I have client - server express app. Im trying to send an XHR request from frontend to my controller, while passing json data. My frontend code looks like this:
function handle_login(){
var username_field = document.getElementById('input_username');
var pass = document.getElementById('input_password');
if(username_field.value!=null)console.log(username_field.value);
console.log(pass.value);
//window.location.href = "/loginAttempt/"+username.value+"-"+pass.value;
var xhr = new XMLHttpRequest();
var url = "/home_pogled";
xhr.open("GET", url, true);
xhr.setRequestHeader("Content-type", "application/json");
var data = {
username : username_field.value,
password : pass.value
}
var json = JSON.stringify(data);
xhr.send(json);
xhr.onload = function() {//ob uspesnem odgovoru
var responseText = xhr.responseText;
//console.log("Backend server response -" +responseText);
// uporabi odgovor
};
xhr.onerror = function() {
console.log('There was an error!');
};
}
I can send the request and i'm certain that data is written to the json object prior to sending it, but when i do consonle.log(req.body) in my controller upor receiving the request the body is empty "{}", where is should havec ontained the username and password values in a json objkect. What am i missing?
Client Side:
We can't send object in GET method, it should be query params like below snippet
let url = `/home_pogled?username=${username_field.value}&password=${pass.value}`;
xhr.open('GET', url);
Server side (express app):
In express js, we can get the query params in req.query
let username = req.query.username;
let password = req.query.password
Related
So, I have a JS script that sends a request to the server and that works fine. However, I want the frontend to recieve a response containing some information and read it on the frontend and execute a function.
uploadButton.addEventListener("click", () => {
var formData = new FormData();
var request = new XMLHttpRequest();
request.open("POST", "/Page/Upload");
request.send(formData);
if (request.response.result == "Success") {
console.log("Result is success")
window.location = request.response.url;
}
}
My controller looks like this.
[HttpPost("/page/upload")]
public IActionResult Upload()
{
*working parts pertaining to reading the request are omitted*
var redirectUrl = Request.Host + "/" + page.PageURL;
return Json(new { result = "Success", url = redirectUrl});
}
What I want is for my JS script to access the returned Json and its contents. How would I do this?
Try using the following code. It will subscribe the readystatechange event and run when API response has been received
uploadButton.addEventListener("click", () => {
var formData = new FormData();
var request = new XMLHttpRequest();
request.open("POST", "/Page/Upload");
request.send(formData);
request.addEventListener("readystatechange", function () {
if (this.readyState === 4) {
var responseData = JSON.parse(this.responseText);
if (responseData.result == "Success") {
console.log("Result is success")
window.location = responseData.url;
}
}
});
});
I am getting the raw data of the drafted from Gmail API "get" method and sending it using Gmail API "send" method.
'var url = 'https://www.googleapis.com/gmail/v1/users/me/messages/id?
format=raw&alt=json&access_token=' + token;
url = url.replace("id", emailId);
var x = new XMLHttpRequest();
x.open('GET', url , true);
x.send();
x.onload = function() {
var jsonRes = JSON.parse(x.response);
sendEmail(jsonRes.raw);
}
function sendEmail(raw) {
if (raw) {
var request = new XMLHttpRequest();
var url = 'https://www.googleapis.com/gmail/v1/users/me/messages/send?alt=json&access_token=' + token;
params = "raw=" + raw;
request.open('POST', url , true);
request.setRequestHeader("Authorization", "Bearer " + token);
request.setRequestHeader("Content-type", "application/json");
request.send(params);
request.onload = function() {
if (200 === request.status) {
alert("Email sent successfully");
}
}
}`
I am getting 401 status.
If I am sending this raw data from API page itself, then it is sent successfully. Therefore the raw data is correct.
I am missing something while sending the email. Please help!
A 401 error means "invalid credentials", most likely because your token has expired or isn't valid.
The Google API explorer and Google Javascript libraries take care of the token for you (generally), but if you're calling the service endpoints directly with XMLHttpRequest(), you'll have to manage the token yourself.
If you want to go that route, here are the details you have to implement: https://developers.google.com/identity/protocols/OAuth2
You can try things out in the "Oauth2 playground": https://developers.google.com/oauthplayground/
Thank you for all responses.
I sent the email using the following code-
function sendEmail(raw) {
if (raw) {
var request = new XMLHttpRequest();
var url = 'https://www.googleapis.com/gmail/v1/users/me/messages/send';
var params = JSON.stringify({'raw': raw});
request.open('POST', url , true);
request.setRequestHeader("Authorization", "Bearer " + token);
request.setRequestHeader("Content-type", "application/json");
request.send(params);
request.onload = function() {
if (200 === request.status) {
alert("Email sent successfully");
}
}
}
}
There were two mistakes I rectified-
1. The token was sent in URL as well as header. It should be sent only in header.
2. The param raw was sent as String but it should be sent as a JSON object.
I am trying to POST to a google maps service. If you click on the URL you will see the JSON response that I am expecting to get
var XMLHttpRequest = require("xmlhttprequest").XMLHttpRequest;
var xhr = new XMLHttpRequest()
var url = "https://maps.googleapis.com/maps/api/directions/json?origin=Exeter&destination=Deal®ion=uk&mode=driving"
xhr.open('POST', url, true)
xhr.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
xhr.onload = function() {
// do something to response
alert(this.responseText)
}
However, this code gets stops after xhr.onload = function(). So I never get the response back. Is there an error in my code?
