How do I restrict an input to only accept numbers?

Question

I am using ngChange in AngularJS to trigger a custom function that will remove any letters the user adds to the input.

Answer 1

you may also want to remove the 0 at the beginning of the input... I simply add an if block to Mordred answer above because I cannot make a comment yet...

  app.directive('numericOnly', function() {
    return {
      require: 'ngModel',
      link: function(scope, element, attrs, modelCtrl) {

          modelCtrl.$parsers.push(function (inputValue) {
              var transformedInput = inputValue ? inputValue.replace(/[^\d.-]/g,'') : null;

              if (transformedInput!=inputValue) {
                  modelCtrl.$setViewValue(transformedInput);
                  modelCtrl.$render();
              }
              //clear beginning 0
              if(transformedInput == 0){
                modelCtrl.$setViewValue(null);
                modelCtrl.$render();
              }
              return transformedInput;
          });
      }
    };
  })