Here are a few question-based titles that fit the content of your article: * **Fetching Data from Remote APIs: Why Does \'no-cors\' Mode Cause \'Unexpected End of Input\'?** * **How to Hand

Error Handling in Fetch with 'no-cors' Mode

When attempting to resolve a fetch promise and setting the mode to 'no-cors,' developers may encounter an error when trying to return a response as JSON. This error, "Unexpected end of input," indicates a failure to parse the response due to its opaque nature.

Understanding Opaque Responses

As the error message suggests, an opaque response doesn't provide any information about the content it contains. This is a security measure implemented by CORS (Cross-Origin Resource Sharing) to prevent browsers from making certain requests that require permission from the server.

Fixing the Issue

To resolve this issue, two steps are necessary:

1. Remove 'no-cors' Mode: Using 'no-cors' mode instructs the browser to fail silently when encountering CORS errors. To access the response, this mode should be removed.
2. Enable CORS Permissions on the Server: The server that hosts the API endpoint must grant permission to the origin making the request. This can be done by setting the appropriate 'Access-Control-Allow-Origin' headers.

Alternative Approach

If obtaining CORS permissions is not feasible, consider using a proxy server that can intercept requests and handle CORS issues transparently. This solution may introduce additional latency but can be a viable workaround in certain situations.

Conclusion

By understanding the purpose of opaque responses and the implications of 'no-cors' mode, developers can troubleshoot errors related to fetching data from remote APIs. By removing 'no-cors' and ensuring proper CORS permissions on the server, they can retrieve and parse responses as expected.

The above is the detailed content of Here are a few question-based titles that fit the content of your article: * **Fetching Data from Remote APIs: Why Does \'no-cors\' Mode Cause \'Unexpected End of Input\'?** * **How to Hand. For more information, please follow other related articles on the PHP Chinese website!