Add filter "zero padding"

[goodseller]

Another filter I found useful is the zero padding. Would you mind to add it in the library also? Thanks.

String.prototype.repeat = function( num ) {
    return new Array( num + 1 ).join( this );
}

app.filter('zeroPadding', function () {
    return function(input, n) {
        if(input === undefined)
            input = "";
        if(input.length >= n)
            return input;
        var zeros = "0".repeat(n);
        return (zeros + input).slice(-1 * n);
    };
});

Here is a reference: https://gist.github.com/njouanin/3348ed708d527de8641c

[mallowigi]

@a8m We should do a "angular-filter-contrib" for all these requests.

[anonomis]

@mallowigi actually do it then? want help? :)