Apply number filter on input field in AngularJS

You can't apply a filter to ng-model.

See specifically this answer (not marked as the answer) for more information: https://stackoverflow.com/a/14425022/1452497

Short and sweet:

...the intention of AngularJS inputs and the ngModel directive is that invalid input should never end up in the model. The model should be always valid.

Consider also that the expression inside of ng-model needs to be assignable from the parser.

ng-model="testA" eventually breaks down to: testA = some-input-value

This wouldn't work as: testA | number:2 = some-input-value

You should use a formatter or parser for this (outside of the view).

This error: 
Error: [ngModel:numfmt] http://errors.angularjs.org/1.3.5/ngModel/numfmt?p0=1
check your model: don't using $scope.mymodel = '1';
to use $scope.mymodel = 1;

This directive validate only numbers on input.

angularMainModule.directive('onlyNumbers', function() {
    return function(scope, element, attrs) {
        var keyCode = [8,9,37,39,48,49,50,51,52,53,54,55,56,57,
                     96,97,98,99,100,101,102,103,104,105,110];
        element.bind("keydown", function(event) {
            if($.inArray(event.which,keyCode) == -1) {
                 scope.$apply(function(){
                     scope.$eval(attrs.onlyNumbers);
                     event.preventDefault();`enter code here`
                 });
                 event.preventDefault();
            }
        });
    };
});