Set error handling output to JSON about headless HOT 4 CLOSED

How is your middleware implemented in a way it doesnt interfere with other sites where headles might not be used thus text/html would be correct?

from headless.

Well, we use headless for the whole TYPO3 instance. But I see your point. Tricky. :D

from headless.

What is your recommend way to handle 404, 403 and other errors with headless?
So far only HTML is returned instead of a JSON error response object.

My idea was to evaluate the response-status codes inside the frontend to handle the errors, unfortunately this does not work for multiple reasons if CORS comes into play.

Because the Frontend-App and API are served under different domains, I set the CORS header in TypoScript:

config {
  additionalHeaders {
    50.header = Access-Control-Allow-Origin: http://my-javascript-frontend.net
    51.header = Access-Control-Allow-Credentials: true
  }
}

This works good for all successful requests (status 200). But for error responses, the CORS header are not set. This leads the browser to blocking the XHR request, so the frontend is not even able to validate the response status code.

Access to XMLHttpRequest at 'https://api.my-typo3-headless.net/login/private-page' from origin 'http://my-javascript-frontend.net' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

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Duplicate of #202, please reopen if you have any other issues.

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