PHP RFC: Add support for parsing request body in JSON format

• Version: 0.1
• Date: 2018-10-02
• Author: CHU Zhaowei jhdxr@php.net
• Status: Draft
• First Published at: https://wiki.php.net/rfc/parse_request_body_in_json

Currently PHP only parse request body when the Content-Type is application/x-www-form-urlencoded or multipart/form-data.[1] This RFC proposes to parse request body with Content-Type application/json or text/json.

It's very common for javascript library to send JSON payload now, however, PHP doesn't have built-in support for it. Userland developers have to deserialize it by themselves, which is inefficient and inconvenient. This RFC proposes to reuse the ability from ext/json to deserialize the payload and fill in $_POST.

For example,

curl -i -H "Content-Type: application/json" -X POST http://localhost:8000 -d '{"foo":"123","bar":456}'

will get

var_dump($_POST);
/*
array(2) {
  ["foo"]=>
  string(3) "123"
  ["bar"]=>
  int(456)
}
*/

Some edge cases:

1. illegal data: If the payload cannot be decoded, $_POST will be an empty array.
2. scalar type value: If the payload is a simple scalar type value, like numbers, string, TRUE or FALSE, $_POST will be an empty array.
3. large number value: Large number will be stored as string, which means JSON_BIGINT_AS_STRING is enabled. There won't be an option/setting for this because this is how $_POST deal with large numbers.

$_POST will be filled instead of an empty value when Content-Type is application/json or text/json.

Next PHP 7.x

New SAPI_POST_HANDLER_FUNC will be introduced to implement this RFC.

This RFC doesn't introduce any new settings.

Requires a 2/3 majority to pass.

Links to any external patches and tests go here.

If there is no patch, make it clear who will create a patch, or whether a volunteer to help with implementation is needed.

Make it clear if the patch is intended to be the final patch, or is just a prototype.

For changes affecting the core language, you should also provide a patch for the language specification.

After the project is implemented, this section should contain

1. the version(s) it was merged into
2. a link to the git commit(s)
3. a link to the PHP manual entry for the feature
4. a link to the language specification section (if any)

[1] https://secure.php.net/manual/en/reserved.variables.post.php