// Server push lets the server preemptively "push" website assets
// to the client without the user having explicitly asked for them.
// When used with care, we can send what we know the user is going
// to need for the page they're requesting.
package main
import (
"net/http"
"github.com/kataras/iris/v12"
)
func main() {
app := iris.New()
app.Get("/", pushHandler)
app.Get("/main.js", simpleAssetHandler)
app.Run(iris.TLS("127.0.0.1:443", "mycert.crt", "mykey.key"))
// $ openssl req -new -newkey rsa:4096 -x509 -sha256 \
// -days 365 -nodes -out mycert.crt -keyout mykey.key
}
func pushHandler(ctx iris.Context) {
// The target must either be an absolute path (like "/path") or an absolute
// URL that contains a valid host and the same scheme as the parent request.
// If the target is a path, it will inherit the scheme and host of the
// parent request.
target := "/main.js"
if pusher, ok := ctx.ResponseWriter().Naive().(http.Pusher); ok {
err := pusher.Push(target, nil)
if err != nil {
if err == iris.ErrPushNotSupported {
ctx.StopWithText(iris.StatusHTTPVersionNotSupported, "HTTP/2 push not supported.")
} else {
ctx.StopWithError(iris.StatusInternalServerError, err)
}
return
}
}
ctx.HTML(`<html><body><script src="%s"></script></body></html>`, target)
}
func simpleAssetHandler(ctx iris.Context) {
ctx.ServeFile("./public/main.js")
}