Fetch POST method gives empty body on Express server - javascript

I make a POST request from my browser client:
const post = async (url, body) => {
try {
const response = await fetch(url, {
method: `POST`,
headers: {
'Content-Type': 'application/x-www-form-urlencoded',
},
body
});
return response.json();
} catch (error) {
console.log(error.stack);
}
}
const data = await post(`http://localhost:4050/analyze`, { text });
And I handle it on Express server with this setup:
app.use(express.urlencoded({ extended: true }));
This is my route:
router.post(`/`, errorHandler(async (req, res, next) => {
const { text } = req.body;
console.log(req.body)
const value = await analyze(text);
res.json({ rephrased });
}));
The console.log shows me this:
{ 'object Object': '' }
Why fetch method gives me Object instead of text property?
UPDATE:
When I do Stringify:
method: `POST`,
headers: {
'Content-Type': 'application/x-www-form-urlencoded',
},
body: JSON.stringify(body)
The body became like this and console.log shows:
{ '{"text":"asdfasdf"}': '' }

You are passing fetch a plain object for the body and it doesn't know what to do with it, so it calls .toString() and gives you nothing useful.
Pass it a URLSearchParams object instead. (Here I assume text is a string)
const body = new URLSearchParams();
body.append("text", text);
This will convert to a application/x-www-form-urlencoded string.
(You can also omit the headers as fetch can infer the correct Content-Type from the URLSearchParams object.)
Re edit: JSON.stringify will encode the data as JSON. JSON is not application/x-www-form-urlencoded.

Related

NextAuth fetching api endpoint - req.body undefined

i'm trying to use NextAuthJS for authentication in my NextJS app..
I'm using this following code from documentation
authorize: async(credentials, req)=>{
const res = await fetch("http://localhost:3000/api/userverify",{
method: 'POST',
credentials: "include",
body: JSON.stringify(credentials),
headers: {
'Accept': 'application/json',
'Content-Type': 'application/json'
},
})
const user = await res.json()
if(res.ok && user){
return user
}
return null
}
the problem is the actual fetching, in the userverify.js i have this code:
export default async function verify(res, req){
const credentials = req.body
console.log(credentials)
const user = await findUser(credentials.email)
if(user){
if(await argon2.verify(req.body.password, user.password)){
res.status(200).send(user)
return user
}
else{
res.status(401).send("Credentials Incorrect")
}
}
}
req.body in this file is undefined, im not using express only nextjs built in api routes..
What can i do?
I think it is the order of arguments. did you try logging req and res. First argument is request and second is response:
export default async function verify(req, res){
Docs

JS Promises POST request throws invalid json response body

I have written a POST client side JS method that when I run (the server side is up and running) I get the following error message:
error { FetchError: invalid json response body at http://localhost:3000/addMovie reason: Unexpected token < in JSON at position 0
at /home/workspace/node_modules/node-fetch/lib/index.js:272:32
at processTicksAndRejections (internal/process/task_queues.js:86:5)
message:
'invalid json response body at http://localhost:3000/addMovie reason: Unexpected token < in JSON at position 0',
type: 'invalid-json' }
The contents of the client file are below. This is part of my attempt to learn JS Promises. It would be really helpful if you could please point me towards the right direction. To run this file, I just do node getPost.js
require('es6-promise').polyfill();
require('isomorphic-fetch');
// TODO
const postData = async ( url = '', data = {})=>{
// console.log(data)
const response = await fetch(url, {
method: 'POST', // *GET, POST, PUT, DELETE, etc.
credentials: 'same-origin', // include, *same-origin, omit
headers: {
'Content-Type': 'application/json',
},
body: JSON.stringify(data), // body data type must match "Content-Type" header
});
try {
const newData = await response.json();
console.log(newData);
return newData
}catch(error) {
console.log("error", error);
// appropriately handle the error
}
}
postData('http://localhost:3000/addMovie', '{"movie": "the matrix", "score": "5"}')
This is my /addMovie route definition.
const data = []
app.post('/addMovie', addMovie )
function addMovie (req, res){
console.log(req.body)
// data.push(req.body)
res.send('POST received')
}

How to post file data to Gitlab project using JavaScript fetch [duplicate]

