CODEWITHSUNDEEP
go
user_78361084
user_78361084

Reputation: 3928

How do I redirect a GET request to a POST request with some data?

When a user hits a certain url with a GET request I'd like to redirect them to a POST request at another location. 

package main


import (
    "bytes"
    "fmt"
    "io/ioutil"
    "log"
    "net/http"
    "net/url"
)

func old(w http.ResponseWriter, r *http.Request) {
    newURL := "/new"
    var bdy = []byte(`title=Buy cheese and bread for breakfast.`)

    r.Method = "POST"
    r.URL, _ = url.Parse(newURL)
    r.RequestURI = newURL
    r.Body = ioutil.NopCloser(bytes.NewReader(bdy))
    r.Header.Set("Content-Type", "application/x-www-form-urlencoded")
    http.Redirect(w, r, newURL, 302)
}

func new(w http.ResponseWriter, r *http.Request) {
    r.ParseForm()
    fmt.Printf("Method:%v\n", r.Method)
    fmt.Printf("Title:%v\n", r.Form.Get("title"))
}

func main() {
    http.HandleFunc("/", old)
    http.HandleFunc("/new", new)
    port := 8000
    fmt.Printf("listening on %v\n", port)
    if err := http.ListenAndServe(fmt.Sprintf(":%v", port), nil); err != nil {
        log.Fatal("ListenAndServe: ", err)
    }
}

When I hit "/" I end up getting redirected to "/new" but with a GET request and no form data:

Method:GET
Title:

If I curl "/new" directly I get :

curl -XPOST localhost:8000/new -d "title=Buy cheese and bread for breakfast."

Method:POST
Title:Buy cheese and bread for breakfast.

Upvotes: 1

Views: 5425

Answers (3)

Eugene Lisitsky
Eugene Lisitsky

Reputation: 12875

I've never heard about changing verb from GET to POST. I guess it's impossible because POST supposes body of body (however may be empty) and GET doesn't. So in general case browser would not be able to take the body from nothing. Otherwise is possible: you may send 302 redirect after post to make browser perform get. Also verb can be kept with 307 reply code.

Try to rethink browser-server interaction. May be you can redirect POST to another location to solve a task?

Upvotes: 0

Steffen Ullrich
Steffen Ullrich

Reputation: 123521

A HTTP redirect (i.e. reply with status code 301, 302, 307,308 and Location header) can only redirect the existing request to another location and not change the payload of the request. It can add some cookies in the response header though.

In order to automatically change a GET request into a POST request with a specific payload you might try to send the client a HTML page with a <form method=POST... and the payload with hidden input fields, i.e. <input name=... value=... type=hidden> and then add some JavaScript to the page which automatically submits the form. But this kind of hack will only work in browsers and only if JavaScript is enabled and will not work with all kind of payloads either.

To keep compatibility with a broader range of clients it is probably better to design it differently, i.e. keep the GET request in the redirect but give the necessary payload as a parameter to the new target, i.e. http://new.target/foo?payload=..... But the details depend on what the target of the request can deal with.

Upvotes: 4

poy
poy

Reputation: 10527

Unfortunately I don't believe a redirect can change the verb (e.g., GET, POST) or add data to the request. It can only change the URL.

See Redirect () for more information.

Upvotes: 4

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