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.

<input type="text" name="inputName" data-ng-change="numbersOnly()"/>

The problem is that I need to target the input that triggered numbersOnly() so that I can remove the letters entered. I have looked long and hard on Google and was unable to find anything regarding this.

What can I do?

Answer 1

Easy way , use type="number" if it works for your use case:

<input type="number" ng-model="myText" name="inputName">

Another easy way: ng-pattern can also be used to define a regex that will limit what is allowed in the field. See also the "cookbook" page about forms .

Hackish? way , $watch the ng-model in your controller:

<input type="text"  ng-model="myText" name="inputName">

Controller:

$scope.$watch('myText', function() {
   // put numbersOnly() logic here, e.g.:
   if ($scope.myText  ... regex to look for ... ) {
      // strip out the non-numbers
   }
})

Best way , use a $parser in a directive. I'm not going to repeat the already good answer provided by @pkozlowski.opensource, so here's the link: https://stackoverflow.com/a/14425022/215945

All of the above solutions involve using ng-model, which make finding this unnecessary.

Using ng-change will cause problems. See AngularJS - reset of $scope.value doesn't change value in template (random behavior)

Answer 2

Using ng-pattern on the text field:

<input type="text"  ng-model="myText" name="inputName" ng-pattern="onlyNumbers">

Then include this on your controller

$scope.onlyNumbers = /^\d+$/;

Answer 3

Here's my implementation of the $parser solution that @Mark Rajcok recommends as the best method. It's essentially @pkozlowski.opensource's excellent $parser for text answer but rewritten to only allow numerics. All credit goes to him, this is just to save you the 5 minutes of reading that answer and then rewriting your own:

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();
                }

                return transformedInput;
            });
        }
    };
});

And you'd use it like this:

<input type="text" name="number" ng-model="num_things" numeric-only>

Interestingly, spaces never reach the parser unless surrounded by an alphanumeric, so you'd have to .trim() as needed. Also, this parser does NOT work on <input type="number"> . For some reason, non-numerics never make it to the parser where they'd be removed, but they do make it into the input control itself.

Answer 4

None of the solutions proposed worked fine for me, and after a couple of hours I finally found the way.

This is the angular directive:

angular.module('app').directive('restrictTo', function() {
    return {
        restrict: 'A',
        link: function (scope, element, attrs) {
            var re = RegExp(attrs.restrictTo);
            var exclude = /Backspace|Enter|Tab|Delete|Del|ArrowUp|Up|ArrowDown|Down|ArrowLeft|Left|ArrowRight|Right/;

            element[0].addEventListener('keydown', function(event) {
                if (!exclude.test(event.key) && !re.test(event.key)) {
                    event.preventDefault();
                }
            });
        }
    }
});

And the input would look like:

<input type="number" min="0" name="inputName" ng-model="myModel" restrict-to="[0-9]">

The regular expression evaluates the pressed key, not the value .

It also works perfectly with inputs type="number" because prevents from changing its value, so the key is never displayed and it does not mess with the model.

Answer 5

这里是一个不错的解决方案，也只允许输入数字的input ：

<input type="text" ng-model="myText" name="inputName" onkeypress='return event.charCode >= 48 && event.charCode <= 57'/>

Answer 6

There are a few ways to do this.

You could use type="number" :

<input type="number" />

Alternatively - I created a reuseable directive for this that uses a regular expression.

Html

<div ng-app="myawesomeapp">
    test: <input restrict-input="^[0-9-]*$" maxlength="20" type="text" class="test" />
</div>

Javascript

;(function(){
    var app = angular.module('myawesomeapp',[])
    .directive('restrictInput', [function(){

        return {
            restrict: 'A',
            link: function (scope, element, attrs) {
                var ele = element[0];
                var regex = RegExp(attrs.restrictInput);
                var value = ele.value;

                ele.addEventListener('keyup',function(e){
                    if (regex.test(ele.value)){
                        value = ele.value;
                    }else{
                        ele.value = value;
                    }
                });
            }
        };
    }]);    
}());

Answer 7

All the above solutions are quite large, i wanted to give my 2 cents on this.

I am only checking if the value inputed is a number or not, and checking if it's not blank, that's all.

Here is the html:

<input type="text" ng-keypress="CheckNumber()"/>

Here is the JS:

$scope.CheckKey = function () {
    if (isNaN(event.key) || event.key === ' ' || event.key === '') {
        event.returnValue = '';
    }
};

It's quite simple.

