如何将该函数转换为Angular指令

Question

How can I convert this function into an AngularJS directive? I want to make it validate user input in real time. But even when I'm trying to use it as regular function in controller I'm getting an error:

"Error: pesel.substring is not a function"

function decode(pesel) 
{
    var year=parseInt(pesel.substring(0,2),10);
    var month = parseInt(pesel.substring(2,4),10)-1;
    var day = parseInt(pesel.substring(4,6),10);

    if(month>80) {
        year = year + 1800;
        month = month - 80;
    }
    else if(month > 60) {
        year = year + 2200;
        month = month - 60;
    }
    else if (month > 40) {
        year = year + 2100;
        month = month - 40;
    }
    else if (month > 20) {
        year = year + 2000;
        month = month - 20;
    }
    else {
        year += 1900;
    }

    var birthday=new Date();
    birthday.setFullYear(year, month, day);

    var weights = [9,7,3,1,9,7,3,1,9,7];
    var sum = 0

    for(var i=0;i<weights.length;i++) {
        sum+=(parseInt(pesel.substring(i,i+1),10) * weights[i]);
    }

    sum=sum % 10;
    var valid=(sum===parseInt(pesel.substring(10,11),10));

    //sex
    if(parseInt(pesel.substring(9,10),10) % 2 === 1) { 
        var sex='m';
    } else {
        var sex='f';
    }

    return {valid:valid,sex:sex,date:birthday};
}

Answer 1

As Abdo stated above the value you are passing to your function, pesel , probably isn't a string.

The first line in your function should be:

pesel = (pesel || '').toString();

This line makes sure you don't stringify falsey variables and will make sure pesel is in fact a string.

Answer 2

If you want to validate some input, consider as a better option to create a parser/formatter pair or a validator for that purpose.

Use formatter/parsers for retrieving birthday and sex values, and a validator to check the value.

Best