go panic - No data received - ERR_EMPTY_RESPONSE - http

Question

I'm using gorethink driver, I write a query function like this in model
func GetQuotesByUser(idUser string) []Quote{
ids:=GetQuoteIdsByUser(idUser)
if (len(ids)>0){
result,err:=r.Table("quote").GetAll(ids...).Run(config.Connection())
defer result.Close()
if err!=nil{
fmt.Println(err)
return []Quote{}
}
var quotes []Quote
err=result.All(&quotes)
if err!=nil{
fmt.Println(err)
return []Quote{}
}
fmt.Println(quotes)
return quotes
} else{
return []Quote{}
}
}
I write a route handler that calls the above function
import (
"corate/util"
"corate/model"
"github.com/fatih/structs"
"net/http"
)
func DashboardHandler(w http.ResponseWriter,r *http.Request){
files:=[]string{"base","dashboard"}
session,_:=util.GlobalSessions.SessionStart(w,r)
defer session.SessionRelease(w)
quotes:=model.GetQuotesByUser("ca8a2e14-f65b-43b1-b655-97d7c29190ec")
q:=structs.Map(quotes)
util.RenderTemplate(w,q,files...)
}
This is main function
func main(){
// Setup database
config.Setupdb()
// Initialize session manager
util.InitSessionManager()
// Serve static folder
http.Handle("/public/",http.StripPrefix("/public/",http.FileServer(http.Dir("public"))))
// Setup routers and middlewares
http.HandleFunc("/",route.IndexHandler)
http.HandleFunc("/login",route.GoogleLoginHandler)
http.HandleFunc("/auth/google",route.GoogleCallbackHandler)
http.Handle("/dashboard",negroni.New(
negroni.HandlerFunc(route.IsAuthenticated),
negroni.Wrap(http.HandlerFunc(route.DashboardHandler)),
))
// Start listening
http.ListenAndServe(":3000",nil)
}
I use astaxie/beego/session library to manage sessions for this server
import (
"github.com/astaxie/beego/session"
)
var (
GlobalSessions *session.Manager
)
func InitSessionManager() {
GlobalSessions, _ = session.NewManager("memory", `{"cookieName":"gosessionid","gclifetime":3600}`)
go GlobalSessions.GC()
}
When I start the server, and login and request to dashboard path, DashboardHandler is processed,GetQuotesByUser is called, and it works, it works, it does print out true results of query. But in browser, the browser throws error:
No data received
ERR_EMPTY_RESPONSE
The console logs some errors as well
http: panic serving 127.0.0.1:51229: not struct
goroutine 84 [running]:
net/http.(*conn).serve.func1(0xc82015fc00)
/home/kuro/.gvm/gos/go1.6/src/net/http/server.go:1389 +0xc1
panic(0x7f58e0, 0xc8204489f0)
/home/kuro/.gvm/gos/go1.6/src/runtime/panic.go:426 +0x4e9
github.com/fatih/structs.strctVal(0x7de700, 0xc82045a340, 0x0, 0x0, 0x0)
/home/kuro/Workspace/Go/src/github.com/fatih/structs/structs.go:426 +0x136
github.com/fatih/structs.New(0x7de700, 0xc82045a340, 0x0)
/home/kuro/Workspace/Go/src/github.com/fatih/structs/structs.go:30 +0x2f
github.com/fatih/structs.Map(0x7de700, 0xc82045a340, 0xc82045a340)
/home/kuro/Workspace/Go/src/github.com/fatih/structs/structs.go:435 +0x2b
corate/route.DashboardHandler(0x7fe2c2e6dfc8, 0xc8202d49c0, 0xc820372460)
