Parse req.body in POST request

Question

I am using fetch API to send two values to my POST request handler...

fetch('http://localhost:8080/validation', {
        method:'POST',
        headers: {
            'Accept': 'application/json',
            'Content-Type': 'application/json'
        },
        body: JSON.stringify({
            email:this.state.email,
            password:this.state.password
        })

I want to save both email and password as strings on the server side. Here is my attempt...

type credentials struct {
    Test string
}

func Validate(rw http.ResponseWriter, req *http.Request, _ httprouter.Params) {

    decoder := json.NewDecoder(req.Body)

    var creds credentials

    err := decoder.Decode(&creds)

    if err != nil {
        panic(err)
    }

    fmt.Println(creds.Test)
}

The problem is I do not know how exactly the format of the structure being sent to the POST. I am attempting to save req.Body as a string but this yields nothing.

When I print fmt.Println I get a blank space. What is the proper way of parsing it?

Answer 1

Try with

type credentials struct {
    Email string `json:"email"`
    Password string `json:"password"`
}

You are receiving a JSON with two values. Receiving struct should have a structure matching your request. Otherwise, there are no placeholders to decode the JSON into, as in your case - email and password do not have matching struct fields. Btw. if you send "Test" in your JSON, this would work, as you have a Test field in your struct!

Regarding field names. If fields in JSON do not start with a capital letter or even have different names, then you should use so called tags. More on tags: https://golang.org/pkg/encoding/json/#Marshal

In my example I used them to match struct field names to your json fields, i.e. to make email from json match Email field of the credentials struct.