I'm trying to POST a JSON object using fetch.
From what I can understand, I need to attach a stringified object to the body of the request, e.g.:
fetch("/echo/json/",
{
headers: {
'Accept': 'application/json',
'Content-Type': 'application/json'
},
method: "POST",
body: JSON.stringify({a: 1, b: 2})
})
.then(function(res){ console.log(res) })
.catch(function(res){ console.log(res) })
When using jsfiddle's JSON echo I'd expect to see the object I've sent ({a: 1, b: 2}) back, but this does not happen - chrome devtools doesn't even show the JSON as part of the request, which means that it's not being sent.
With ES2017 async/await support, this is how to POST a JSON payload:
(async () => {
const rawResponse = await fetch('https://httpbin.org/post', {
method: 'POST',
headers: {
'Accept': 'application/json',
'Content-Type': 'application/json'
},
body: JSON.stringify({a: 1, b: 'Textual content'})
});
const content = await rawResponse.json();
console.log(content);
})();
Can't use ES2017? See #vp_art's answer using promises
The question however is asking for an issue caused by a long since fixed chrome bug.
Original answer follows.
chrome devtools doesn't even show the JSON as part of the request
This is the real issue here, and it's a bug with chrome devtools, fixed in Chrome 46.
That code works fine - it is POSTing the JSON correctly, it just cannot be seen.
I'd expect to see the object I've sent back
that's not working because that is not the correct format for JSfiddle's echo.
The correct code is:
var payload = {
a: 1,
b: 2
};
var data = new FormData();
data.append( "json", JSON.stringify( payload ) );
fetch("/echo/json/",
{
method: "POST",
body: data
})
.then(function(res){ return res.json(); })
.then(function(data){ alert( JSON.stringify( data ) ) })
For endpoints accepting JSON payloads, the original code is correct
I think your issue is jsfiddle can process form-urlencoded request only. But correct way to make json request is pass correct json as a body:
fetch('https://httpbin.org/post', {
method: 'POST',
headers: {
'Accept': 'application/json, text/plain, */*',
'Content-Type': 'application/json'
},
body: JSON.stringify({a: 7, str: 'Some string: &=&'})
}).then(res => res.json())
.then(res => console.log(res));
From search engines, I ended up on this topic for non-json posting data with fetch, so thought I would add this.
For non-json you don't have to use form data. You can simply set the Content-Type header to application/x-www-form-urlencoded and use a string:
fetch('url here', {
method: 'POST',
headers: {'Content-Type':'application/x-www-form-urlencoded'}, // this line is important, if this content-type is not set it wont work
body: 'foo=bar&blah=1'
});
An alternative way to build that body string, rather then typing it out as I did above, is to use libraries. For instance the stringify function from query-string or qs packages. So using this it would look like:
import queryString from 'query-string'; // import the queryString class
fetch('url here', {
method: 'POST',
headers: {'Content-Type':'application/x-www-form-urlencoded'}, // this line is important, if this content-type is not set it wont work
body: queryString.stringify({for:'bar', blah:1}) //use the stringify object of the queryString class
});
After spending some times, reverse engineering jsFiddle, trying to generate payload - there is an effect.
Please take eye (care) on line return response.json(); where response is not a response - it is promise.
var json = {
json: JSON.stringify({
a: 1,
b: 2
}),
delay: 3
};
fetch('/echo/json/', {
method: 'post',
headers: {
'Accept': 'application/json, text/plain, */*',
'Content-Type': 'application/json'
},
body: 'json=' + encodeURIComponent(JSON.stringify(json.json)) + '&delay=' + json.delay
})
.then(function (response) {
return response.json();
})
.then(function (result) {
alert(result);
})
.catch (function (error) {
console.log('Request failed', error);
});
jsFiddle: http://jsfiddle.net/egxt6cpz/46/ && Firefox > 39 && Chrome > 42
2021 answer: just in case you land here looking for how to make GET and POST Fetch api requests using async/await or promises as compared to axios.
I'm using jsonplaceholder fake API to demonstrate:
Fetch api GET request using async/await:
const asyncGetCall = async () => {
try {
const response = await fetch('https://jsonplaceholder.typicode.com/posts');
const data = await response.json();
// enter you logic when the fetch is successful
console.log(data);
} catch(error) {
// enter your logic for when there is an error (ex. error toast)
console.log(error)
}
}
asyncGetCall()
Fetch api POST request using async/await:
const asyncPostCall = async () => {
try {
const response = await fetch('https://jsonplaceholder.typicode.com/posts', {
method: 'POST',
headers: {
'Content-Type': 'application/json'
},
body: JSON.stringify({
