Building A Generic Error Reporting Class In PHP - How Things Work
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Now, before proceeding further, I need to decide how this class is going to work. Here's how I plan to use it:

<?php
include_once("errorReporter.class.php");
$e = new errorReporter();

// 
errors in this section would be considered fatal
// open connection
$connection 
= mysql_connect("localhost", "user", "pass") or
$e->raiseError(102, "LOCALHOST");
mysql_select_db("store") 
or $e->raiseError(104, "STORE");

// formulate and execute query
$query = "SELECT 
id, label, desc, price,img_small FROM catalog LIMIT
0,3"; $result = mysql_query($query) 
or $e->raiseError(101, $query .
mysql_error());

// iterate through result set
// 
and print data for each item
// data consists of image, description, item ID 
and 
price
while(list($id, $label, $desc, $price, $img) = mysql_fetch_row($result))
{ 
?> <tr>
	<td>
	<img src="<? echo $img; ?>">
	</td>
	<td>
	<a 
href="details.php?id=<? echo $id; ?>"><? echo $label; ?></a>
	<br>
	<? 
echo $desc; ?>
	<br>
	<i>Only <? echo $price; ?></i>
	</td>
	</tr>
<?
}

// 
clean up
mysql_close($connection);

// check for missing form variables
// errors 
in this section would be considered non-fatal
if (!$sku) { $e->raiseError(1101, 
"SKU"); }
if (!$price) { $e->raiseError(1101, "PRICE"); }

// display non-fatal 
errors (if any)
if ($e->numErrors() > 0)
{
	$e->displayNonFatalErrors();
}

// 
if we get this far, it means the script encountered
// zero fatals and zero non-fatals
// 
in other words, the script was successfully executed
// display success page

include("success.tmpl");

?>

As you can see, I would like to wrap each function call in my script with a call to the errorReporter class. If a function call fails, an error will be generated via a unique error code and added to the error stack. If the error is evaluated as fatal, an appropriate error message will be immediately displayed to the user; if the error is evaluated as non-fatal, script processing will continue and the developer has the option to throw up an error screen at a later date containing a list of non-fatal errors.

Once the basic functionality of the class is clear, it's a good idea to spend some time listing the important methods, together with their purpose. Here's my initial cut:

raiseError($code, $data) - raise an error using a pre-defined error code and optional debug data;

numErrors() - check the number of errors currently held in the error stack;

displayFatalError($code, $data) - display the fatal error screen;

displayNonFatalErrors() - display the non-fatal error screen;

flushErrors() - reset the error stack.

These are the essential methods; there may be more, which I will add as development progresses.

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