I am in tears as I type this, sobbing into my keyboard
I have wasted over a week trying to understand what is wrong. I can no longer learn or develop. I am going to have to give up learning to code if I cannot fix this.
I understand what CORS is. If I had the ability to edit the API server, I would, but I do not. I must use a 3rd party API. I do not have the time to develop my own to work with. I am UNABLE to develop using anything but a local server. I need to stop CORS issues.
I have been trying to fix this problem for days. I am at a complete standstill with my learning. A week of tears and frustratiion has ben spent on this.
I CANNOT:
use https://cors-anywhere.herokuapp.com. This fails and CORS still screams:
Access to XMLHttpRequest at 'https://cors-anywhere.herokuapp.com/https://randomuser.me/api/?page=1&results=10' from origin 'http://localhost:3000' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: The value of the 'Access-Control-Allow-Origin' header in the response must not be the wildcard '*' when the request's credentials mode is 'include'. The credentials mode of requests initiated by the XMLHttpRequest is controlled by the withCredentials attribute.
Develop non-locally
Proxy. Package.json just ignores it. I have made multiple attempts to use proxying to avoid CORS. All attempts have ended in complete failure.
I legitimately do not know what to do. This is my code. Please help me, I am in tears and I cannot learn React anymore until this is fixed.
import axios from "axios";
let getFriends = () => {
const config = {
method: "GET",
url: "https://cors-anywhere.herokuapp.com/https://randomuser.me/api/?page=1&results=10",
crossdomain: true,
headers: {
"Content-Type": "application/json"
},
};
return axios(config);
};
export { getFriends };
The reason you are going crazy trying to find a solution is because there is nothing YOU can do about CORS. Changing any header as the other solution recommends won't work, the server will still flag any origins which it does not allow calls from!
This is a value controlled by the SERVER whose API you are calling. And, as the error says, the server you are calling does not accept connections from localhost:3000.
As long as you are making requests from a browser that is on localhost:3000 to this API, you'll be hit with CORS issues.
If you want to ensure that the API itself is not broken, use a different tool like Postman to call to the API. This is like a 'server to server' call, and as such does not require CORS checks.
EDIT: The following call to the random user API seems to work:
import React, { useEffect } from 'react';
function App() {
const fetchRandomUsers = async () => {
const response = await fetch("https://randomuser.me/api/?page=1&results=10")
const json = await response.json()
json.results.forEach((result) => {
console.log(result)
})
}
// On mount, fetch random users
useEffect(() => {
fetchRandomUsers()
}, [])
return (
<></>
);
}
export default App;
Related
I'm using Axios and React in my frontend app. When I'm trying to send POST request over HTTPS with Axios (xhr, fetch) and faced with the strange issue - my POST request turns into GET in Edge dev tools.
Here is my request:
const response = await axios.post(
config.local + "/api/login/credentials",
{
login,
password
}
);
Then I tried to dig dipper - created a simple HTTPS server and tried to send POST request from the client.
const https = require('https');
const fs = require('fs');
const options = {
key: fs.readFileSync('server.key'),
cert: fs.readFileSync('server.crt')
};
const PORT = 8188;
function handleRequest(req, res){
console.log(req.method);
}
const server = https.createServer(options, handleRequest);
server.listen(PORT, function(){
console.log("Server listening on: https://localhost:" + PORT);
});
And then, as I understand it, that request does not reach the server.
Here are some links:
Issue link 1
Issue link 2
Is there any error in console? You could use Fiddler to trace the network traffic and see the details. Also mentioned in the first link you provided, you could also try the two solutions in your GitHub link:
Solution 1:
My issue is caused by HTTPS; the backend is requiring HTTPS while I send an HTTP post from front side. Now I fixed by changing both to HTTPS.
Or Solution 2:
I solved it by passing the data in a different format using the "URLSearchParams " class.
I had the same problem with:
Microsoft Edge 44.18362.267.0
Microsoft EdgeHTML 18.18362
Windows 10
I think the problem is that Edge only supports certain data types in post requests. If you want to use the content-type 'application/x-www-form-urlencoded' then use URLSearchParams to make it work in Edge and other browsers like Firefox and Chrome. Passing a querystring seems not to work in Edge even if it does in other browsers.
