An angular filter for validating Italian Codici Fiscali

cf-filter.js

(function() {
    var app = angular.module('cf', [])
        .filter('isCodiceFiscale', [codiceFiscale]);

	/**
	 * taken from https://gist.github.com/TheHiddenHaku/6951634
	 *  
	 * A function for evaluating if a string is a valid codice fiscale
	 *
	 * @param String codiceFiscale 
	 * 
	 * @returns true if is a valid codice fiscale, otherwise false
	 */
    function codiceFiscale(cfins) {
        var cf = cfins.toUpperCase();
        var cfReg = /^[A-Z]{6}\d{2}[A-Z]\d{2}[A-Z]\d{3}[A-Z]$/;
        if (!cfReg.test(cf)) {
            return false;
        }

        var set1 = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        var set2 = "ABCDEFGHIJABCDEFGHIJKLMNOPQRSTUVWXYZ";
        var setpari = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        var setdisp = "BAKPLCQDREVOSFTGUHMINJWZYX";
        var s = 0;
        for (i = 1; i <= 13; i += 2) {
            s += setpari.indexOf(set2.charAt(set1.indexOf(cf.charAt(i))));
        }
        for (i = 0; i <= 14; i += 2) {
            s += setdisp.indexOf(set2.charAt(set1.indexOf(cf.charAt(i))));
        }
        if (s % 26 != cf.charCodeAt(15) - 'A'.charCodeAt(0)) {
            return false;
        }
        return true;
    }

})();