Golang解析形式

Question

If I have the following form setup:

{{ range $key, $value := .Scores }}
    <input id="{{$value.Id}}_rating__1" type="radio" name="rating[{{$value.Id}}]" value="-1">
    <input id="{{$value.Id}}_rating__0" type="radio" name="rating[{{$value.Id}}]" value="0">
    <input id="{{$value.Id}}_rating__2" type="radio" name="rating[{{$value.Id}}]" value="+1">
{{ end }}

How can I then extract that data correctly? Knowing that there .Scores can contain multiple structs

func categoryViewSubmit(w http.ResponseWriter, r *http.Request) {
    err := r.ParseForm()
    if err != nil {
        log.Fatal(err)
    }
    fmt.Println("POST")

    fmt.Printf("%+v
", r.Form()) // annot call non-function r.Form (type url.Values)
    fmt.Printf("%+v
", r.FormValue("rating")) // Returns nothing
}

Answer 1

The form keys look like rating[id] where id is a value identifier. To get one of the values, call r.FormValue("rating[id]") after substituting id for an actual id value.

I suggest printing the form to see what's going on:

fmt.Printf("%+v
", r.Form)  // No () following Form, Form is not a function

The form is an url.Values. An url.Values is a map[string][]string. You can iterate through the form as follows:

for key, values := range r.Form {   // range over map
  for _, value := range values {    // range over []string
     fmt.Println(key, value)
  }
}