Right now my pages look something like this:
if($_GET['something'] == 'somevalue')
{
$output .= 'somecode';
// make a DB query, fetch a row
//...
$row = $stmt->Fetch(PDO::ASSOC);
if($row != null)
{
$output .= 'morecode';
if(somethingIsOK())
{
$output .= 'yet more page output';
}
else
{
$error = 'something is most definitely not OK.';
}
}
else
{
$error = 'the row does not exist.';
}
}
else
{
$error = 'something is not a valid value';
}
if($error == '') // no error
{
//display $output on page
}
else // an error
{
// display whatever error occurred on the page
}
The way I'm doing things works, but it's very cumbersome and tedious for what is probably obvious: suppose that I call a function somewhere in the middle of my code, or want to check the value of a variable, or verify a DB query returned a valid result, and if it fails I want to output an error? I would have to make another if/else block and move all of the code inside the new if block. This doesn't seem like a smart way of doing things.
I have been reading about try/catch and have been thinking of putting all of my code inside a try statement, then let the code run sequentially without any if/else blocks and if something fails just throw an exception. From what I've read, that would halt the execution and make it jump straight to the catch block (just as a failed if statement will go to the else block), where I could then output the error message. But is that an acceptable or standard practice?
What's the best way of handling errors, fatal or not, in a php application that builds and outputs an HTML page? I don't want to just die with a blank screen, as that would be very user un-friendly, but instead want to output a message in the body of the page, still allowing the header and footer to show.
Thanks for your advice!