AngularJs validate chilean rut

</*
<form name="formTest" novalidate>
    <input id="rut" name="rut" type="text" 
    ng-model="rut" placeholder="Ej. 11.222.333-4" autocomplete="off" ng-pattern="regexRut" 
    ng-change="validateRut(formTest.rut)" onkeypress="return (event.charCode >= 48 && event.charCode <= 57)  || event.charCode == 45 || event.charCode == 75  || event.charCode == 107;">
</form>
*/

//in Controller
vm.regexRut ="^([0-9]+-[0-9Kk])$";
vm.validateRut=function(formElement){
    var dv = function (T) {
        var M = 0, S = 1; for (; T; T = Math.floor(T / 10))
            S = (S + T % 10 * (9 - M++ % 6)) % 11; return S ? S - 1 : 'k';
    }

    var rut = formElement.$viewValue;
    if (rut) {    
        var splittedRut=rut.split('-');
        if(splittedRut.length === 2){
            if (String(dv(splittedRut[0])).toUpperCase() != (splittedRut[1]).toUpperCase()){
                formElement.$setValidity("rut", false);
            } else {
                formElement.$setValidity("rut", true);
            }
        }else{
            formElement.$setValidity("rut", false);
        }

    }
}


/* CSS/SASS
input[type="text"]{
    &.ng-not-empty.ng-invalid{
        border:2px solid red;
    }
}
*/