zend framework2 - zf2 JSON-RPC server how to return custom error -

i'm looking proper way return custom error json-rpc exposed class.

json-rpc has special format reporting error conditions. errors need provide, minimally, error message , error code; optionally, can provide additional data, such backtrace.

error codes derived recommended xml-rpc epi project. zend\json\server appropriately assigns code based on error condition. application exceptions, code ‘-32000’ used.

i use divide method of sample code documentation explain:

<?php /**  * calculator - sample class expose via json-rpc  */ class calculator {     /**      * return sum of 2 variables      *      * @param  int $x      * @param  int $y      * @return int      */     public function add($x, $y)     {         return $x + $y;     }      /**      * return difference of 2 variables      *      * @param  int $x      * @param  int $y      * @return int      */     public function subtract($x, $y)     {         return $x - $y;     }      /**      * return product of 2 variables      *      * @param  int $x      * @param  int $y      * @return int      */     public function multiply($x, $y)     {         return $x * $y;     }      /**      * return division of 2 variables      *      * @param  int $x      * @param  int $y      * @return float      */     public function divide($x, $y)     {         if ($y == 0) {             // "y must not zero" in proper json-rpc error format             // e.g. {"error":{"code":-32600,"message":"invalid request","data":null},"id":null}          } else {             return $x / $y;         }     } }   $server = new zend\json\server\server(); $server->setclass('calculator');  if ('get' == $_server['request_method']) {     // indicate url endpoint, , json-rpc version used:     $server->settarget('/json-rpc.php')     ->setenvelope(zend\json\server\smd::env_jsonrpc_2);      // grab smd     $smd = $server->getservicemap();      // return smd client     header('content-type: application/json');     echo $smd;     return; }  $server->handle(); 

p.s. yes tried google search.

disclaimer: have no experience in using zend\json\server whatsoever :)

if talk error response, can correlate server::fault() method (also available on github). assume if fault() called , injected respones, return response error messages according referred recommended xml-rpc server standard.

the handler method proxies actual work _handle() (linked source) try/catch encapsuling dispatching (in case) calculator class.

the fault called based on exception message , exception code. such think it's throwing exception , setting right message/code there:

use zend\json\server\error;  class calculator {     public function divide($x, $y)      {         if (0 === $y) {             throw new invalidargumentexception(                 'denominator must non-zero numerical',                 error::error_invalid_params             );         }          // rest here     }      // rest here } 

ps. changed error code here, me, feels -32602 (invalid params) more appropriate -32600 (invalid request.