New Twiddle

controllers.application.js

import Ember from 'ember';

const {computed, on} = Ember;

const getFunctionName = function (fun) {
  var ret = fun.toString();
  ret = ret.substr('function '.length);
  ret = ret.substr(0, ret.indexOf('('));
  return ret;
};

const dynamicFilterBy = function(targetSource, sourceName, propertyNameKey, filterByKey){
	return on('init', function(){
    
    this[`_filterBy${targetSource}Setter`] = () => {
			   const cp = computed(`${sourceName}.@each.${this.get(propertyNameKey)}`, 		filterByKey, function(){
  	return this.get(sourceName).filterBy(this.get(propertyNameKey), this.get(filterByKey));
  });
    
    this.set(targetSource, cp);    	
    };
    // replace on function with a computed
    this[`_filterBy${targetSource}Setter`]();
    this.addObserver(propertyNameKey, this, function(){
      // reset computed
    	this[`_filterBy${targetSource}Setter`]();
    });
  });	
}

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  
  filterByValue: 'John',
  filterByProperty: 'name',
  
  users: [{
  	id: 1,
    name: 'John',
    email: '[email protected]',
    city: 'NY',
  },
  {
   id: 2,
   name: 'Lucy',
   email: '[email protected]',
   city: 'NY'
  },
  {
   id: 3,
   name: 'Oliver',
   email: '[email protected]',
   city: 'SF'
  }],
  
  filteredUsers: dynamicFilterBy('filteredUsers', 'users', 'filterByProperty', 'filterByValue'),
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}

FilterValue: {{input value=filterByValue}}
FilterProperty: {{input value=filterByProperty}}

<pre>
{{#each filteredUsers as |user|}}
	{{user.id}} / {{user.name}} / {{user.email}} / {{user.city}}
{{/each}}
</pre>

<br>
<br>

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": {}
}