Question

i have the following logic in my model:

if ( $switch_obj->connect() )  {
  if ( $data = $switch_obj->showIntAll() )  {
        $switch_obj->disconnect();  
        return $data;
  }
  else  {
     $switch_obj->disconnect();
     throw new Exception('Empty Data Set');
  }
}
else  {                                     
   throw new Exception('Connection');                                  
    }

This switch_obj that’s being called has logic in it’s constructor and destructor to increment / decrement counters respectively. (saved in a class called testclass).
So each time an object of type testclass is instantiated, a counter is increased. And then when destroyed, it’s decremented.
However, I’ve just discovered a scenario that I’m not handling.

Fatal error: Call to undefined method testclass::showIntAll() in
/var/www/myapp/application/models/test_model.php on line 215

It’s clear that I’m calling a method that doesn’t exist, which I will resolve. But my question is this: in creating this error, i can see that the counter has already been incremented … but not decremented because once this error is thrown, it never returns to the destructor method in my class.
How would I program for these types of scenarios? Obviously, in production, I won’t get getting errors because of missing methods in testclass… but in case I do get an unexpected error where the testclass constructor is called and then it bombs, I’m just wondering what the best way is to handle this.

Answer 1

You might achieve something with register_shutdown_function. Your constructor could register a clean-up function which would get called if an error would occur. You’d have to be careful not to call the clean-up code twice though (once from the destructor and once from this registered function.

Not a pretty solution, but it could work 🙂