JSON Request

Learn how to handle JSON request bodies in Iris.

Basic JSON Handling

package main

import "github.com/kataras/iris/v12"

type User struct {
    ID    int    `json:"id"`
    Name  string `json:"name"`
    Email string `json:"email"`
}

func main() {
    app := iris.New()

    app.Post("/json", func(ctx iris.Context) {
        var user User
        if err := ctx.ReadJSON(&user); err != nil {
            ctx.StopWithError(iris.StatusBadRequest, err)
            return
        }

        ctx.JSON(iris.Map{
            "received": user,
        })
    })

    app.Listen(":8080")
}

JSON Validation

type CreateUser struct {
    Name     string `json:"name" validate:"required,min=2"`
    Email    string `json:"email" validate:"required,email"`
    Age      int    `json:"age" validate:"required,gte=0,lte=130"`
    Password string `json:"password" validate:"required,min=8"`
}

app.Post("/validate", func(ctx iris.Context) {
    var user CreateUser
    if err := ctx.ReadJSON(&user); err != nil {
        ctx.StopWithError(iris.StatusBadRequest, err)
        return
    }

    // Validate struct
    if err := validate.Struct(user); err != nil {
        ctx.StopWithProblem(iris.StatusBadRequest, iris.NewProblem().
            Title("Validation Error").
            DetailErr(err))
        return
    }

    ctx.JSON(iris.Map{
        "message": "JSON validated successfully",
        "user": user,
    })
})

Custom JSON Decoder

app.Post("/custom", func(ctx iris.Context) {
    decoder := json.NewDecoder(ctx.Request().Body)
    decoder.DisallowUnknownFields()

    var data interface{}
    if err := decoder.Decode(&data); err != nil {
        ctx.StopWithError(iris.StatusBadRequest, err)
        return
    }

    ctx.JSON(iris.Map{
        "data": data,
    })
})

Best Practices

1. Validation:

   • Validate schema
   • Check required fields
   • Handle types
   • Set limits
   • Document requirements

2. Security:

   • Validate input
   • Set size limits
   • Check structure
   • Monitor usage
   • Handle errors

3. Performance:

   • Use appropriate decoder
   • Handle large documents
   • Monitor memory
   • Implement timeouts
   • Clean resources

4. Error Handling:

   • Provide clear messages
   • Handle validation errors
   • Log issues
   • Document errors
   • Test edge cases