Request works in POSTMAN but not by FETCH

Question

I am running into some trouble trying to figure out why my request is working on postman but not in the app (using fetchjs). The following is my request in the postman:

The Following is my code in node app using fetchjs:

fetchData() {
    let body = {}
    let method = "read";
    let id = "ctzeN5gn5fkQqj9uc";
    let vals = [method,{},id];
    let headers={
        "Accept": "application/json",
        "Content-Type": "application/json",
    };

    fetch('http://localhost:8000/v1/en/reviews', {
        method: 'POST',
        headers:headers,
        dataType:'json',
        body: JSON.stringify({vals:vals})
      }).then(res => res.json())
        .then(res => {
            console.log(res);
            if (res.error) throw (res.reason);
            this.setState({ data: res.data });
        })
        .catch(res => console.error(res))
}

The Following is my express server code:

let vals = this.req.body.vals;
if (!vals) throw new Error('Vals Missing');
let vals = JSON.parse(vals);
let method = vals[0];          //>>>error here (Unexpected token r)
let args = vals[1];
let id = vals[2];

I get the following response back :

SyntaxError: Unexpected token r"

the r is actually part of method (read).

Any idea on what i am doing wrong ? Any Suggestion is much appreciated.

Answer 1

In line 5: let vals = [method,vals,id]; there are two 'vals'?

Answer 2

fetchData() {
    let body = {}
    let method = "read";
    let id = "ctzeN5gn5fkQqj9uc";
    let vals = [method,{},id];
    let headers= {'Content-Type': 'application/x-www-form-urlencoded'};

    fetch('http://localhost:8000/v1/en/reviews', {
        method: 'POST',
        headers:headers,
        body: JSON.stringify({vals:vals})
      }).then(res => res.json())
        .then(res => {
            console.log(res);
            if (res.error) throw (res.reason);
            this.setState({ data: res.data });
        })
        .catch(res => console.error(res))
}

also

let vals = this.req.body.vals;
if (!vals) throw new Error('Vals Missing');
vals = JSON.parse(vals);
let method = vals[0];    

Answer 3

使用mode: 'cors'在您的选项上像mode: 'cors' ：

fetch("http://localhost:8000/v1/en/reviews", { mode: "cors", method: "POST", headers: headers, dataType: "json", body: JSON.stringify({vals: vals}) }) .then((res) => res.json()) .then((res) => { console.log(res); if (res.error) throw res.reason; this.setState({data: res.data}); }) .catch((res) => console.error(res));