/home/kuro/Workspace/Go/src/corate/route/user.go:19 +0x190
net/http.HandlerFunc.ServeHTTP(0xa47820, 0x7fe2c2e6dfc8, 0xc8202d49c0, 0xc820372460)
/home/kuro/.gvm/gos/go1.6/src/net/http/server.go:1618 +0x3a
github.com/codegangsta/negroni.Wrap.func1(0x7fe2c2e6dfc8, 0xc8202d49c0, 0xc820372460, 0xc8203f0a60)
/home/kuro/Workspace/Go/src/github.com/codegangsta/negroni/negroni.go:41 +0x50
github.com/codegangsta/negroni.HandlerFunc.ServeHTTP(0xc82012ace0, 0x7fe2c2e6dfc8, 0xc8202d49c0, 0xc820372460, 0xc8203f0a60)
/home/kuro/Workspace/Go/src/github.com/codegangsta/negroni/negroni.go:24 +0x44
github.com/codegangsta/negroni.middleware.ServeHTTP(0x7fe2c2e6ade0, 0xc82012ace0, 0xc82012ad40, 0x7fe2c2e6dfc8, 0xc8202d49c0, 0xc820372460)
/home/kuro/Workspace/Go/src/github.com/codegangsta/negroni/negroni.go:33 +0xaa
github.com/codegangsta/negroni.(middleware).ServeHTTP-fm(0x7fe2c2e6dfc8, 0xc8202d49c0, 0xc820372460)
/home/kuro/Workspace/Go/src/github.com/codegangsta/negroni/negroni.go:33 +0x53
corate/route.IsAuthenticated(0x7fe2c2e6dfc8, 0xc8202d49c0, 0xc820372460, 0xc8203f0a00)
/home/kuro/Workspace/Go/src/corate/route/isAuthenticated.go:14 +0x174
github.com/codegangsta/negroni.HandlerFunc.ServeHTTP(0xa47840, 0x7fe2c2e6dfc8, 0xc8202d49c0, 0xc820372460, 0xc8203f0a00)
/home/kuro/Workspace/Go/src/github.com/codegangsta/negroni/negroni.go:24 +0x44
github.com/codegangsta/negroni.middleware.ServeHTTP(0x7fe2c2e6ade0, 0xa47840, 0xc82012ad20, 0x7fe2c2e6dfc8, 0xc8202d49c0, 0xc820372460)
/home/kuro/Workspace/Go/src/github.com/codegangsta/negroni/negroni.go:33 +0xaa
github.com/codegangsta/negroni.(*Negroni).ServeHTTP(0xc8200cfe90, 0x7fe2c2e6af70, 0xc820154680, 0xc820372460)
/home/kuro/Workspace/Go/src/github.com/codegangsta/negroni/negroni.go:73 +0x122
net/http.(*ServeMux).ServeHTTP(0xc820013740, 0x7fe2c2e6af70, 0xc820154680, 0xc820372460)
/home/kuro/.gvm/gos/go1.6/src/net/http/server.go:1910 +0x17d
net/http.serverHandler.ServeHTTP(0xc82000e380, 0x7fe2c2e6af70, 0xc820154680, 0xc820372460)
/home/kuro/.gvm/gos/go1.6/src/net/http/server.go:2081 +0x19e
net/http.(*conn).serve(0xc82015fc00)
/home/kuro/.gvm/gos/go1.6/src/net/http/server.go:1472 +0xf2e
created by net/http.(*Server).Serve
/home/kuro/.gvm/gos/go1.6/src/net/http/server.go:2137 +0x44e
Why does it happen? Then I notice that if I don't utilize fatih/structs library, nothing will go wrong. But I want to use that library, it will help me much. I want to know reason of this strange behavior and how to fix it while still using fatih/structs library

Answer 1

GetQuotesByUser returns a slice, not a struct. So you can't pass it directly to structs.Map. You'll have to iterate the slice and convert each element to a map individually.
quotes := model.GetQuotesByUser("ca8a2e14-f65b-43b1-b655-97d7c29190ec")
qs := []map[string]interface{}{}
for _, q := range quotes {
qs = append(qs, structs.Map(q))
}
util.RenderTemplate(w,qs,files...)
Should get you close to what you're after.