go - Golang: redirect twice and cause http: multiple response.WriteHeader calls -

i have weird output ... let me post code first explain:

under main function declared

managemux.handlefunc("/info", info) 

first log in , redirect "/login" page "/":

func login(w http.responsewriter, r *http.request) {     if r.method == "get" {         t, err := template.parsefiles("manage/login.html")         checkerror(err)         t.execute(w, nil)     } else { //post         r.parseform()         //do authentications here         http.redirect(w, r, "/", http.statusfound)     } } 

then redirect page "/info" current page "/" (which has buttons):

func manage(w http.responsewriter, r *http.request) {     t, err := template.parsefiles("manage/manage.html")     checkerror(err)     t.execute(w, nil)     r.parseform()     if r.form["button"] != nil { //to post actions buttons         if r.form["button"][0] == "log" {             http.redirect(w, r, "/info", http.statusfound)         }      } } 

at last, made template , show on client side:

const tpl=`stuff inside`  type infodefault struct {     //stuff inside }  func info(w http.responsewriter, r *http.request) {     info := infodefault{         //stuff inside     }      t, err := template.new("info").parse(tpl)     checkerror(err)     err = t.execute(os.stdout, info)     checkerror(err) } 

now, weird thing is, when click button on page "/", got error "http: multiple response.writeheader calls". @ same time link called "found" shows on bottom of page (weird!), , when click link "found", got parsed template printed on server side instead of webpage.

does know why...? , how fix error , print stuff on client webpage? thank you!!!

as jimb pointed out: server gets confused because there different status codes associated both writing http.responsewriter , redirect. can't both @ same time.

i expand more on how can carry data on next page (assuming redirecting).

headers can write information request object , receive on destination page. example:

func myhandler(w http.responsewriter, r *http.request) {     w.header().set("my-awesome-header", "rocks")     ... } 

session: talking access control far can see, , think persisting user data better done through session. example: can use database or session handler https://github.com/gorilla/sessions. check out thread: best practice sessions (gorilla/sessions).

cookies: i'm not sure kind of front-end using, storing non-sensitive data on cookie option? nothing beats 1 (it has real choc-chip cookies in examples ;-) ): https://astaxie.gitbooks.io/build-web-application-with-golang/content/en/06.1.html.