OnlyDiscount Validation in Iput Type in Angular 2

<input type="text"  OnlyDiscount="true" > -- Html Code here

First Create Directive.ts File and Put Code Inside

*************************onlydiscount.directive.ts***************************


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

@Directive({
  selector: '[OnlyDiscount]'
})
export class OnlyDiscount {

  constructor(private el: ElementRef) { }

  @Input() OnlyDiscount: boolean;

  @HostListener('keydown', ['$event']) onKeyDown(event) {
    let e = <KeyboardEvent>event;
    if (e.which == 13) {
      e.preventDefault();
      var $next = $('[tabIndex=' + (+ parseInt(e.target['tabIndex']) + 1) + ']');
      if (!$next.length) {
        $next = $('[tabIndex=1]');
      }
      $next.focus();

    }
    else if (this.OnlyDiscount) {
      var input = <HTMLInputElement>event.srcElement;
      var inputVal = input.value;
      if (event.keyCode == 8 || event.keyCode == 46 || event.keyCode == 37 || event.keyCode == 39) {
        return true;
      }
      else if (parseInt(inputVal + e.key) > 99) {
        e.preventDefault();
      }
      else if (inputVal.indexOf('.') > -1 && e.key == ".") {
        e.preventDefault();
      }
      else if (parseFloat(inputVal) * 100 % 1 > 0) {
        e.preventDefault();
      }
      else if ([46, 8, 9, 27, 13, 110, 190].indexOf(e.keyCode) !== -1 ||
        // Allow: Ctrl+A
        (e.keyCode == 65 && e.ctrlKey === true) ||
        // Allow: Ctrl+C
        (e.keyCode == 67 && e.ctrlKey === true) ||
        // Allow: Ctrl+X
        (e.keyCode == 88 && e.ctrlKey === true) ||
        // Allow: home, end, left, right
        (e.keyCode >= 35 && e.keyCode <= 39)) {
        // let it happen, don't do anything
        return;
      }
      // Ensure that it is a number and stop the keypress
      else if ((e.shiftKey || (e.keyCode < 48 || e.keyCode > 57)) && (e.keyCode < 96 || e.keyCode > 105)) {

        e.preventDefault();
      }
    }
  }
}


/*
Copyright 2016 Google Inc. All Rights Reserved.
Use of this source code is governed by an MIT-style license that
can be found in the LICENSE file at http://angular.io/license
*/