// your expected POST request payload goes here
title: "My post title",
body: "My post content."
})
});
const data = await response.json();
// enter you logic when the fetch is successful
console.log(data);
} catch(error) {
// enter your logic for when there is an error (ex. error toast)
console.log(error)
}
}
asyncPostCall()
GET request using Promises:
fetch('https://jsonplaceholder.typicode.com/posts')
.then(res => res.json())
.then(data => {
// enter you logic when the fetch is successful
console.log(data)
})
.catch(error => {
// enter your logic for when there is an error (ex. error toast)
console.log(error)
})
POST request using Promises:
fetch('https://jsonplaceholder.typicode.com/posts', {
method: 'POST',
headers: {
'Content-Type': 'application/json',
},
body: JSON.stringify({
// your expected POST request payload goes here
title: "My post title",
body: "My post content."
})
})
.then(res => res.json())
.then(data => {
// enter you logic when the fetch is successful
console.log(data)
})
.catch(error => {
// enter your logic for when there is an error (ex. error toast)
console.log(error)
})
GET request using Axios:
const axiosGetCall = async () => {
try {
const { data } = await axios.get('https://jsonplaceholder.typicode.com/posts')
// enter you logic when the fetch is successful
console.log(`data: `, data)
} catch (error) {
// enter your logic for when there is an error (ex. error toast)
console.log(`error: `, error)
}
}
axiosGetCall()
POST request using Axios:
const axiosPostCall = async () => {
try {
const { data } = await axios.post('https://jsonplaceholder.typicode.com/posts', {
// your expected POST request payload goes here
title: "My post title",
body: "My post content."
})
// enter you logic when the fetch is successful
console.log(`data: `, data)
} catch (error) {
// enter your logic for when there is an error (ex. error toast)
console.log(`error: `, error)
}
}
axiosPostCall()
I have created a thin wrapper around fetch() with many improvements if you are using a purely json REST API:
// Small library to improve on fetch() usage
const api = function(method, url, data, headers = {}){
return fetch(url, {
method: method.toUpperCase(),
body: JSON.stringify(data), // send it as stringified json
credentials: api.credentials, // to keep the session on the request
headers: Object.assign({}, api.headers, headers) // extend the headers
}).then(res => res.ok ? res.json() : Promise.reject(res));
};
// Defaults that can be globally overwritten
api.credentials = 'include';
api.headers = {
'csrf-token': window.csrf || '', // only if globally set, otherwise ignored
'Accept': 'application/json', // receive json
'Content-Type': 'application/json' // send json
};
// Convenient methods
['get', 'post', 'put', 'delete'].forEach(method => {
api[method] = api.bind(null, method);
});
To use it you have the variable api and 4 methods:
api.get('/todo').then(all => { /* ... */ });
And within an async function:
const all = await api.get('/todo');
// ...
Example with jQuery:
$('.like').on('click', async e => {
const id = 123; // Get it however it is better suited
await api.put(`/like/${id}`, { like: true });
// Whatever:
$(e.target).addClass('active dislike').removeClass('like');
});
Had the same issue - no body was sent from a client to a server.
Adding Content-Type header solved it for me:
var headers = new Headers();
headers.append('Accept', 'application/json'); // This one is enough for GET requests
headers.append('Content-Type', 'application/json'); // This one sends body
return fetch('/some/endpoint', {
method: 'POST',
mode: 'same-origin',
credentials: 'include',
redirect: 'follow',
headers: headers,
body: JSON.stringify({
name: 'John',
surname: 'Doe'
}),
}).then(resp => {
...
}).catch(err => {
...
})
This is related to Content-Type. As you might have noticed from other discussions and answers to this question some people were able to solve it by setting Content-Type: 'application/json'. Unfortunately in my case it didn't work, my POST request was still empty on the server side.
However, if you try with jQuery's $.post() and it's working, the reason is probably because of jQuery using Content-Type: 'x-www-form-urlencoded' instead of application/json.
data = Object.keys(data).map(key => encodeURIComponent(key) + '=' + encodeURIComponent(data[key])).join('&')
fetch('/api/', {
method: 'post',
credentials: "include",
body: data,
headers: {'Content-Type': 'application/x-www-form-urlencoded'}
})
The top answer doesn't work for PHP7, because it has wrong encoding, but I could figure the right encoding out with the other answers. This code also sends authentication cookies, which you probably want when dealing with e.g. PHP forums:
julia = function(juliacode) {
fetch('julia.php', {
method: "POST",
credentials: "include", // send cookies
headers: {