You forgot to send the request.
xhr.send("The string of application/x-www-form-urlencoded data you are POSTING goes here");
var XMLHttpRequest = require("xmlhttprequest").XMLHttpRequest;
var xhr = new XMLHttpRequest()
var url = "https://maps.googleapis.com/maps/api/directions/json?origin=Exeter&destination=Deal®ion=uk&mode=driving"
xhr.open('POST', url, true)
xhr.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
xhr.onload = function() {
// do something to response
alert(this.responseText)
}
xhr.send("data to be send");
Try this.
I am having some trouble getting an access token from a site for a web application. The response to the following is
"{"error":"invalid_request","error_description":"The grant type was not specified in the request"}".
I have specified the grant type below but it seems I have not formatted the request correctly.
Any suggestions?
var getToken = new XMLHttpRequest();
getToken.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
document.getElementById("demo").innerHTML =
this.responseText;
}
};
getToken.open("POST", "https://api2.libcal.com/1.1/oauth/token", true);
getToken.send('grant_type=client_credentials','client_id=XXX', 'client_secret=XXXXXXXXXXXXXXXXXXXX');
As you are doing a Post Request to get an access token , the parameters should be send in the body (JSON) like below : (I tested ,it works fine )
// form data for the post request
var data = {
"grant_type":"client_credentials",
"client_id": "XXX",
"client_secret": "XXXXXXXXXXXXXXXXXXXX"
};
// construct an HTTP request
var getToken= new XMLHttpRequest();
getToken.open("POST", "https://api2.libcal.com/1.1/oauth/token", true);
getToken.setRequestHeader('Content-Type', 'application/json');
// send the collected data as JSON
getToken.send(JSON.stringify(data));
I am trying to send data to node via a XMLhttprequest. The data looks like this (/q/zmw:95632.1.99999.json). My connection to Node is correct, however, I was getting an empty object so I set the headers to Content-Type application/json and then stringified the data. However Node gives me a Unexpected token " error. I presume it is because of the string, however, if I don't stringify the data then it errors out because of the "/" in the data. How do i properly send the data using pure Javascript. I want to stay away from axios and jquery because I want to become more proficient in vanilla javascript. I will make the final call to the api in node by assembling the url prefix and suffix.
Here is my code:
function getCityForecast(e){
//User selects option data from an early JSONP request.
var id = document.getElementById('cities');
var getValue = id.options[id.selectedIndex].value;
//Assembles the suffix for http request that I will do in Node.
var suffix = getValue + ".json";
var string = JSON.stringify(suffix);
console.log(suffix);
var xhr = new XMLHttpRequest();
xhr.open("POST", "http://localhost:3000/", true);
xhr.setRequestHeader("Content-Type", "application/json;charset=UTF-8");
xhr.send(string);
}
Node.js code:
var express = require('express');
var app = express();
var bodyParser = require('body-parser');
var path = require('path');
var request = require('request');
var http = require('http');
// ****************** Middle Ware *******************
app.use(bodyParser.urlencoded({ extended: true }));
app.use(bodyParser.json());
app.use(express.static(__dirname + '/public'));
app.post('/', function(req, res){
console.log('working');
console.log(req.body);
});
app.listen(3000, function() { console.log('listening')});
I figured it out my mistake and this was my problem. I was trying to send a string instead of an object. So it wasn't proper JSON like this:
var string = JSON.stringify(suffix);
To remedy the situation I added:
var newObj = JSON.stringify({link : suffix});
This allowed my post to be successful because I was now sending an object hence the word Javascript Object Notation.
This is working for me, at the moment. The REST API I'm hitting requires a token. Yours might not, or it might be looking for some other custom header. Read the API's documentation. Note, you might need a polyfill/shim for cross browser-ness (promises). I'm doing GET, but this works for POST, too. You may need to pass an object. If you're passing credentials to get a token, don't forget window.btoa. Call it like:
httpReq('GET', device.address, path, device.token).then(function(data) {
//console.log(data);
updateInstrument(deviceId,path,data);
}, function(status) {
console.log(status);
});
function httpReq(method, host, path, token) {
if(method === "DELETE" || method === "GET"|| method === "POST" || method === "PUT" ){
var address = 'https://' + host + path;
return new Promise(function(resolve, reject) {
var xhr = new XMLHttpRequest();
xhr.open(method, address, true);
xhr.setRequestHeader("Accept", "application/json");
xhr.setRequestHeader ("X-auth-token", token);
//xhr.setRequestHeader ("Content-Type", "application/x-www-form-urlencoded");
xhr.onload = function() {
var status = xhr.status;
if (status == 200 || status == 201 || status == 202) {
resolve(xhr.response);
}
// this is where we catch 404s and alert what guage or resource failed to respond
else {
reject(status);
}
};
xhr.send();
});
} else {
console.log('invalid method');
}
};