I belive this wont work on Paste tho, just so it's known.

For Paste, i think you would need to use the onChange event and parse the whole string, quite another beast the tamme. This is specific for typing.

UPDATE for Paste : just add this JS function:

$scope.CheckPaste = function () {
    var paste = event.clipboardData.getData('text');

    if (isNaN(paste)) {
        event.preventDefault();
        return false;
    }
};

And the html input add the trigger:

<input type="text" ng-paste="CheckPaste()"/>

I hope this helps o/

Answer 8

Here is a Plunker handling any situation above proposition do not handle.
By using $formatters and $parsers pipeline and avoiding type="number"

And here is the explanation of problems/solutions (also available in the Plunker) :

/*
 *
 * Limit input text for floating numbers.
 * It does not display characters and can limit the Float value to X numbers of integers and X numbers of decimals.
 * min and max attributes can be added. They can be Integers as well as Floating values.
 *
 * value needed    |    directive
 * ------------------------------------
 * 55              |    max-integer="2"
 * 55.55           |    max-integer="4" decimal="2" (decimals are substracted from total length. Same logic as database NUMBER type)
 *
 *
 * Input type="number" (HTML5)
 *
 * Browser compatibility for input type="number" :
 * Chrome : - if first letter is a String : allows everything
 *          - if first letter is a Integer : allows [0-9] and "." and "e" (exponential)
 * Firefox : allows everything
 * Internet Explorer : allows everything
 *
 * Why you should not use input type="number" :
 * When using input type="number" the $parser pipeline of ngModel controller won't be able to access NaN values.
 * For example : viewValue = '1e'  -> $parsers parameter value = "".
 * This is because undefined values are not allowes by default (which can be changed, but better not do it)
 * This makes it impossible to modify the view and model value; to get the view value, pop last character, apply to the view and return to the model.
 *
 * About the ngModel controller pipelines :
 * view value -> $parsers -> model value
 * model value -> $formatters -> view value
 *
 * About the $parsers pipeline :
 * It is an array of functions executed in ascending order.
 * When used with input type="number" :
 * This array has 2 default functions, one of them transforms the datatype of the value from String to Number.
 * To be able to change the value easier (substring), it is better to have access to a String rather than a Number.
 * To access a String, the custom function added to the $parsers pipeline should be unshifted rather than pushed.
 * Unshift gives the closest access to the view.
 *
 * About the $formatters pipeline :
 * It is executed in descending order
 * When used with input type="number"
 * Default function transforms the value datatype from Number to String.
 * To access a String, push to this pipeline. (push brings the function closest to the view value)
 *
 * The flow :
 * When changing ngModel where the directive stands : (In this case only the view has to be changed. $parsers returns the changed model)
 *     -When the value do not has to be modified :
 *     $parsers -> $render();
 *     -When the value has to be modified :
 *     $parsers(view value) --(does view needs to be changed?) -> $render();
 *       |                                  |
 *       |                     $setViewValue(changedViewValue)
 *       |                                  |
 *       --<-------<---------<--------<------
 *
 * When changing ngModel where the directive does not stand :
 *     - When the value does not has to be modified :
 *       -$formatters(model value)-->-- view value
 *     -When the value has to be changed
 *       -$formatters(model vale)-->--(does the value has to be modified) -- (when loop $parsers loop is finished, return modified value)-->view value
 *                                              |
 *                                  $setViewValue(notChangedValue) giving back the non changed value allows the $parsers handle the 'bad' value
 *                                               |                  and avoids it to think the value did not changed
 *                Changed the model <----(the above $parsers loop occurs)
 *
 */

Answer 9

   <input type="text" name="profileChildCount" id="profileChildCount" ng-model="profile.ChildCount" numeric-only maxlength="1" />

您可以使用仅数字属性。

Answer 10

DECIMAL

directive('decimal', function() {
                return {
                    require: 'ngModel',
                    restrict: 'A',
                    link: function(scope, element, attr, ctrl) {
                        function inputValue(val) {
                            if (val) {
                                var digits = val.replace(/[^0-9.]/g, '');

                                if (digits.split('.').length > 2) {
                                    digits = digits.substring(0, digits.length - 1);
                                }

