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

I ended up creating a modified directive of the above code to accept input and change the format on the fly...

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

           element.bind('keyup', function (inputValue, e) {
             var strinput = modelCtrl.$$rawModelValue;
             //filter user input
             var transformedInput = strinput ? strinput.replace(/[^,\d.-]/g,'') : null;
             //remove trailing 0
             if(transformedInput.charAt(0) <= '0'){
               transformedInput = null;
               modelCtrl.$setViewValue(transformedInput);
               modelCtrl.$render();
             }else{
               var decimalSplit = transformedInput.split(".")
               var intPart = decimalSplit[0];
               var decPart = decimalSplit[1];
               //remove previously formated number
               intPart = intPart.replace(/,/g, "");
               //split whole number into array of 3 digits
               if(intPart.length > 3){
                 var intDiv = Math.floor(intPart.length / 3);
                 var strfraction = [];
                 var i = intDiv,
                     j = 3;

                 while(intDiv > 0){
                   strfraction[intDiv] = intPart.slice(intPart.length-j,intPart.length - (j - 3));
                   j=j+3;
                   intDiv--;
                 }
                 var k = j-3;
                 if((intPart.length-k) > 0){
                   strfraction[0] = intPart.slice(0,intPart.length-k);
                 }
               }
               //join arrays
               if(strfraction == undefined){ return;}
                 var currencyformat = strfraction.join(',');
                 //check for leading comma
                 if(currencyformat.charAt(0)==','){
                   currencyformat = currencyformat.slice(1);
                 }

                 if(decPart ==  undefined){
                   modelCtrl.$setViewValue(currencyformat);
                   modelCtrl.$render();
                   return;
                 }else{
                   currencyformat = currencyformat + "." + decPart.slice(0,2);
                   modelCtrl.$setViewValue(currencyformat);
                   modelCtrl.$render();
                 }
             }
            });
      }
  };

})