ApiProblem

 use Crell  ApiProblem  ApiProblem ;

$ problem = new ApiProblem ( " You do not have enough credit. " , " http://*exam*p*le.com/probs/out-of-credit " );
// Defined properties in the API have their own setter methods.
$ problem
  -> setDetail ( " Your current balance is 30, but that costs 50. " )
  -> setInstance ( " http://exampl*e.**net/account/12345/msgs/abc " );
// But you can also support any arbitrary extended properties!
$ problem [ ' balance ' ] = 30 ;
$ problem [ ' accounts ' ] = [
  " http://exam*p*le.*net/account/12345 " ,
  " http://*exam**ple.net/account/67890 "
];

$ json_string = $ problem -> asJson ();

// Now send that JSON string as a response along with the appropriate HTTP error
// code and content type which is available via ApiProblem ::CONTENT_TYPE_JSON.
// Also check out asXml() and ApiProblem ::CONTENT_TYPE_XML for the angle-bracket fans in the room.

 $ response = new MyFrameworksJsonResponse ( $ problem );

// Or do it yourself
$ body = json_encode ( $ problem );

 use Crell  ApiProblem  HttpConverter ;

$ factory = getResponseFactoryFromSomewhere ();

// The second parameter says whether to pretty-print the output.
$ converter = new HttpConverter ( $ factory , true );

$ response = $ converter -> toJsonResponse ( $ problem );
// or
$ response = $ converter -> toXmlResponse ( $ problem );

 use Crell  ApiProblem  ApiProblem ;

$ problem = ApiProblem :: fromJson ( $ some_json_string );
$ title = $ problem -> getTitle ();
$ type = $ problem -> getType ();
// Great, now we know what went wrong, so we can figure out what to do about it.