Modifying the original post source code, the result would be:
import Axios from 'axios'
import Promise from 'es6-promise'
Promise.polyfill()
const URL= 'http://192.168.0.112/account/login/username'
// Use URLSearchParams instead:
const dataParams = new URLSearchParams()
dataParams.append('username', 'admin')
dataParams.append('password', 'admin')
Axios.post(URL, dataParams, {
// if you still have problems try more specific options like:
// withCredentials: true,
// crossdomain: true,
// ...
})
.then(res=>{
console.log(res)
}
)
.catch(error=>{
console.log(error)
}
)
Aside from that, the issue in your question is usually caused by CORS. If you use CORS and request an untrusted origin, then Microsoft Edge will only send the GET request and lead to the failure of other requests. You could also refer to this thread to understand why CORS requests fail in Microsoft Edge but work in other browsers. Microsoft Edge also uses Enhanced Protected Mode, the outcome is that: if the site is trusted, it will make two requests, OPTIONS and GET, but if it's not trusted, it only makes the GET request which causes it to fail.
In my case problem was caused by a self-sign certificate. As soon as I started using normal certificate everything began to work.
I know this should be basic but I will despair on this if no one helps me.
I want to get a Signin Token from AWS Federation. This is possible when you call the link:
https://signin.aws.amazon.com/federation?Action=getSigninToken&Session={encodedSession}
Now when I try to fetch it (based on the example codes on the AWS documentation) with this code
await fetch(
"https://signin.aws.amazon.com/federation?Action=getSigninToken&" +
qs.stringify({
Session: JSON.stringify({
sessionId: data["accessKey"],
sessionKey: data["secretKey"],
sessionToken: data["sessionToken"]
})
})
it will fail with a CORS error. Even in 'no-cors' mode (I know this is bad) the CORB is blocking everything. How can i fix this?
This all is within a React component!
Edit:
Here is the error
I'm trying to connect to buffer's API (https://buffer.com/developers/api/oauth) via react.js using fetch(), but I'm getting a 400 error response.
This is running on my localhost but the site's accessible from the Internet.
Here's my code:
const queryString = require('query-string');
const parsed = queryString.parse(window.location.search);
const buffer_data = {
client_id: BUFFER_CLIENT_ID,
client_secret: BUFFER_CLIENT_SECRET,
redirect_uri: BUFFER_CALLBACK_URL,
code: parsed.code,
grant_type: 'authorization_code',
};
fetch(BUFFER_ACCESS_TOKEN_URL, {
method: 'post',
body: JSON.stringify(buffer_data),
}).then( data => {
console.log('data response ' + data);
return data.json();
}).then( response => {
console.log(response);
});
And here's the response:
{"error":"invalid_request","error_description":"Invalid grant_type
parameter or parameter missing"}
And the console prints this:
Failed to load https://api.bufferapp.com/1/oauth2/token.json: No
'Access-Control-Allow-Origin' header is present on the requested
resource. Origin 'http://myserver.com' is therefore not allowed
access. The response had HTTP status code 400. If an opaque response
serves your needs, set the request's mode to 'no-cors' to fetch the
resource with CORS disabled.
I've tried lots of things, like not serializing the data, trying sending many different headers, using a CORS chrome plugin, etc
Before coding this in react, I've successfully connected using PHP, but to do that I had to add an SSL certificate on my server.
I'm also open to use any library but haven't found one to do this job. Or any other fetching method, like axios?
Many thanks!
I don't know which browser you are using, but you might want to add Allow-Control-Allow-Origin
for your chrome browser (if you are using chrome). This is some issue that seems to occur when you are using localhost with chrome.
Also, i highly recommend using axios for fetching API's, it comes with some easy error logs that can help you pinning down the issue pretty fast.
Greetings!
I'm very new to React, and to practice, I am trying to build an application that fetches information from the Yelp API, but I'm having trouble getting a response. Yelp Fusion v3 requires an 'access_token'(which I've successfully received as a response in Postman). So to make this request in my application, I am using Axios. When I am making this request inside of componentDidMount(), as a response I get
XMLHttpRequest cannot load https://api.yelp.com/v3/businesses/search?term=sushi&location=Boston. Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:8080' is therefore not allowed access. The response had HTTP status code 500.
