Question

So I has a small problem as I outlined here.

I have made a new question because this is more general and will perhaps help others.

So essentially, I integrated the Facebook SDK Into Codeigniter as a library.

The SDK requires Json and Curl.

In the base_facebook.php file there is the following code:

    if (!function_exists('curl_init')) {
  throw new Exception('Facebook needs the CURL PHP extension.');
}
if (!function_exists('json_decode')) {
  throw new Exception('Facebook needs the JSON PHP extension.');
}

If these functions are not available I expect an error to be fired to tell me such. Then I can install the correct packages and continue.

What actually happened is that even when I had error reporting set to E_ALL a blank page was returned.

This made it impossible to debug and after lots of playing I worked out it was because CURL was not installed on my server.

My question is why does codeigniter show blank pages rather than library based exceptions?
Furthermore even if there is an exception in a library why does the rest of the page not continue executing.
Essentially CI is seemingly making the use of exceptions worthless..

COuld anyone advise?

THanks

Answer 1

My question is why does codeigniter show blank pages rather than library based exceptions?

Most likely because display_errors is set to “off”.

While this is recommended for a production environment (web site users are not supposed to see internal error messages – it might give them info about internals, that they are not supposed to have) – it’s not very helpful while developing, where you as the developer want to be informed about what went wrong.

So check if CI has a “debug” setting for this, or if it’s maybe already set to off in your PHP configuration.

(Maybe CI or your config are set up in a way that errors are logged to a file instead. Also recommended for production; while developing, you’d have to keep an eye on this file then.)

Furthermore even if there is an exception in a library why does the rest of the page not continue executing.

Because that’s how exceptions are supposed to work – if they are not being caught when they reach the “top level” of your app, they cause a fatal error, and scripts die when those occur.

Familiarize yourself with the concept of try { … } catch(…) { … } to handle exceptions that might occur in script flow.

(Actually, it’s kinda surprising you don’t know all this already, if you’re working with an advanced PHP framework …)