Imgur API: POST comment in GO - api

Question

I'm trying to POST a comment to imgur through the Imgur API. But I can't make the payload right. I have looked through Imgur's page about this and they showed that it should be coded like I have in strings.NewReader. The imageID is nP0uKKO
func HandleComment(w http.ResponseWriter, r *http.Request){
parts := strings.Split(r.URL.Path, "/")
switch r.Method {
case "POST":
// URL for POSTing comment
url := "https://api.imgur.com/3/comment"
// Authorization key
token := "Bearer " + os.Getenv("TOKEN")
// Payload
payload := strings.NewReader("------WebKitFormBoundary7MA4YWxkTrZu0gW\r\nContent-Disposition: form-data; name=\"image_id\"\r\n\r\nnP0uKKO\r\n------WebKitFormBoundary7MA4YWxkTrZu0gW\r\nContent-Disposition: form-data; name=\"comment\"\r\n\r\nI'm a giraffe!\r\n------WebKitFormBoundary7MA4YWxkTrZu0gW--")
// Get body and http status code
body, status := DoStuff(parts[2], url, payload, token)
// If status is not OK
if status != 200 {
http.Error(w, "Could not post comment", status)
} else {
fmt.Fprintln(w, string(body))
}
DoStuff() does this
func DoStuff(method string, url string, body io.Reader, key string) ([]byte, int) {
// New request
req, err := http.NewRequest(method, url, body)
if err != nil {
fmt.Println(err)
}
// Add header with 'key' authorization
req.Header.Add("authorization", key)
res, err := http.DefaultClient.Do(req)
if err != nil {
fmt.Println(err)
}
defer res.Body.Close()
imgBody, err := ioutil.ReadAll(res.Body)
if err != nil {
fmt.Println(err)
}
return imgBody, res.StatusCode
}
I just get this error
{
data: {
error: "The parameter, image_id, is required.",
request: "/3/comment",
method: "POST"
},
success: false,
status: 400
}

Answer 1

The thing missing is the Content-Type header. You can modify your code like this:
In your handler HandleComment you can define the headers you want to pass to the request
case "POST":
// URL for POSTing comment
url := "https://api.imgur.com/3/comment"
// Authorization key
token := "Bearer " + os.Getenv("TOKEN")
// Payload
payload := strings.NewReader("------WebKitFormBoundary7MA4YWxkTrZu0gW\r\nContent-Disposition: form-data; name=\"image_id\"\r\n\r\nnP0uKKO\r\n------WebKitFormBoundary7MA4YWxkTrZu0gW\r\nContent-Disposition: form-data; name=\"comment\"\r\n\r\nI'm a giraffe!\r\n------WebKitFormBoundary7MA4YWxkTrZu0gW--")
// Headers
headers := map[string]string{
"Authorization": token,
"Content-Type": "multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW",
}
// Get body and http status code
body, status := DoStuff(parts[2], url, payload, headers)
// If status is not OK
if status != 200 {
http.Error(w, "Could not post comment", status)
} else {
fmt.Fprintln(w, string(body))
}
Update DoStuff to read and pass the headers
func DoStuff(method string, url string, body io.Reader, headers map[string]string) ([]byte, int) {
// New request
req, err := http.NewRequest(method, url, body)
if err != nil {
fmt.Println(err)
}
// Add headers
for k, v := range headers {
req.Header.Add(k, v)
}
res, err := http.DefaultClient.Do(req)
if err != nil {
fmt.Println(err)
}
defer res.Body.Close()
imgBody, err := ioutil.ReadAll(res.Body)
if err != nil {
fmt.Println(err)
}
return imgBody, res.StatusCode
}
I would suggest instead of using multipart/form-data; you might utilize the json content type. It is easier to manage and more readable
// Payload
payload := strings.NewReader("{\"image_id\": \"nP0uKKO\", \"comment\": \"I'm a giraffe!\"}")
// Headers
headers := map[string]string{
"Authorization": token,
"Content-Type": "application/json",
}