Custom Exceptions - when to use?

[phant0m]

Hi

 

I was wondering how you use custom exceptions.

I find it difficult to balance between just using different error messages and using new Exception Classes, because I want to be able to react to different kinds of Exceptions and I am not too fond of using error codes.

 

I tend to create new Exception classes so I can just have multiple catch blocks.

How do you use Exceptions?

[Andy-H]

Whats wrong with multiple catch blocks?

 

try {
   //call classes/autoload or whatever you wish to do
   //program runs here

} catch (UserErrorException $e) {
   //Display error
} catch (FormHandlerException $e) {
   //Display error with form data
} catch (Exception $e) {
   //Redirect to error page...
}

 

I can't see a problem with that?

[phant0m]

I was just wondering what ways there are, to respond to different kinds of errors instead of having an Exception class for each error type.

[phant0m]

anyone?

[ChemicalBliss]

I would use Custom Exceptions to report specific errors such as database errors or general function failure like bad input etc.

 

You can also customize the Exception class to take separate arguments.

 

-cb-

[Mchl]

Here's a series of blog posts that cover this topic pretty well:

http://www.brandonsavage.net/exceptional-php-introduction-to-exceptions/

http://www.brandonsavage.net/exceptional-php-extending-the-base-exception-class/

http://www.brandonsavage.net/exceptional-php-nesting-exceptions-in-php/