client side data integrity

components.custom-input.js

import Ember from 'ember';

export default Ember.Component.extend({
});

controllers.application.js

import Ember from 'ember';
import { typeOf } from '@ember/utils';

export default Ember.Controller.extend({
  init() {
    this._super(...arguments);
    let model = {};
    Object.defineProperty(model, 'data', {
      writable: false,
      configurable: true,
      value: 'Goku'
    });
    this.set('model', model);
    Ember.onerror = function(error) {
		  if (typeOf(error) === 'error') {
        alert(error);
		  }
    }
  },
  appName: 'Ember Twiddle',
  
  actions: {
    focusIn(property) {
      Object.defineProperty(this.get('model'), property, {
        writable: true
      });
    },
    
    focusOut(property) {
      Object.defineProperty(this.get('model'), property, {
        writable: false
      });
    },
    
  	change() {
    	this.set('model.data', this.get('model.data') + this.get('model.data'));
    },
    
    send() {
      alert(`${this.get('model.data')} is sent to server`);
    }
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
Name(immutable): {{input value=model.data focusOut=(action "focusOut" "data") focusIn=(action "focusIn" "data")}}
{{!--<button {{action "focusIn"}}>Change as writable</button>
<button {{action "focusOut"}}>Change as not-writable</button>--}}
<br><br>
<button {{action "send"}}>Send</button>
<br><br><br>
This `change` function tries to change the `name` value.
An error will be thrown since it is read-only.
<br><br>
<button {{action "change"}}>Change</button>
<br><br>
We can catch this error while implementing in the app and send it as error log.
{{outlet}}
<br>
<br>

templates.components.custom-input.hbs

<select onchange={{action (mut value) value="target.value"}}>
{{#each content as |option|}}
	<option value={{option.name}}>{{option.name}}</option>
{{/each}}
</select>

twiddle.json

{
  "version": "0.15.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.2.2",
    "ember-template-compiler": "3.2.2",
    "ember-testing": "3.2.2"
  },
  "addons": {
    "ember-data": "3.2.0"
  }
}