Troubleshooting POST Requests in JavaScript with Fetch to PHP Backend скачать в хорошем качестве

Troubleshooting POST Requests in JavaScript with Fetch to PHP Backend

Discover how to resolve issues when your PHP backend reads a `POST` request as empty by correctly handling JSON data with Fetch in JavaScript. --- This video is based on the question https://stackoverflow.com/q/75123449/ asked by the user 'Daveh0' ( https://stackoverflow.com/u/4014834/ ) and on the answer https://stackoverflow.com/a/75123804/ provided by the user 'Wisdom Ighofose' ( https://stackoverflow.com/u/13455016/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions. Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Javascript: Issues with POST request via Fetch Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l... The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license. If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com. --- Troubleshooting POST Requests in JavaScript with Fetch to PHP Backend If you've ever tried to send data from your front end to a PHP backend using a POST request with the Fetch API, you might have encountered a frustrating situation: the backend returns an empty POST request. This issue is common and can stem from how the data is formatted and sent. In this guide, we will explore the problem of sending JSON data using Fetch in JavaScript, and how to effectively resolve it so your PHP backend can read and process the data correctly. Understanding the Problem In the example presented, the developer is trying to send an email address using a POST request. The HTML <form> contains a simple input field for the email and a submit button. However, when utilizing the Fetch API to submit the form, the backend script reads the $_POST array as empty, causing confusion and frustration. Here’s what the HTML for the form looks like: [[See Video to Reveal this Text or Code Snippet]] The JavaScript used to handle the form submission includes code to prevent the default behavior, construct a JSON payload, and send it to the PHP backend: [[See Video to Reveal this Text or Code Snippet]] When this code is executed, the PHP script attempts to read the POST data but finds it empty. The log shows: [[See Video to Reveal this Text or Code Snippet]] This indicates that while the request was sent as POST, the data was not parsed correctly by PHP. Solution to the Problem Once the issue is understood, the solution is straightforward. The PHP backend needs to read the raw JSON data sent in the request body instead of relying on the $_POST superglobal array, which is used for form-encoded data. Here’s the updated PHP code: [[See Video to Reveal this Text or Code Snippet]] Why This Works Raw Data Access: Using file_get_contents('php://input'), you can access the raw data sent in the request body. This is crucial for POST requests where JSON data is sent. JSON Format: By setting the Content-Type header to application/json, you notify the server that the incoming data is in JSON format, which is why reading it as raw input is necessary. Final Steps To see the parsed JSON data in PHP, you can decode it from JSON format like this: [[See Video to Reveal this Text or Code Snippet]] Summary When using Fetch to send JSON data to a PHP backend, ensure that you read the input correctly using php://input. This approach allows you to effectively handle your data without losing it to an empty POST array. By implementing these changes, you will be able to successfully submit data from JavaScript to your PHP backend and see the results as expected. By following the steps outlined above, you can overcome the common pitfalls associated with POST requests when using Fetch in JavaScript, and ensure that your data flows smoothly from front end to back end. Happy coding!