Any way to exit outer function from within inner f

问题:

Within PHP, if I have one function that calls another function; is there any way to get the called function to exit out of the caller function without killing the entire script?

For instance, let's say I have some code something like:

<?php
function funcA() {
    funcB();
    echo 'Hello, we finished funcB';
}

function funcB() {
    echo 'This is funcB';
}
?>
<p>This is some text. After this text, I'm going to call funcA.</p>
<p><?php funcA(); ?></p>
<p>This is more text after funcA ran.</p>

Unfortunately, if I find something inside of funcB that makes me want to stop funcA from finishing, I seem to have to exit the entire PHP script. Is there any way around this?

I understand that I could write something into funcA() to check for a result from funcB(), but, in my case, I have no control over the contents of funcA(); I only have control over the contents of funcB().

To make this example a little more concrete; in this particular instance, I am working with WordPress. I am hooking into the get_template_part() function, and trying to stop WordPress from actually requiring/including the file through the locate_template() function that's called after my hook is executed.

Does anyone have any advice?

回答1:

Throw an exception in funcB that is not handled in funcA

回答2:

<?php
  function funcA() {
     try
     {
        funcB();
        echo 'Hello, we finished funcB';
     }
     catch (Exception $e) 
     {
        //Do something if funcB causes an error, or just swallow the exception
     }
  }

  function funcB() {
     echo 'This is funcB';
     //if you want to leave funcB and stop funcA doing anything else, just
     //do something like:
     throw new Exception('Bang!');
  }
?>

回答3:

The only way I see is using exceptions:

function funcA() {
    funcB();
    echo 'Hello, we finished funcB';
}

function funcB() {
   throw new Exception;
   echo 'This is funcB';
}
?>
<p>This is some text. After this text, I'm going to call funcA.</p>
<p><?php  try { funcA(); } catch (Exception $e) {} ?></p>
<p>This is more text after funcA ran.</p>

Ugly, but it works in PHP5.

回答4:

Maybe...

It's not an solution, but you could hook another function that gets called when exit() is requested "register_shutdown_function('shutdown');". And to somehow have this get things continue again or complete to your satifaction.

<?php
function shutdown()
{
    // This is our shutdown function, in 
    // here we can do any last operations
    // before the script is complete.

    echo 'Script executed with success', PHP_EOL;
}

register_shutdown_function('shutdown');
?>