Though it may seem that I am incorrectly specifying the access_token and parameters, when running the same code in a separate file(not part of the application), I get the JSON response that I am looking for in my app.
Here is my componentDidMount():
componentDidMount: function () {
axios.get('https://api.yelp.com/v3/businesses/search?term=Sushi&location=Boston',{
headers: {
Authorization: `Bearer ${token}`
}
})
.then(function(res){
console.log(res)
})
.catch(function(err){
console.log(err)
})
},
I've tried the Yelp node module as well, but I am having no luck. Please help!
This error is a Cross-Origin error.
Web browsers have a catch with AJAX requests: They need to be addressed to the same origin or be authorized by the third-party itself, otherwise they are blocked. Since you have no control over Yelp, I suggest you take a workaround.
Available workarounds
You use something like jsonp. This method basically consists in making the request in a <script> tag. The server will wrap the response inside a Javascript script and it will be loaded unto the page. (https://en.wikipedia.org/wiki/JSONP). The server MUST offer this format for that workaround to work.
You use a reverse proxy. You can set NodeJS to act as one. In this setup, you will make your yelp request to your origin who will redirect it to the yelp server. This works because your Node proxy does not have the same limitations as your browser. (ex: https://github.com/nodejitsu/node-http-proxy)
There may be other ways to get around this, but those are popular methods.
Hope this helps.
So I'm building a status board for our internal use as developers here in the office. It will show number of commits, hours tracked, etc.
I am following this model for authenticating. After a user logs in with harvest it redirects them back to the app with the code param as a query string, I'm then taking that query string and passing it to a state to then do a fetch to get the access token (so that I can later pull API data).
What happens, is the login is successful but when you are redirected back to the app the fetch throws a Bad Request (400) error. I have tested in Postman and can get the correct response so I'm not sure what the issue is...
Here is some of the JS from the Main component that sets the states if there is a code param:
harvestState() {
// grab URL params
let urlParams = queryString.parse(location.search);
console.log(urlParams);
console.log(urlParams.code);
// set the state based on the paramater passed back
urlParams.code ? (
this.setState({
harvestcode: urlParams.code
})
) : (
this.setState({
harvestcode: 'none'
})
);
}
componentWillMount(){
this.harvestState();
}
And here is the fetch function in my Harvest component:
getHarvest(){
const clientSecret = 'XXXXXXXXXX';
// Set Harvest Headers
const harvestHeaders = {
headers: {
'Content-Type': 'application/x-www-form-urlencoded',
},
method: 'POST',
mode: 'no-cors',
body: {
'code': this.props.code,
'client_id': this.props.clientid,
'client_secret': clientSecret,
'redirect_uri': 'http://dash.mycompany.me',
'grant_type': 'authorization_code'
}
};
fetch('https://mycompany.harvestapp.com/oauth2/token', harvestHeaders)
.then( response => response.json() )
.then( token => {
console.log(token);
} )
}
componentDidMount(){
if( this.props.code !== 'none' ){
this.getHarvest();
}
}
Is there something here that I am doing wrong? Why does it always return a bad request? Any help would be appreciated. Thank you!
At least one issue you have is that when you use mode: 'no-cors' you’re telling the browser to handle the response as an opaque response, which means that you’re telling the browser to not make any properties of the response object accessible from JavaScript.
So if you make a mode: 'no-cors' request, response => response.json() is going to fail.
The only purpose for no-cors in practice is in combination with Service Workers when you’re just caching resources (e.g., images) from responses, without need to get properties of the responses.
Anyway, given that the client Web app making the requests in your deployment is running from a different origin than the server the requests are sent to, browsers are going to block the requests unless the server responds with the necessary CORS headers—Access-Control-Allow-Origin, for a start. For an explanation, see the MDN article HTTP access control (CORS).
That is, browsers block cross-origin requests made from JavaScript unless the server the requests are sent to opts-in to allowing those, with the Access-Control-Allow-Origin, etc., response headers. The reason Postman doesn’t block such requests is that Postman is not an arbitrary Web app running at some specific origin on the Web but is instead a browser plugin that you’ve intentionally installed. So it’s not bound the cross-origin restrictions browser enforce for Web apps.