// http://pastebin.com/kHpaHQvi originally
// http://www.gravityhelp.com/forums/topic/show-total-donations
// usage: [donations form=37] where 37 is the form ID
add_shortcode('donations', 'total_donations');
function total_donations($atts) {
        $form_id = $atts['form'];
        // function to pull all the entries for one form
        $donations = RGFormsModel::get_leads($form_id);
        // start the total at zero
        $total = 0;
        // initialize a counter for the number of donations made
        $i = 0;
        // loop through all the returned results
        foreach ($donations as $amount) {
                // add each donation amount to the total
                // change 3 here to the field ID which holds the donation amount
                $total += $amount[3];
                // increment the counter so we know how many donations there are as well
                $i++;
        }
        // change this to your locale, or, if your locale is already defined, you can remove this line
        setlocale(LC_MONETARY, 'en_GB');
        // do some formatting and return the html output from the shortcode
        $output = "We have raised " . money_format('%i', $total) . " from $i donors.";
        // just the string above will be returned.  You can style it here or where you are using the shortcode
        return $output;
}
// needed for the above to process the donation shortcode in sidebar widget
add_filter('widget_text', 'do_shortcode');