New Twiddle

components.numeric-input.js

import Ember from 'ember';

const positiveDecimal = /^\.$|^\d+$|^\d+\.\d+$|^\-$/;

export default Ember.Component.extend({
  value: '',
  keyPress(event) {
    const newChar = String.fromCharCode(event.which);
    if (this.isCharValid(newChar)) {
      const currentValue = this.get('value');
      const proposedValue = currentValue + newChar;
      if (this.isValueValid(proposedValue)) {
        this.set('value', proposedValue);
      }
    }
  	return false; 
  },
  isCharValid(char) {
  	return /^[0-9]|\.|\-$/.test(char);
  },
  isValueValid(proposedValue) {
    // -?(\d+|\d+\.\d+|\.\d+)([eE][-+]?\d+)?
    return positiveDecimal.test(proposedValue);
  },
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle'
});

templates.application.hbs

{{numeric-input}}

templates.components.numeric-input.hbs

<input type="text" value={{value}}/>
<button>Increase value</button>
<button>Decrease value</button>

twiddle.json

{
  "version": "0.10.6",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.9.0",
    "ember-data": "2.9.0",
    "ember-template-compiler": "2.9.0",
    "ember-testing": "2.9.0"
  },
  "addons": {}
}