发生错误时如何防止ob_start（）输出？

Question

Please, consider the following example:

template.php:

<?php

echo $vars['arr'];

echo " -------- ";

echo $vars['obj'];

?>

test.php:

<?php
$file = "template.php";
$vars = array( 'arr' => array(), 'obj' => new StdClass() );  

var_dump( json_encode($vars)  );  

function loadFile($file, $vars)
{
    try 
    {
        if (is_array($vars) && !empty($vars)) {
            extract($vars);
        }

        ob_start();
        include $file;
        return ob_get_clean();
    } 
    catch (Exception $e) 
    {
        return false;
    }
}

loadFile($file, $vars);

?>

This code will output:

string(19) "{"arr":[],"obj":{}}"
PHP Catchable fatal error:  Object of class stdClass could not be converted to string in template.php

The problem here is, in the template.php I am considering $vars to be an array() however 1 of the elements is an Object as you can see from the json output.

Adding a simple checking in the template to verify if the ekement is an array or not would solve the problem, however I would need to this to multiple elements, elements, so, not very good =) so, I trying to find a way to prevent the error in the moment of binding the template and $vars.

Thank you

Answer 1

simply turn error_reporting off while parsing:

$old_level = error_reporting(0); // no errors, preserve old error reporting level
ob_start();
include $file;
$content = ob_get_clean();
error_reporting($old_level); // reset error reporting level
return $content;

Note: This will only hide errors that aren't very critical.

In order to catch a Catchable Fatal Error, see this question: How can I catch a "catchable fatal error" on PHP type hinting?

You need to register an error handler using set_error_handler:

function handleError($errno, $errstr, $errfile, $errline) {
  // handle error

  // return true, so the normal php handler doesn't get called
  return true;
}
set_error_handler('handleError');

If you want to integrate you handler cleanly into other code which also sets error_handlers, you might consider restoring the error handler afterwards using restore_error_handler