Subversion-Projekte lars-tiefland.zeldi.de_alt

// https://jqueryvalidation.org/creditcard-method/
// based on https://en.wikipedia.org/wiki/Luhn_algorithm
$.validator.addMethod( "creditcard", function( value, element ) {
        if ( this.optional( element ) ) {
                return "dependency-mismatch";
        }

        // Accept only spaces, digits and dashes
        if ( /[^0-9 \-]+/.test( value ) ) {
                return false;
        }

        var nCheck = 0,
                nDigit = 0,
                bEven = false,
                n, cDigit;

        value = value.replace( /\D/g, "" );

        // Basing min and max length on
        // https://dev.ean.com/general-info/valid-card-types/
        if ( value.length < 13 || value.length > 19 ) {
                return false;
        }

        for ( n = value.length - 1; n >= 0; n-- ) {
                cDigit = value.charAt( n );
                nDigit = parseInt( cDigit, 10 );
                if ( bEven ) {
                        if ( ( nDigit *= 2 ) > 9 ) {
                                nDigit -= 9;
                        }
                }

                nCheck += nDigit;
                bEven = !bEven;
        }

        return ( nCheck % 10 ) === 0;
}, "Please enter a valid credit card number." );