I have a generated React site I am hosting in an S3 bucket. One of my components attempts to fetch something when loaded: The url I am fetching is an AWS API Gateway. I have enabled CORS there, via the dropdown, with no changes to the default configuration. In my console, for both the remote site and locally …
Tag: cors
fetch() unexpected end of input
I am using fetch() to grab data from api server. My error looks like this: Can you please tell me what am I doing wrong. Answer Opaque Responses A response for a no-cors request to a cross-origin resource has a response type of ‘opaque’. If you log the response before trying to turn it to JSON, yo…
Text response is empty when using fetch
The following code: is outputting: If I use curl: I get a token in text form back (length != 0). And if I output the response header via: I get: Why am I getting no text via fetch? Answer Remove mode: ‘no-cors’. When you use no-cors mode, you’re explicitly specifying that you want an “opaque respo…
‘Access-Control-Allow-Origin’ issue when API call made from React (Isomorphic app)
I’m running into an issue with my isomorphic JavaScript app using React and Express. I am trying to make an HTTP request with axios.get when my component mounts I am getting a status 200 res from the API, but I am not getting any response data and getting an error in my console However, if I make the re…
CORS on golang server & javascript fetch frontend
I have a golang HTTP server with code like: I call this HTTP endpoint from a JS frontend, a react app deployed on port 3000, using code: The above code fails with the following logs. On the server side: On the browser, in the developer tools logs: Can someone help fix the authentication problem ? I am not sur…
Catching ‘Origin is not allowed by Access-Control-Allow-Origin’ error
So, i want to detect/catch Cross-Domain access blocked error. After some thought i found out that it src loading is async & thus the catch block wont work. Is there any way to detect the error so i can handle it efficiently? Answer As @TamasHegedus commented, the image can still be loaded with the CORS er…
Cannot access Wikidata API
I’m trying to use the Wikidata API, but all I’m getting is: Fetch API cannot load https://www.wikidata.org/w/api.php?action=wbsearchentities&search=Ingmar%20Bergman&language=en&limit=20&format=json&origin=http%3A%2F%2Fwww.dev.example.com%3A3000. Response to preflight request do…
XMLHttpRequest cannot load XXX No ‘Access-Control-Allow-Origin’ header
tl;dr; About the Same Origin Policy I have a Grunt process which initiates an instance of express.js server. This was working absolutely fine up until just now when it started serving a blank page with the following appearing in the error log in the developer’s console in Chrome (latest version): XMLHtt…
Solve Cross Origin Resource Sharing with Flask
For the following ajax post request for Flask (how can I use data posted from ajax in flask?): I get a Cross Origin Resource Sharing (CORS) error: I tried solving it in the two following ways, but none seems to work. Using Flask-CORS This is a Flask extension for handling CORS that should make cross-origin AJ…
Request header field Access-Control-Allow-Headers is not allowed by Access-Control-Allow-Headers
I’m trying to send files to my server with a post request, but when it sends it causes the error: Request header field Content-Type is not allowed by Access-Control-Allow-Headers. So I googled the error and added the headers: Then I get the error: Request header field Access-Control-Allow-Origin is not …