Reading JSON POST using PHP

Question

I looked around a lot before posting this question so my apologies if it is on another post and this is only my second quesiton on here so apologies if I don't format this question correctly.

I have a really simple web service that I have created that needs to take post values and return a JSON encoded array. That all worked fine until I was told I would need to post the form data with a content-type of application/json. Since then I cannot return any values from the web service and it is definitely something to do with how I am filtering their post values.

Basically in my local setup I have created a test page that does the following -

$curl = curl_init(); curl_setopt($curl, CURLOPT_CUSTOMREQUEST, "POST");                                                                      curl_setopt($curl, CURLOPT_POSTFIELDS, $data);                                                                   curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);                                                                       curl_setopt($curl, CURLOPT_HTTPHEADER, array(                                                                               'Content-Type: application/json',                                                                                     'Content-Length: ' . strlen($data))                                                                        ); curl_setopt($curl, CURLOPT_URL, 'http://webservice.local/');  // Set the url path we want to call $result = curl_exec($curl);  //see the results $json=json_decode($result,true); curl_close($curl); print_r($json); 

On the webservice I have this (I have stripped out some of the functions) -

<?php  header('Content-type: application/json');  /* connect to the db */ $link = mysql_connect('localhost','root','root') or die('Cannot connect to the DB'); mysql_select_db('webservice',$link) or die('Cannot select the DB');  if(isset($_POST['action']) && $_POST['action'] == 'login') {     $statusCode = array('statusCode'=>1, 'statusDescription'=>'Login Process - Fail');     $posts[] = array('status'=>$statusCode);     header('Content-type: application/json');     echo json_encode($posts);      /* disconnect from the db */ } @mysql_close($link);  ?> 

Basically I know that it is due to the $_POST values not being set but I can't find what I need to put instead of the $_POST. I tried json_decode($_POST), file_get_contents("php://input") and a number of other ways but I was shooting in the dark a bit.

Any help would be greatly appreciated.

Thanks, Steve

Thanks Michael for the help, that was a definite step forward I now have at least got a repsonse when I echo the post....even if it is null

updated CURL -

  $curl = curl_init();   curl_setopt($curl, CURLOPT_HTTPHEADER, array('Content-Type: application/json'));    curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");    curl_setopt($curl, CURLOPT_URL, 'http://webservice.local/');     curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);   curl_setopt($curl, CURLOPT_POSTFIELDS, json_encode($data)); 

updated php on the page that the data is posted to -

$inputJSON = file_get_contents('php://input'); $input= json_decode( $inputJSON, TRUE ); //convert JSON into array  print_r(json_encode($input)); 

As I say at least I see a response now wheras prior it was returning a blank page

Answer 1

You have empty $_POST. If your web-server wants see data in json-format you need to read the raw input and then parse it with JSON decode.

You need something like that:

$json = file_get_contents('php://input'); $obj = json_decode($json); 

Also you have wrong code for testing JSON-communication...

CURLOPT_POSTFIELDS tells curl to encode your parameters as application/x-www-form-urlencoded. You need JSON-string here.

UPDATE

Your php code for test page should be like that:

$data_string = json_encode($data);  $ch = curl_init('http://webservice.local/'); curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST"); curl_setopt($ch, CURLOPT_POSTFIELDS, $data_string); curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); curl_setopt($ch, CURLOPT_HTTPHEADER, array(         'Content-Type: application/json',         'Content-Length: ' . strlen($data_string)) );  $result = curl_exec($ch); $result = json_decode($result); var_dump($result); 

Also on your web-service page you should remove one of the lines header('Content-type: application/json');. It must be called only once.

Answer 2

Hello this is a snippet from an old project of mine that uses curl to get ip information from some free ip databases services which reply in json format. I think it might help you.

$ip_srv = array("http://freegeoip.net/json/$this->ip","http://smart-ip.net/geoip-json/$this->ip");  getUserLocation($ip_srv); 

Function:

function getUserLocation($services) {          $ctx = stream_context_create(array('http' => array('timeout' => 15))); // 15 seconds timeout          for ($i = 0; $i < count($services); $i++) {              // Configuring curl options             $options = array (                 CURLOPT_RETURNTRANSFER => true, // return web page                 //CURLOPT_HEADER => false, // don't return headers                 CURLOPT_HTTPHEADER => array('Content-type: application/json'),                 CURLOPT_FOLLOWLOCATION => true, // follow redirects                 CURLOPT_ENCODING => "", // handle compressed                 CURLOPT_USERAGENT => "test", // who am i                 CURLOPT_AUTOREFERER => true, // set referer on redirect                 CURLOPT_CONNECTTIMEOUT => 5, // timeout on connect                 CURLOPT_TIMEOUT => 5, // timeout on response                 CURLOPT_MAXREDIRS => 10 // stop after 10 redirects             );               // Initializing curl             $ch = curl_init($services[$i]);             curl_setopt_array ( $ch, $options );              $content = curl_exec ( $ch );             $err = curl_errno ( $ch );             $errmsg = curl_error ( $ch );             $header = curl_getinfo ( $ch );             $httpCode = curl_getinfo ( $ch, CURLINFO_HTTP_CODE );              curl_close ( $ch );              //echo 'service: ' . $services[$i] . '</br>';             //echo 'err: '.$err.'</br>';             //echo 'errmsg: '.$errmsg.'</br>';             //echo 'httpCode: '.$httpCode.'</br>';             //print_r($header);             //print_r(json_decode($content, true));              if ($err == 0 && $httpCode == 200 && $header['download_content_length'] > 0) {                  return json_decode($content, true);              }           }     }