Add detail to Codeigniter Logs - php

Question

All the errors I'm interested in debugging in Codeigniter's log files are reporting that they come from /system/core/Loader.php when they don't. For example, here's a line:
ERROR | 2014-09-22 22:35:43 | "Severity: Notice --> Undefined variable: my_variable \/system\/core\/Loader.php(829) : eval()'d code 84"
I know which file this is coming from, and it's a view. I'm aware of debug_backtrace and I'm thinking about making a string of it and concatenating it onto the end of the $msg variable in an overridden Log.php, but I first wanted to check two things with all you friends:
Is debug_backtrace the best way to do this? It returns a huge amount of data.
Is anyone aware of someone that's already done this? Seems like an obvious need for anyone using Codeigniter (...still ;)

Answer 1

Here's some code you could adapt to your needs (I recommend creating a My_Log and not editing the system file just in case CI does ever get an update). The reason I have this is complicated and not useful as-is any longer, but it might give you a start:
protected function log_query ($query, $type)
{
$backtrace = debug_backtrace ();
$backtrace = array_slice ( $backtrace, 2, -2 ); // first and last two elements are things that never change
$traced = array ();
foreach ( $backtrace as $bt )
{
$func = isset ( $bt['function'] ) ? $bt['function'].'()' : '';
$line = isset ( $bt['line'] ) ? $bt['line'] : '';
$file = isset ( $bt['file'] ) ? str_replace ( APP, '', $bt['file'] ) : '';
$object = isset ( $bt['object'] ) ? get_class ( $bt['object'] ) : '';
$args = array (); build_args ( $bt['args'], $args );
$args = implode ( '; ', $args );
if ( $object )
{
$obj_func = $object . '->' . $func;
} else {
$obj_func = $func;
}
$traced[] = "$file $obj_func $line $args";
unset($args);
}
$traced = implode ( "\n\t", $traced );
$date = MYSQL_DATE_TIME;
$uri = isset ( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : '' ;
$query= preg_replace ( "/[\n\t]/", ' ', $query );
log_message ('error', "{$query}\n\n\t{$date} ({$type})\n\t{$uri}\n\t{$traced}\n--------------------------\n");
}