'Accept': 'application/json, text/plain, */*',
//'Content-Type': 'application/json'
"Content-Type": "application/x-www-form-urlencoded; charset=UTF-8" // otherwise $_POST is empty
},
body: "juliacode=" + encodeURIComponent(juliacode)
})
.then(function(response) {
return response.json(); // .text();
})
.then(function(myJson) {
console.log(myJson);
});
}
It might be useful to somebody:
I was having the issue that formdata was not being sent for my request
In my case it was a combination of following headers that were also causing the issue and the wrong Content-Type.
So I was sending these two headers with the request and it wasn't sending the formdata when I removed the headers that worked.
"X-Prototype-Version" : "1.6.1",
"X-Requested-With" : "XMLHttpRequest"
Also as other answers suggest that the Content-Type header needs to be correct.
For my request the correct Content-Type header was:
"Content-Type": "application/x-www-form-urlencoded; charset=UTF-8"
So bottom line if your formdata is not being attached to the Request then it could potentially be your headers. Try bringing your headers to a minimum and then try adding them one by one to see if your problem is resolved.
If your JSON payload contains arrays and nested objects, I would use URLSearchParams and jQuery's param() method.
fetch('/somewhere', {
method: 'POST',
body: new URLSearchParams($.param(payload))
})
To your server, this will look like a standard HTML <form> being POSTed.
You could do it even better with await/async.
The parameters of http request:
const _url = 'https://jsonplaceholder.typicode.com/posts';
let _body = JSON.stringify({
title: 'foo',
body: 'bar',
userId: 1,
});
const _headers = {
'Content-type': 'application/json; charset=UTF-8',
};
const _options = { method: 'POST', headers: _headers, body: _body };
With clean async/await syntax:
const response = await fetch(_url, _options);
if (response.status >= 200 && response.status <= 204) {
let data = await response.json();
console.log(data);
} else {
console.log(`something wrong, the server code: ${response.status}`);
}
With old fashion fetch().then().then():
fetch(_url, _options)
.then((res) => res.json())
.then((json) => console.log(json));
**//POST a request**
const createTodo = async (todo) => {
let options = {
method: "POST",
headers: {
"Content-Type":"application/json",
},
body: JSON.stringify(todo)
}
let p = await fetch("https://jsonplaceholder.typicode.com/posts", options);
let response = await p.json();
return response;
}
**//GET request**
const getTodo = async (id) => {
let response = await fetch('https://jsonplaceholder.typicode.com/posts/' + id);
let r = await response.json();
return r;
}
const mainFunc = async () => {
let todo = {
title: "milan7",
body: "dai7",
userID: 101
}
let todor = await createTodo(todo);
console.log(todor);
console.log(await getTodo(5));
}
mainFunc()
I think that, we don't need parse the JSON object into a string, if the remote server accepts json into they request, just run:
const request = await fetch ('/echo/json', {
headers: {
'Content-type': 'application/json'
},
method: 'POST',
body: { a: 1, b: 2 }
});
Such as the curl request
curl -v -X POST -H 'Content-Type: application/json' -d '#data.json' '/echo/json'
In case to the remote serve not accept a json file as the body, just send a dataForm:
const data = new FormData ();
data.append ('a', 1);
data.append ('b', 2);
const request = await fetch ('/echo/form', {
headers: {
'Content-type': 'application/x-www-form-urlencoded'
},
method: 'POST',
body: data
});
Such as the curl request
curl -v -X POST -H 'Content-type: application/x-www-form-urlencoded' -d '#data.txt' '/echo/form'
You only need to check if response is ok coz the call not returning anything.
var json = {
json: JSON.stringify({
a: 1,
b: 2
}),
delay: 3
};
fetch('/echo/json/', {
method: 'post',
headers: {
'Accept': 'application/json, text/plain, */*',
'Content-Type': 'application/json'
},
body: 'json=' + encodeURIComponent(JSON.stringify(json.json)) + '&delay=' + json.delay
})
.then((response) => {if(response.ok){alert("the call works ok")}})
.catch (function (error) {
console.log('Request failed', error);
});
// extend FormData for direct use of js objects
Object.defineProperties(FormData.prototype, {
load: {
value: function (d) {
for (var v in d) {
this.append(v, typeof d[v] === 'string' ? d[v] : JSON.stringify(d[v]));
}
}
}
})
var F = new FormData;
F.load({A:1,B:2});
fetch('url_target?C=3&D=blabla', {
method: "POST",
body: F
}).then( response_handler )
you can use fill-fetch, which is an extension of fetch. Simply, you can post data as below:
import { fill } from 'fill-fetch';
const fetcher = fill();
fetcher.config.timeout = 3000;
fetcher.config.maxConcurrence = 10;
fetcher.config.baseURL = 'http://www.github.com';
const res = await fetcher.post('/', { a: 1 }, {
headers: {
'bearer': '1234'
}
});

