Classe JsonApiErrorObject
Implementação da especificação de objeto de erro da API JSON. Veja mais: http://jsonapi.org/format/#error-objects

Uso

// creating a new Error Object:
 $error = new JsonApiErrorObject();
 // set some known data about the error:
 $error->setTitle(new LangText('LBL_ERROR_LABEL_TITLE'));
 $error->setDetail(new LangText('LBL_ERROR_LABEL_DETAIL'));
 $error->setCode(ERROR_CODE);
 // etc.. see more in source and phpDoc
 // creating new Error Object with known data directly in constructor, all parameters are optional:
 $error = new JsonApiErrorObject(
     // title: a short, human-readable summary of the problem that SHOULD NOT change from occurrence to occurrence of the problem, except for purposes of localization.
     new LangText('LBL_ERROR_LABEL_TITLE'),
     // detail: a human-readable explanation specific to this occurrence of the problem. Like title, this field’s value can be localized.
     new LangText('LBL_ERROR_LABEL_DETAIL'),
     // id: a unique identifier for this particular occurrence of the problem.
     ERROR_ID,
     // code: an application-specific error code, expressed as a string value.
     ERROR_CODE,
     // status: the HTTP status code applicable to this problem, expressed as a string value.
     STATUS,
     // links: a links object
     ['about' => 'Descrioption about the problem'],
     // source: an object containing references to the source of the error
     ['pointer' => '/test/foo/bar', 'parameter' => 'wrong'],
     // meta: a meta object containing non-standard meta-information about the error.
     ['some' => 'meta info']
 );
 // retriving Error Object from an Exception:
 try {
   // …do stuff
 } catch (Exception $e) {
   $error->retrieveFromException($e)
 }
 // retrieving Error object from a ServerRequestInterface:
 $error->retrieveFromRequest($request);
 // converting to an array:
 $array = $error->export();
 // converting to a JSON string:
 $json = $error->exportJson();