Turn php errors into exceptions; Codeigniter's implementation, but can be adapted for every other project.

error_handler_helper.php

<?php

# Error handler
function custom_error_handler($errno, $errstr, $errfile, $errline)
{
    if (AppSettings::$env == 'dev')
    {
        throw new ErrorException($errstr, 0, $errno, $errfile, $errline);
    }
    else
    {
        custom_exception_handler(new ErrorException($errstr, 0, $errno, $errfile, $errline));
    }
}


# Shutdown method to find out whether shutdown was because of any fatal error
function fatal_error_shutdown_handler()
{
  $last_error = error_get_last();
  if ($last_error['type'] === E_ERROR || $last_error['type'] === E_PARSE)
  {
    custom_exception_handler(new ErrorException($last_error['message'], 0, 0, $last_error['file'], $last_error['line']));
  }
}


# Exception handler
function custom_exception_handler($exception)
{
    $post = $_POST;
    unset($post['some confidential variable that shouldn\'t be logged']);
    $message = (string)$exception;
    get_instance()->db->query(
        'INSERT INTO system_errors (type, request, post_data, errors, website) VALUES (?, ?, ?, ?, ?)',
        array('php', print_r($_SERVER, TRUE), print_r($post, TRUE), $message, 'www')
    );

    if (AppSettings::$env == 'dev')
    {
        echo "<br />\n" . str_replace("\n", "<br />\n", $message) . "<br />\n";
    }
}


# Register handlers
set_error_handler('custom_error_handler', E_ALL);
set_exception_handler('custom_exception_handler');
register_shutdown_function('fatal_error_shutdown_handler');

?>

system_errors.sql

-- PostgreSQL --

CREATE TABLE "system_errors" (
    "id" serial NOT NULL,
    "type" text NOT NULL DEFAULT ''::text,
    "request" text NOT NULL DEFAULT ''::text,
    "post_data" text NOT NULL DEFAULT ''::text,
    "errors" text NOT NULL DEFAULT ''::text,
    "website" varchar(15) NOT NULL DEFAULT ''::character varying,
    "created" timestamp NOT NULL DEFAULT now()
)
WITH (OIDS=FALSE);