REST request data can't be read in 'put' method

Question

I'm trying to develop a RESTful API with PHP without using frameworks. While processing the request, the client data cannot be read using this: parse_str(file_get_contents("php://input"), $put_vars);

Here's the full code:

public static function processRequest() {

    //get the verb
    $method = strtolower($_SERVER['REQUEST_METHOD']);

    $request = new Request();

    $data = array();
    $put_vars = array();

    switch ($method) {
        case 'get':
            $data = $_GET;
            break;
        case 'post':
            $data = $_POST;
            break;
        case 'put':
            parse_str(file_get_contents("php://input"), $put_vars);
            $data = $put_vars;
            echo $data;
            break;
    }

    $request->setMethod($method);
    $request->setRequestVars($data);

    if (isset($data['data'])) {
        $request->setData(json_decode($data));
        echo 'data exists';
    }

    return $request;
}

I'm using cURL to rest the API and when I type this command: curl -i -X PUT -d '{"name":"a","data":"data1"}' http://localhost/my-rest-api/api/ I only get this back:

Array""

Why isn't the proper data returned?

EDIT

I also tested another piece of code that is supposed to be an API and file_get_contents('php://input', true) still returns null. Could it be that there's something wrong with the web server?

Solution 1

The parse_str is used to parse a query string(in form arg1=xyz&arg2=abc) and not JSON. You need to use json_decode to parse JSON strings.

$data = json_decode(file_get_contents("php://input"), true);

Here is the code that works:

$method = strtolower($_SERVER['REQUEST_METHOD']);
$data = array();

switch ($method) {
    case 'get':
        $data = $_GET;
        break;
    case 'post':
        $data = $_POST;
        break;
    case 'put':
        $data = json_decode(file_get_contents("php://input"), true);
        break;
}

var_dump($data);

Curl command:

curl -i -X PUT -d '{"name":"a","data":"data1"}' http://my-server/my.php

Response:

array(2) {
  ["name"]=>
  string(1) "a"
  ["data"]=>
  string(5) "data1"
}

Solution 2

Could it be that there's something wrong with the web server?

Actually yes. After banging my head on this for a few hours, I found that the culprit for the missing data was this:

Note: Prior to PHP 5.6, a stream opened with php://input could only be read once

Another piece of code was accessing the php://input before my code, and on servers with php < 5.6, this caused the input to be lost.

Only on PUT requests that is.

Comments

[Shimon Rachlenko]

don't use echo $data for testing, use either var_dump($data) or print_r($data)

[Shimon Rachlenko]

I recreated your code on my server and was able to run it using your curl command and it produces required result.

[Igor]

@ShimoRachlenko I Just edited the code and still get the same results

[Shimon Rachlenko]

Can you confirm that file_get_contents("php://input") give you the data you send? And another thing - how do you output the result?

[Igor]

How can it be confirmed? So far the output is printed using 'echo', as shown above.

[Shimon Rachlenko]

Do echo file_get_contents("php://input"), and also do print_r($data) after you json_decode it.

[Igor]

I also noticed that if I send data using 'POST', $_POST is empty.

[Shimon Rachlenko]

@Igor answer updated. The main point is to use var_dump instead of echo for debug.

[Igor]

Can you add the cURL command and response also? I get 'null' using the same code

[Mike Brant]

@Igor If you are sending JSON data via POST, it will also not be parsed into $_POST. What you need to do is set you HTTP Content header for the request to be application/json, such that PHP will not try to parse the data as a query string, and then you need to json_decode the raw input data as suggested here. This applies to any cases where you are sending data via JSON.

[Igor]

@MikeBrant Can I set the Content Header in cURL while making requests? I hope that's what you meant.

[Igor]

@ShimonRachlenko Thanks for the edit, but I still get different response with your code. Here's what I get: <pre class='xdebug-var-dump' dir='ltr'><font color='#3465a4'>null</font></pre> Do you have any idea why?

[Igor]

@MikeBrant Did you also try this code to see if it's working?

[Mike Brant]

@Igor How would I do that? I have no access to your code or servers. It seems that you are doing some sort of var_dump via xdebug based on the returned content. Looks like you need to do some debugging.

[Igor]

@MikeBrant The code I use is the one from this answer. I created an index.php file with this code in it, placed it on a server, used cURL to test the PUT method and despite Shimon's claim, get_file_contents('php://input') returns null. I don't see what I'm doing wrong.

[Vijay Kumar]

This was very helpful. Thank you for sharing.