal|eq=interim"`
    number        string
    cardexpiry    *cardexpiry `validate:"required"`
}

type cardexpiry struct {
    day   string
    month string `validate:"required"`
    year  string `validate:"required"`
}

这是我的测试函数

func testuserpayload(t *testing.t) {
    var m medicare

    err := json.unmarshal([]byte(jsondata), &m)
    if err != nil {
        panic(err)
    }

    validate := validator.new()
    err = validate.struct(m)
    if err != nil {
        t.errorf("error %v", err)
    }
}

我想使用 validator/v10 的 required_if 标签进行以下验证。 这是验证逻辑，

if (m.cardtype == "reciprocal" || m.cardtype == "interim") &&
    m.cardexpiry.day == "" {
    //validation error
}

required_if 可以根据同一结构中的字段值使用（在本例中为 cardexpiry）

day   string `validate:"required_if=month 01"`

我的问题是，

可以根据其封闭结构字段之一（在本例中为 medicare 结构）的值来完成吗？ 例如：

Day   string `validate:"required_if=Medicare.CardType RECIPROCAL"`

如果可以，如何？

这是演示代码

正确答案

有点老的问题，但是 valix (https://github.com/marrow16/valix) 可以使用条件“开箱即用”地做这样的事情。示例...

package main

import (
    "fmt"
    "net/http"
    "strings"

    "github.com/marrow16/valix"
)

type Medicare struct {
    IRN           uint8  `json:"irn"`
    FirstName     string `json:"firstName"`
    MiddleInitial string `json:"middleInitial"`
    LastName      string `json:"lastName"`
    // set order on this property so that it is evaluated before 'CardExpiry' object is checked...
    // (and set a condition based on its value)
    CardType   string      `json:"cardType" v8n:"order:-1,required,&StringValidToken{['RESIDENT','RECIPROCAL','INTERIM']},&SetConditionFrom{Global:true}"`
    Number     string      `json:"number"`
    CardExpiry *CardExpiry `json:"cardExpiry" v8n:"required,notNull"`
}

type CardExpiry struct {
    // this property is required when a condition of `RECIPROCAL` has been set (and unwanted when that condition has not been set)...
    Day   string `json:"day" v8n:"required:RECIPROCAL,unwanted:!RECIPROCAL"`
    Month string `json:"month" v8n:"required"`
    Year  string `json:"year" v8n:"required"`
}


var medicareValidator = valix.MustCompileValidatorFor(Medicare{}, nil)

func main() {
    jsonData := `{
        "irn": 1,
        "firstName": "Testing",
        "lastName": "Test",
        "cardType": "RECIPROCAL",
        "number": "2248974514",
        "cardExpiry": {
            "month": "01",
            "year": "2025"
        }
    }`

    medicare := &Medicare{}
    ok, violations, _ := medicareValidator.ValidateStringInto(jsonData, medicare)
    // should fail with 1 violation...
    fmt.Printf("First ok?: %v\n", ok)
    for i, v := range violations {
        fmt.Printf("Violation[%d]: Message:%s, Property:%s, Path:%s\n", i+1, v.Message, v.Property, v.Path)
    }

    jsonData = `{
            "irn": 1,
            "firstName": "Testing",
            "lastName": "Test",
            "cardType": "RECIPROCAL",
            "number": "2248974514",
            "cardExpiry": {
                "day": "01",
                "month": "01",
                "year": "2025"
            }
        }`
    ok, _, _ = medicareValidator.ValidateStringInto(jsonData, medicare)
    // should be ok...
    fmt.Printf("Second ok?: %v\n", ok)

    jsonData = `{
            "irn": 1,
            "firstName": "Testing",
            "lastName": "Test",
            "cardType": "INTERIM",
            "number": "2248974514",
            "cardExpiry": {
                "month": "01",
                "year": "2025"
            }
        }`
    ok, _, _ = medicareValidator.ValidateStringInto(jsonData, medicare)
    // should be ok...
    fmt.Printf("Third ok?: %v\n", ok)

    jsonData = `{
            "irn": 1,
            "firstName": "Testing",
            "lastName": "Test",
            "cardType": "INTERIM",
            "number": "2248974514",
            "cardExpiry": {
                "day": "01",
                "month": "01",
                "year": "2025"
            }
        }`
    ok, violations, _ = medicareValidator.ValidateStringInto(jsonData, medicare)
    fmt.Printf("Fourth ok?: %v\n", ok)
    for i, v := range violations {
        fmt.Printf("Violation[%d]: Message:%s, Property:%s, Path:%s\n", i+1, v.Message, v.Property, v.Path)
    }

    // or validate directly from a http request...
    req, _ := http.NewRequest("POST", "", strings.NewReader(jsonData))
    ok, violations, _ = medicareValidator.RequestValidateInto(req, medicare)
    fmt.Printf("Fourth (as http.Request) ok?: %v\n", ok)
    for i, v := range violations {
        fmt.Printf("Violation[%d]: Message:%s, Property:%s, Path:%s\n", i+1, v.Message, v.Property, v.Path)
    }
}

go-playground

披露：我是 valix 的作者

你可以编写自定义验证， playground-solution，自定义验证的文档可在此处获取 https://pkg.go.dev/github.com/go-演示/validator#customtypefunc。

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