Simple Input Mask

controllers.application.js

import Ember from 'ember';

const {
  get,
  set
} = Ember;

export default Ember.Controller.extend({
  actions: {
    updateSsn(event) {
      let user = get(this, 'model');
      let value = event.target.value;
      let newSsn = value.replace(/-/g, '');

      if (newSsn.length <= 9) {
        set(user, 'ssn', newSsn);
      }

      user.notifyPropertyChange('ssn');
    }
  }
});

models.user.js

import Model from 'ember-data/model';
import attr from 'ember-data/attr';

export default Model.extend({
  name: attr('string'),
  ssn: attr('string'),

  formattedSsn: Ember.computed('ssn', function() {
    let ssn = this.get('ssn') || '';
    let first = ssn.toString().substr(0, 3);
    let second = ssn.toString().substr(3, 2);
    let third = ssn.toString().substr(5, 4);

  	let formattedSsn = '';
    if (first) {
      formattedSsn += first;
      if (first.length === 3) {
        formattedSsn += '-';
      }
    }
    if (second) {
      formattedSsn += second;
      if (second.length === 2) {
        formattedSsn += '-';
      }
    }
    if (third) {
      formattedSsn += third;
    }
    
    return formattedSsn;
  })
});

routes.application.js

import Ember from 'ember';

export default Ember.Route.extend({
  model() {
    return this.get('store').createRecord('user', {
      name: 'Alex',
      ssn: ''
    });
  }
});

templates.application.hbs

<h1>Simple Input Mask</h1>

<form>
  <p>
    <label>Name:</label>
    {{input value=model.name}}
  </p>
  <p>
    <label>SSN:</label>
    <input
      value={{model.formattedSsn}}
      oninput={{action "updateSsn"}}
      pattern="\d{3}-?\d{2}-?\d{4}"
      required>
  </p>
  <button type="submit">Submit</button>
</form>

<p>model.name={{model.name}}</p>
<p>model.ssn={{model.ssn}}</p>
<p>model.formattedSsn={{model.formattedSsn}}</p>

twiddle.json

{
  "version": "0.13.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.16.2",
    "ember-template-compiler": "2.16.2",
    "ember-testing": "2.16.2"
  },
  "addons": {
    "ember-data": "2.16.3"
  }
}