RESTful API Support

Here is a Tutorial that will show you how it is done. If you look in the system folder you will see a RETFUL folder.

Make sure you download the code at the end to view.

Tutorial How to Create RESTful API in CodeIgniter 4 (Complete Guide)

That tutorial is very poor.

He's not doing any validation. He's working with JSON and x-www-form-urlencoded. These are easy to parse. What if the user/client sends a multipart/form-data? If the form includes both text inputs and file inputs, one has to use multipart/form-data. The data can't be sent in JSON or x-www-form-urlencoded format. This needs manual parsing, and then, validation.

How does one deal with file uploads in REST? I see no mention of this in the page you linked.

I get an error here when I send text and file (multipart/form-data). Is multipart/form-data illegal? Am I not allowed to use it? How do I upload a file, then?

Currently, it seems to me that request (body) handling is incomplete, and data validation is tightly coupled to JSON/x-www-form-urlencoded, file upload is also tightly coupled to POST method (because of the use of is_uploaded_file() in $file->isValid()). I find these limitations siily.