Model Validation

Iris, wisely, not features a builtin data validation. However, it does allow you to attach a validator which will automatically called on methods like Context.ReadJSON, ReadXML.... In this example we will learn how to use the go-playground/validator/v10 for request body validation.
Check the full docs and the struct tags usage here.
1
$ go get github.com/go-playground/validator/[email protected]
Copied!
Note that you need to set the corresponding binding tag on all fields you want to bind. For example, when binding from JSON, set json:"fieldname".
1
package main
2
​
3
import (
4
    "fmt"
5
​
6
    "github.com/kataras/iris/v12"
7
​
8
    "github.com/go-playground/validator/v10"
9
)
10
​
11
// User contains user information.
12
type User struct {
13
    FirstName      string     `json:"fname"`
14
    LastName       string     `json:"lname"`
15
    Age            uint8      `json:"age" validate:"gte=0,lte=130"`
16
    Email          string     `json:"email" validate:"required,email"`
17
    FavouriteColor string     `json:"favColor" validate:"hexcolor|rgb|rgba"`
18
    Addresses      []*Address `json:"addresses" validate:"required,dive,required"`
19
}
20
​
21
// Address houses a users address information.
22
type Address struct {
23
    Street string `json:"street" validate:"required"`
24
    City   string `json:"city" validate:"required"`
25
    Planet string `json:"planet" validate:"required"`
26
    Phone  string `json:"phone" validate:"required"`
27
}
28
​
29
func main() {
30
    // Use a single instance of Validate, it caches struct info.
31
    v := validator.New()
32
​
33
    // Register a custom struct validation for 'User'
34
    // NOTE: only have to register a non-pointer type for 'User', validator
35
    // internally dereferences during it's type checks.
36
    v.RegisterStructValidation(UserStructLevelValidation, User{})
37
​
38
    app := iris.New()
39
    // Register the validator to the Iris Application.
40
    app.Validator = v
41
​
42
    app.Post("/user", func(ctx iris.Context) {
43
        var user User
44
​
45
        // Returns InvalidValidationError for bad validation input,
46
        // nil or ValidationErrors ( []FieldError )
47
        err := ctx.ReadJSON(&user)
48
        if err != nil {
49
            // This check is only needed when your code could produce
50
            // an invalid value for validation such as interface with nil
51
            // value most including myself do not usually have code like this.
52
            if _, ok := err.(*validator.InvalidValidationError); ok {
53
                ctx.StatusCode(iris.StatusInternalServerError)
54
                ctx.WriteString(err.Error())
55
                return
56
            }
57
​
58
            ctx.StatusCode(iris.StatusBadRequest)
59
            for _, err := range err.(validator.ValidationErrors) {
60
                fmt.Println()
61
                fmt.Println(err.Namespace())
62
                fmt.Println(err.Field())
63
                fmt.Println(err.StructNamespace())
64
                fmt.Println(err.StructField())
65
                fmt.Println(err.Tag())
66
                fmt.Println(err.ActualTag())
67
                fmt.Println(err.Kind())
68
                fmt.Println(err.Type())
69
                fmt.Println(err.Value())
70
                fmt.Println(err.Param())
71
                fmt.Println()
72
            }
73
​
74
            return
75
        }
76
​
77
        // [save user to database...]
78
    })
79
​
80
    app.Listen(":8080")
81
}
82
​
83
func UserStructLevelValidation(sl validator.StructLevel) {
84
    user := sl.Current().Interface().(User)
85
​
86
    if len(user.FirstName) == 0 && len(user.LastName) == 0 {
87
        sl.ReportError(user.FirstName, "FirstName", "fname", "fnameorlname", "")
88
        sl.ReportError(user.LastName, "LastName", "lname", "fnameorlname", "")
89
    }
90
}
Copied!
Example request of JSON form:
1
{
2
    "fname": "",
3
    "lname": "",
4
    "age": 45,
5
    "email": "[email protected]",
6
    "favColor": "#000",
7
    "addresses": [{
8
        "street": "Eavesdown Docks",
9
        "planet": "Persphone",
10
        "phone": "none",
11
        "city": "Unknown"
12
    }]
13
}
Copied!
Example can be found at: https://github.com/kataras/iris/tree/master/_examples/request-body/read-json-struct-validation/main.go.

📘Contents - Previous

Forms

Next - 📘Contents

Cache

Last modified 1yr ago

Export as PDF

Copy link