package main import ( "io" "gopkg.in/kataras/iris.v6" "gopkg.in/kataras/iris.v6/adaptors/httprouter" ) func main() { app := iris.New() // output startup banner and error logs on os.Stdout app.Adapt(iris.DevLogger()) // set the router, you can choose gorillamux too app.Adapt(httprouter.New()) // Custom Render Policy to override or create new content-type render // i,e: "text/html" with a prefix, // we will just write to the writer and return false // to continue to the next contentType-matched renderer if any. app.Adapt(iris.RenderPolicy(func(out io.Writer, contentType string, binding interface{}, options ...map[string]interface{}) (bool, error) { if contentType == "text/html" { if content, ok := binding.(string); ok { out.Write([]byte("
My Custom prefix

" + content)) } } // continue to the next, no error // note: if we wanted to stop here we would return true instead of false. return false, nil })) app.Get("", func(ctx *iris.Context) { // These content-types are not managed by our RenderPolicy: // text, binary and html content-types are // not rendered via serializers, you have to // use the ctx.Render functions instead. // so something like this: // ctx.Text(iris.StatusOK, "my text content body here!") // will NOT work with out custom render policy. ctx.Render("text/html", "my text content body here!") }) app.Listen(":8080") }