                                if (digits !== val) {
                                    ctrl.$setViewValue(digits);
                                    ctrl.$render();
                                }
                                return parseFloat(digits);
                            }
                            return "";
                        }
                        ctrl.$parsers.push(inputValue);
                    }
                };
            });

DIGITS

directive('entero', function() {
            return {
                require: 'ngModel',
                restrict: 'A',
                link: function(scope, element, attr, ctrl) {
                    function inputValue(val) {
                        if (val) {
                            var value = val + ''; //convert to string
                            var digits = value.replace(/[^0-9]/g, '');

                            if (digits !== value) {
                                ctrl.$setViewValue(digits);
                                ctrl.$render();
                            }
                            return parseInt(digits);
                        }
                        return "";
                    }
                    ctrl.$parsers.push(inputValue);
                }
            };
        });

angular directives for validate numbers

Answer 11

I know this is old, but I've created a directive for this purpose in case anyone is looking for an easy solution. Very simple to use.

You can check it out here .

Answer 12

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;
          });
      }
    };
  })

Answer 13

Basic HTML

<input type="number" />

Basic bootstrap

<input class="form-control" type="number" value="42" id="my-id">

Answer 14

Try this,

<input ng-keypress="validation($event)">

 function validation(event) {
    var theEvent = event || window.event;
    var key = theEvent.keyCode || theEvent.which;
    key = String.fromCharCode(key);
    var regex = /[0-9]|\./;
    if (!regex.test(key)) {
        theEvent.returnValue = false;
        if (theEvent.preventDefault) theEvent.preventDefault();
    }

}

Answer 15

SOLUTION: I make a directive for all inputs, number, text, or any, in the app, so you can input a value and change the event. Make for angular 6

 import { Directive, ElementRef, HostListener, Input } from '@angular/core';

 @Directive({
// tslint:disable-next-line:directive-selector
selector: 'input[inputType]'
})
  export class InputTypeDirective {
 constructor(private _el: ElementRef) {}

 @Input() inputType: string;
 // tipos: number, letter, cuit, tel

@HostListener('input', ['$event']) onInputChange(event) {
if (!event.data) {
  return;
}

switch (this.inputType) {
  case 'number': {
    const initalValue = this._el.nativeElement.value;
    this._el.nativeElement.value = initalValue.replace(/[^0-9]*/g, '');
    if (initalValue !== this._el.nativeElement.value) {
      event.stopPropagation();
    }
     break;
          }
       case 'text': {
        const result = event.data.match(/[^a-zA-Z Ññ]*/g);
        if (result[0] !== '') {
           const initalValue = this._el.nativeElement.value;
           this._el.nativeElement.value = initalValue.replace(
          /[^a-zA-Z Ññ]*/g,
           ''
         );
           event.stopPropagation();
        }
        break;
    }
        case 'tel':
          case 'cuit': {
         const initalValue = this._el.nativeElement.value;
      this._el.nativeElement.value = initalValue.replace(/[^0-9-]*/g, '');
       if (initalValue !== this._el.nativeElement.value) {
         event.stopPropagation();
       }
     }
   }
  }
   }

HTML

     <input matInput inputType="number" [formControlName]="field.name" [maxlength]="field.length" [placeholder]="field.label | translate"  type="text" class="filter-input">

Answer 16

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();
                 }
             }
            });
      }
  };

})

Answer 17

<input type="text" ng-model="employee.age" valid-input input-pattern="[^0-9]+" placeholder="Enter an age" />

<script>
var app = angular.module('app', []);

app.controller('dataCtrl', function($scope) {
});

app.directive('validInput', function() {
  return {
    require: '?ngModel',
    scope: {
      "inputPattern": '@'
    },
    link: function(scope, element, attrs, ngModelCtrl) {

      var regexp = null;

      if (scope.inputPattern !== undefined) {
        regexp = new RegExp(scope.inputPattern, "g");
      }

      if(!ngModelCtrl) {
        return;
      }

      ngModelCtrl.$parsers.push(function(val) {
        if (regexp) {
          var clean = val.replace(regexp, '');
          if (val !== clean) {
            ngModelCtrl.$setViewValue(clean);
            ngModelCtrl.$render();
          }
          return clean;
        }
        else {
          return val;
        }

      });

      element.bind('keypress', function(event) {
        if(event.keyCode === 32) {
          event.preventDefault();
        }
      });
    }
}}); </script>