我的require_once路径出了什么问题？

Question

I've switched my files over from a local environment to my vps and now my facebook notification isn't working even thought I'm pretty sure I've updated all the paths correctly. I've tried writing the require path numerous ways. I'm doing a "$.post" from jquery to a php page where the facebook notification is sent and am getting this error:

<b>Fatal error</b>:  Class 'Facebook' not found in 

<b>/home/zjkkvcxc/public_html/accepted.php</b> on line <b>9</b><br />

//THIS IS MY PHP REQUIRE PATH. 

require_once('php-sdk/facebook.php') ;

//IN MY LOCAL ENVIRONMENT I WAS USING THIS PATH BECAUSE IT WAS THE ONLY ONE THAT WORKED. THIS DOESN'T WORK ON MY VPS THOUGH. 

require_once(dirname(__FILE__).'/php-sdk/facebook.php') ;

Answer 1

I have faced issues like this before, and the best way to handle this is to set your true filepath as a variable & prepend that to your includes/requires. Becuase the whole dirname(__FILE__) setup can act oddly in different environments especially those that use symbolic links. Explicitly stating where files are to be set is the best solution.

So let’s assume this is your codebase path; as per your example:

/home/zjkkvcxc/public_html/

Set that as a variable that all of your pages load in some way like this:

$BASE_PATH = '/home/zjkkvcxc/public_html/';

And now when you make calls to the file system for your app, do this:

require_once($BASE_PATH . 'php-sdk/facebook.php');

What is nice about a setup like this is that you can make your app portable between environments by just changing $BASE_PATH to match your local environment. Like this might be a path for a MAMP (Mac OS X LAMP) setup:

$BASE_PATH = '/Application/MAMP/htdocs/';

Regarding how odd __FILE__ can act in symlinked environments, read up here:

Since PHP 4.0.2, _ FILE _ always contains an absolute path with symlinks resolved whereas in older versions it contained relative path under some circumstances.