Retrieve then POST a photo to a Foursquare Checkin with Axios

I'm trying to retrieve, then POST a JPEG image to Foursquare's https://api.foursquare.com/v2/photos/add endpoint using Axios in Node. I've tried a few methods with Axios (and Postman) but always receive the same error response of Missing file upload:
{
"meta": {
"code": 400,
"errorType": "other",
"errorDetail": "Missing file upload",
"requestId": "NNNNNNNNNNNNNNNNNNNNN" // not the true requestId
},
"notifications": [
{
"type": "notificationTray",
"item": {
"unreadCount": 0
}
}
],
"response": {}
}
The image is created using the Google Static Map API and retrieved with an Axios GET request:
const image = await axios.get(imageURL, {
responseType: "arraybuffer"
});
which is wrapped in an async function and successfully returns a buffer. The data is read into a Buffer and converted to a string:
const imageData = new Buffer(image, "binary").toString();
Here's an example imageData string. I've also tried converting the string to base64.
This string is then POSTed to the Foursquare endpoint:
const postPhoto = await axios.post(
"https://developer.foursquare.com/docs/api/photos/add?
checkinId=1234&
oauth_token=[TOKEN]&
v=YYYYMMDD",
imageData,
{
headers: { "Content-Type": "image/jpeg" }
}
);
where the checkinId, oauth_token and v params are all valid.
I've tried different Content-Type values, base64 encoding the imageData and several other solutions found in forums and here on SO (most are several years old), but nothing works. The response errorDetail always says Missing file upload.
The issue could be in how the POST request is structured, but I could also be requesting/handling the image data incorrectly. A 2nd (or 3rd, or 4th) set of eyes to check I'm putting this together would be super helpful.
Whew, I have finally solved this.
I was eventually able to get it working thru Postman which provided some hints. Here's the Postman code snippet using request:
var fs = require("fs");
var request = require("request");
var options = { method: 'POST',
url: 'https://api.foursquare.com/v2/photos/add',
qs:
{ checkinId: [MY CHECKING ID],
public: '1',
oauth_token: [MY OAUTH TOKEN],
v: [MY VERSION] },
headers:
{ 'postman-token': '8ce14473-b457-7f1a-eae2-ba384e99b983',
'cache-control': 'no-cache',
'content-type': 'multipart/form-data; boundary=---- WebKitFormBoundary7MA4YWxkTrZu0gW' },
formData:
{ file:
{ value: 'fs.createReadStream("testimage.jpg")',
options: {
filename: 'testimage.jpg',
contentType: null
}
}
}
};
request(options, function (error, response, body) {
if (error) throw new Error(error);
console.log(body);
});
The key part of this was fs.createReadStream(). The part I was missing before was to pass the image as a stream to the request.
Using this I was able to figure out the Axios request:
const axios = require("axios");
const querystring = require("qs");
const FormData = require("form-data");
const getImageStream = async function(url) {
return await axios
.get(url, {
responseType: "stream"
})
.then(response => response.data);
};
let form = new FormData();
form.append("file", getImageStream([IMAGE URL]));
const requestURL = "https://api.foursquare.com/v2/photos/add";
const requestParams = {
checkinId: [MY CHECKIN ID],
public: 1,
oauth_token: [MY OAUTH TOKEN],
v: [MY VERSION]
};
const requestConfig = {
headers: form.getHeaders()
};
try {
const postPhoto = await axios.post(
requestURL + "?" + querystring.stringify(requestParams),
form,
requestConfig
);
return postPhoto;
} catch (e) {
console.error(e.response);
}
And voila, the request succeeds and the image is posted to the Foursquare checkin.

can't do POST to api, error 400 using fetch

fetch('/auth/signup', {
method: 'POST',
body: this.state.user,
headers: {
'Content-Type': 'application/json'
},
})
.then(function(response) {
return response.json();
})
.then(data => {
console.log(data);
})
this.state.user is basically an object like {user: {name:"someone"} and my server side code simply do this
router.post('/signup', (req, res, next) => {
console.log(req.body) // empty object
}
I think something is wrong with fetch, didn't see any data been pass in the network tab.
Pass this.state.user to JSON.stringify() before setting at body or use FormData to POST key, value pairs. body does not expect javascript object.
body: JSON.stringify(this.state.user)
let fd = new FormData();
let {user} = this.state.user;
for (let prop in user) {
fd.append(prop, JSON.stringify(user[prop]));
}
body: fd

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