Stopping (most) WSoD in PHP
Attempting to remove the white screen of death from PHP scripts.
Anyone who has done any development with PHP will be familiar with the infamous White Screen of Death; a blank browser window indicating that something horrible has gone wrong. A common cause, for me at least, is making a method call on a null object – easy to do in an object oriented architecture.
The exact reason as to why your script has gone splat will be reported in the log file, but from a UX standpoint, giving a blank screen to your customers is far from ideal. It is particularly problematic in complicated platforms like Elgg and Known, which use output buffering and have a plugin architecture.
Here’s a quick bit of code which can catch many (all?) of these fatal errors, and at least echo something. A variation of this is already in Known. Place the code somewhere towards the start of your script…
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register_shutdown_function(function () { $error = error_get_last(); if ($error["type"] == E_ERROR) { // If you use output buffering, chuck away any existing buffer ob_clean(); // Set an appropriate HTTP error code http_response_code(500); // Construct your error message $error_message = "Fatal Error: {$error['file']}:{$error['line']} - \"{$error['message']}\", on page {$_SERVER['SERVER_NAME']}{$_SERVER['REQUEST_URI']}"; // Display a friendly message to your customers, giving them an option to email you about it! echo "<h1>Sorry, FizzBuzz experienced a problem!</h1>"; echo "FizzBuzz experienced a problem with this page and couldn't continue. The technical details are as follows:</p>"; echo "$error_message"; echo "<p>If you like, you can <a href=\"mailto:bugs@example.com?subject=" . rawurlencode("Fatal error in FizzBuzz at {$_SERVER['SERVER_NAME']}{$_SERVER['REQUEST_URI']}") . "&body=" . rawurlencode($error_message) . "\">email us for more information</a></p>."; // You'll also want to write the error to your log error_log($error_message); exit; } }); |
Hope this is useful to you!
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This Article was mentioned on brid-gy.appspot.com
Including parser errors? I figure this is the “most” part of the title!
Yeah, some things still aren’t caught – so for example, if you redeclare a function. But, it does catch things like calling unrecognised methods or functions – which can be handy if you’re running plugins that require modules etc.
This Article was mentioned on marcus-povey.co.uk