Content Negotiation

Learn how to implement content negotiation in Iris.

Basic Content Negotiation

package main

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

type User struct {
    Name string `json:"name" xml:"name"`
    Age  int    `json:"age" xml:"age"`
}

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

    app.Get("/user", func(ctx iris.Context) {
        user := User{
            Name: "John Doe",
            Age:  25,
        }

        ctx.Negotiation().JSON().XML()
        ctx.Negotiate(user)
    })

    app.Listen(":8080")
}

Multiple Formats

app.Get("/data", func(ctx iris.Context) {
    data := iris.Map{
        "message": "Hello World",
    }

    ctx.Negotiation().
        JSON().
        XML().
        YAML().
        MsgPack().
        Any("text/plain", func(ctx iris.Context) {
            ctx.Text("Plain text response")
        })

    ctx.Negotiate(data)
})

Custom Negotiation

app.Get("/custom", func(ctx iris.Context) {
    data := getData()

    ctx.Negotiation().
        JSON(func(ctx iris.Context) {
            ctx.JSON(data)
        }).
        XML(func(ctx iris.Context) {
            ctx.XML(data)
        }).
        MsgPack(func(ctx iris.Context) {
            ctx.MessagePack(data)
        })

    ctx.Negotiate(nil)
})

Best Practices

1. Implementation:

   • Support common formats
   • Handle preferences
   • Set proper headers
   • Document formats
   • Handle errors

2. Performance:

   • Cache responses
   • Monitor usage
   • Handle timeouts
   • Optimize encoding
   • Regular cleanup

3. Headers:

   • Set content type
   • Handle accept header
   • Configure caching
   • Monitor support
   • Handle errors

4. Maintenance:

   • Document formats
   • Update handlers
   • Regular testing
   • Monitor changes
   • Review performance