AngularJS pipe filter for handling decimals up to a max

angular-decimalmax.js

var module = angular.module('app', [])
//Just add this after you declare your main module
module.filter('decimalmax', ['$filter', function ($filter) {
  return function(num, params) {
    if (num == null) return 0;
    var v = (num + "").split(".");
    var pres = 0
    if (v.length > 1){
      var p = v[1].length;
      if (p <= params){
        //return p;
        pres = p;
      }
      else{
        //return 3;
        pres = params;
      }
    }
    else{
      //return 0
      pres = 0
    }
    return $filter("number")(num, pres)
  };
}]);

//Usage.

{{number_with_long_decimals | decimalmax:4}} // 1234.456789 shows 1234.4567
{{number_with_long_decimals | decimalmax:2}} // 1234.456789 shows 1234.45