Question

I have a project object.
A user can assign a worker object for it.

99% of the case the project object has all the proper fields set.
In some cases, the project is missing a field.

In order for a worker to be assign to a project the project must have all the required fields setup.

To solve this, I throw exceptions like this: ( don’t try to find a pattern here, the real example is more complex )

if ($project->startDate == false ) {
  throw new Exception("Missing startDate attribute for project id: $id");
}


if ($project->finishDate == false ) {
  throw new Exception("Missing finishDate attribute for project id: $id");
}

if ($project->startDate > $project->finishDate ) {
  throw new Exception("Invalid start date for project id: $id");
}

The problem with this is that I need to display a custom message to the user each time. For example if the first error is thrown the user should see: ‘Please setup the project start date’ and so on.

How can I do this ?

Answer 1

Just define your own exception class and your whole code in a try .. catch:

class FormException extends Exception {
   private var $userMessage;
   public function __construct($message, $userMessage) {
     parent::__construct($message);
     $this->userMessage = $userMessage;
   }
   public function getUserMessage() {return $this->userMessage;}
}

try {
  // Whole code goes here, probably a function call
  throw new FormException("Missing startDate attribute for project id: $id",
                          'Please setup the project start date');
} catch (FormException $e) {
  echo $e->getUserMessage();
  error_log($e->getMessage());
}

By the way, if you want to include variable contents in a string, either use double quotes ("id: $id") or concatenate ('id: ' . $id).