try catch statement in PHP where the file does not upload

Question

I understand what try-catch statements do, but from reading the documentation on php.net, I would not be able to implement one into my own code. I need a real example to help me understand.

How can I turn this example into a try-catch statement, if the upload was not successful?

$move = move_uploaded_file($_FILES['file']['tmp_name'], $_SERVER['DOCUMENT_ROOT'].'/uploads/'.$_FILES['file']['name']);

if (!$move) {
    die ('File didn\'t upload');
} else {            
    //opens the uploaded file for extraction
    echo 'Upload Complete!';
}

This may not be a good example to work with, but any help would be appreciated.

see also: http://stackoverflow.com/questions/1087365 – dreftymac Oct 11 '11 at 17:32 — dreftymac, Oct 11 '11 at 17:32

Tom Haigh · Answer 1 · 2009-05-31T23:22:45.593

52

You could do it like this.

try {
    //throw exception if can't move the file
    if (!move_uploaded_file( ... )) {
        throw new Exception('Could not move file');
    }

    //do some more things with the file which may also throw an exception
    //...

    //ok if got here
    echo "Upload Complete!";
} catch (Exception $e) {
    die ('File did not upload: ' . $e->getMessage());
}

It is a bit pointless for the above example, but you should get the idea. Note that you can throw the exception(s) from anywhere (e.g. within a function/method that you call from withing the try{}) and they will propagate upwards.

edited May 31 '09 at 23:22

answered May 31 '09 at 23:15

Tom Haigh

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Thanks for your reply and answer! I understand this wasn't a great example. When would it be suitable to use an Exception? thanks! – Ben McRae May 31 '09 at 23:33
I don't thin there are good or bad examples. Try/Catch statements are useful, when they are useful. The only thing you should matter, is php will throw E_ERROR or E_WARNING when a function is misused. – Boris Guéry Jun 01 '09 at 00:03

score 9 · Answer 2 · answered May 31 '09 at 23:18

Well, if you want to use exceptions, you could do something like:

function handleUpload() {


    $move = move_uploaded_file($_FILES['file']['tmp_name'], $_SERVER['DOCUMENT_ROOT']."/uploads/".$_FILES['file']['name']);

    if (!$move) {
       throw new Exception('File Didnt Upload');
    }

}

try {
   handleUpload();
   echo "File Uploaded Successfully";
} catch(Exception $ex) {
   die($ex->getMessage);
}

I know this may seem like bloat - but you can call the method from anywhere in the call stack, and catch the exception at any point.

Just a note, that exception handling is a lot more useful if you have a class hierarchy for your exceptions. It's generally useful to use catch with specific Exception sub-classes, and this way you can choose what problems are handled at what level of the code. — Luke H, May 25 '12 at 18:45

score 7 · Answer 3 · edited Jan 04 '14 at 18:13

7

try-catch statements are used to handle exceptions. I don't believe that the function move_uploaded_files can throw and exception, as such I think that you code is written is correct. After the call, you look at the return code. If it's false, you end processing, otherwise you are report success.

edited Jan 04 '14 at 18:13

BenMorel

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answered May 31 '09 at 23:19

Sean

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His example is correct but I think the point was that he's trying to learn about exceptions rather than trying to fix/improve the sample code. – Steve Claridge May 31 '09 at 23:25
Thanks Everyone for your quick responses! This seems to not be the best example to learn from. When would be a good/right time to use an Exception then? – Ben McRae May 31 '09 at 23:31

score 4 · Answer 4 · answered Sep 23 '09 at 07:06

4

According to a similar post in PHPbug, only OO code (Object-Oriented code) throws exceptions. That would mean that functions such as move_uploaded_file won't throw their own exceptions, but some other code will.

answered Sep 23 '09 at 07:06

This is important that "only OO code (Object-Oriented code) throws exceptions." if you want to use it in directly a php functions (out of any class) you won't get throw message... – mfkocak Dec 17 '22 at 08:15

try catch statement in PHP where the file does not upload

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