golang parse POST request

Question

I have a HTTP POST request with payload

indices=0%2C1%2C2

Here is my golang backend code

err := r.ParseForm()
if err != nil {
    http.Error(w, err.Error(), http.StatusInternalServerError)
    return
}
log.Println("r.PostForm", r.PostForm)
log.Println("r.Form", r.Form)

body, err := ioutil.ReadAll(r.Body)
if err != nil {
    http.Error(w, err.Error(), http.StatusInternalServerError)
    return
}
log.Println("r.Body", string(body))

values, err := url.ParseQuery(string(body))
if err != nil {
    http.Error(w, err.Error(), http.StatusInternalServerError)
    return
}
log.Println("indices from body", values.Get("indices"))

Output:

r.PostForm map[]
r.Form map[]
r.Body indices=0%2C1%2C2
indices from body 0,1,2

Why is it that the POST request is not parsed by r.ParseForm(), while manaully parsing it with url.ParseQuery(string(body)) gives the correct result?

are you sending your request with the right content type? it should be `application/x-www-form-urlencoded` — Not_a_Golfer, Oct 16 '15 at 07:28
@Not_a_Golfer thanks. that solved the issue. wonder why it was not mentioned here: http://stackoverflow.com/a/23797348/1472186 — paradite, Oct 16 '15 at 07:43

score 18 · Accepted Answer · answered Oct 16 '15 at 09:54

18

The problem is not in your server code which is fine, but simply that your client, whatever it is, is missing the correct Content-Type header for POST forms. Simply set the header to

Content-Type: application/x-www-form-urlencoded

In your client.

answered Oct 16 '15 at 09:54

Not_a_Golfer

47,012
14
126
92

Same thing when you're working with XML / JSON. If your request is sending json always set the header ``Content-Type: application/json``. Same for XML. Its a very good practice, (and sometimes mandatory), to configure the request according to its content to avoid backends the need to "guess" what's processing. – Federico Leon Apr 27 '17 at 20:14

yaziedda · Answer 2 · 2016-10-12T11:16:27.207

8

Get value form your params use PostFormValue("params") from your http.Request

err := r.ParseForm() 
if err != nil{
       panic(err)
}

params := r.PostFormValue("params") // to get params value with key

edited Oct 12 '16 at 11:16

answered Oct 12 '16 at 11:10

yaziedda

111
1
7

golang parse POST request

2 Answers2